# Small current leakage livestock trough heater



## archibald tuttle (Dec 30, 2011)

I maintain equipment for a farm which, at this time of year, includes several immersion heaters in the stock troughs. Since right around the dawn of [my] time at this job (30 years) we have had ground fault plugs for the heaters. Some of them are inside buildings but given the context of electric lines running into a bucket of water and animals standing on the ground and drinking from them it just seemed sensible to use them in all cases.

From time to time we get horses that won't drink from the troughs once we start running the heaters. I had tended to assume that there couldn't be any current leakage they might be sensing because the ground faults were never tripped. When this behavior occurred I would test the ground fault by taking very low load (e.g. small test light) from the hot prong directly to the ground instead of the neutral and they would snap right off. QED I thought.

So it started up again this year. We're using the same heater we used last year, same horses, drank fine last year, don't want to drink. Performed my field test, ground fault does just what it is supposed to, but while I was out there with the tester I just idly put one prong in the water and stuffed one into the ground and I was reading about 7 volts. Unplugged the heater and its gone. I tend to doubt that this is different than the previous year because the equipment is the same but I had never thought of testing like this before.

This is a plastic tank and I get that just having this minor potential on the water isn't a ground fault in and of itself, but realizing the fault (i.e. say by a horse drinking and/or I tried to duplicate that one better by putting a copper ground rod in and then laid some wire into the tank and attached it to the rod) and the GFI did not trip. The voltage potential between the water and the ground went down from 7 to 5. And this was not a spurious or poor reading, I could disconnect that wire from the ground rod and it went right back to 7. Tried it several times with identical results.

I then tried several different heaters of various ages and wattages and they all gave the same results. There is also another trough set up for donkeys who were drinking fine, but I found that same 7 volt potential between the water and the ground. Donkeys are lighter on their feet and seem to ground less well in our experience with electric fence as well, so this isn't surprising.

Given the results of this 'study' to date I am moved to conclude that the actual amount of amperage that this system is able to flow to ground must be very small so as not to trip the ground fault, and that in some years, for whatever reason the horses have not been sensitive to it,

I'm a little perplexed as to why I can't get the voltage to disappear by directly grounding the water although I'm thinking that although it improved conduction, it isn't actually that great a conductor. I'm also speculating that if our water weren't slightly acidic (rock water, wells in the ledge) maybe it wouldn't support any potential. I suppose I could lime the trough and see if it changes but this is all wild ass guesses from chemistry classes that predate this job, so that means more than 30 years ago.

I haven't tried additional ground rods or more wires in the trough but I was able to obtain the same 2 volt reduction by just throwing a bare wire in the trough and sticking the end an inch into the ground as I got from putting in a full ground rod, so I'm not really suspecting it is the quality of the ground but . . .

I don't really have a good grasp on what is going on, why this voltage is showing up and whether this represents faulty equipment or the norm. I have never tested a brand new heater, although these heaters vary from 1 to 3 years old and all give the same results.

Don't know if anyone has ever been called out on a problem like this or has any theoretical comment on what might be happening and whether it is something that should be rectified (meaning that in the non-technical sense).

thanks

perplexed in Exeter,


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## Dennis Alwon (May 9, 2009)

I highly recommend you listen to this video 
http://www.mikeholt.com/strayVoltageVideo.php


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## McClary’s Electrical (Feb 21, 2009)

I would meg from the element to ground. I think you have some failing elements


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## oliquir (Jan 13, 2011)

can you ground the outside of the heater directly,this would cut leakage at start point


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## archibald tuttle (Dec 30, 2011)

*thank you*

for getting to my problems so quickly on a holiday.

i am watching mike holt's video, but his troubleshooting to determine if the stray voltage is a utility problem is to turn off your circuit breaker and see if you still have the voltage. I don't have the voltage when I unplug the heater, which is essentially a micro version of turning off the breaker. I feel that it must be leaking from the heater although I'm fascinated by MIke's video and have to delve into that and the relevancre to bonding neutral and ground.

sounds like it doesn't really change matters because the voltage is still a matter of the drop going back to the substation.

anyway i'm stuck on my fascination with mike but I'm going to go out right now and ground the element itself. I don't know why I didn't think of that. results later.

thanks brian


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## archibald tuttle (Dec 30, 2011)

oliquir said:


> can you ground the outside of the heater directly,this would cut leakage at start point


The heater is essentially an exposed element much like the element in a typical residential hot water heater. I'm going to try wrapping the ground wire several times around the surface of the this element and will report results.

for those interested in seeing what one looks like it is a farm innovators H-439

thanks again.

results a little later.

brian


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## Dennis Alwon (May 9, 2009)

I am not certain why the gfc does not trip. Is the heater grounded? If it is then the current from the earth- if that is the issue- is running from earth thru the animal to the ground on the heater. This should not trip the gfci as the GFCI will still read the voltage thru the heater consistently.

A equipotential grid should solve the issue or you can try and get the poco involved. The voltage may be coming from the feeder to the barn if there is a break or cut in the wire.


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## archibald tuttle (Dec 30, 2011)

*results of latest evaluations*



Dennis Alwon said:


> I am not certain why the gfc does not trip. Is the heater grounded? If it is then the current from the earth- if that is the issue- is running from earth thru the animal to the ground on the heater. This should not trip the gfci as the GFCI will still read the voltage thru the heater consistently.
> 
> A equipotential grid should solve the issue or you can try and get the poco involved. The voltage may be coming from the feeder to the barn if there is a break or cut in the wire.


Wrapped a wire from the ground rod directly around the heating element and didnt notice any significant change. The voltage has changed a little since I began testing which goes to Mike Holt's presentation that the voltage will vary with load. it's a littler later in the morning not everybody getting up and turning lights on and using hot water so usage is probably down.

I am measuring that same voltage from the neutral wire to ground so I guess because of the neutral bond the ground on the trough heater is actually the culprit. Mike said in his presentation that grounding doesn't do any good and that should seem obvious since there are grounds at the poles and at the services etc. 

It's counterintuitive that you can have all these grounds and still have a potential to ground, so maybe it is a question of enough grounds and you just can't have enough given the amount of current entailed because you'd have to flow to ground as much current as is being used from the substation, less any that is making ground as result of all the existing grounds. That just may be more ground contact than it is feasible to establish even with every service between here and the substation grounded in several places and neutral bonds to ground at every service.

going to the ag side of the world, it sounds like some folks use rubber matts to isolate their animals from the ground.

I don't have a concrete floor here that I could even find rebar to create any kind of equi-potential by bonding that to the potential.

It sounded like the test he proposed was pulling the neutral service wire briefly to see if the potential was on our side or the other. I'd have to make sure at least every voltage sensitive load was off to try that. I guess I could just kill the mains briefly and then try that test to insure that it is on the power company side.

Once I've established that then it looks like negotiating the install of a second transformer and installing devices to interrupt the neutral bond of the cable and phone lines. I suppose maybe there is some kind of equi-potential matt I could bury in the dirt that would approximate the approx to the concrete slab, maybe I could just bury some reinforcing mesh for slab concrete 6 or 8" where the horses wouldn't paw it up before going to do battel with the electric company.

While cheap digital meters might not be accurate I checked with analog as well and I'm showing at this moment both on the digital and analog meters about 3 to 3.5 volts.

do I have the check procedure right, i.e. kill the mains and pull the neutral and see if the voltage is on the line side?

thanks


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## archibald tuttle (Dec 30, 2011)

Dennis,

sorry quoted you and didn't respond. I'm assuming that as long as the same amount of current is running both legs of the ground fault it won't trip. This potential to ground is on either side but doesn't affect the current flow in the circuit if I undersrtand this stuff at all.


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## archibald tuttle (Dec 30, 2011)

PS -thing that blows my mind is that all these setups are the same as last year. unfortunately I wasn't monitoring consistently for stray voltage. no major changes on the grid near us and I would assume its the same as last year but can't say for sure.

maybe supply wire from the substation is atrophing or load increasing as mike holt speaks about so current and resistance might both be going up over time and it has reached a point of disturbance this year that was not evidenct to horses last year


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## green light (Oct 12, 2011)

It seems there was a thread here a month or two ago where a guy was describing the same problem. I did a search for the thread but couldnt find anything. If you have the time you may go back and look for it.


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## hardworkingstiff (Jan 22, 2007)

archibald tuttle said:


> do I have the check procedure right, i.e. kill the mains and pull the neutral and see if the voltage is on the line side?
> 
> thanks


 Yes, that will tell you if the power company is inducing current to your grounding system.

But, from what I think I've read about your problem, when you unplug the heater the problem goes away. Does this hold true if you turn the power off and leave the heater plugged in? See, when you unplug the heater, you disconnect the ground but when you turn off the breaker, the ground stays connected. 

If indeed this current is coming from the PoCo grounded conductor, you might be able to minimize the problem by driving some ground rods around the trough and bringing a ground wire back to the neutral/GEC connection made at the service equipment.

Edit: If you have a sub panel out by the equipment, you can always take this new ground wire to the ground bar of the sub panel and probably get the same effect.


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## JacksonburgFarmer (Jul 5, 2008)

Do you have a equipotential ground in place around the water troughs? Is this on concrete or rebar? This can be a issue on farms, often coming from the utility. The best way to remedy this situation is a equipotential ground grid around the waters. This way the animals are brought to the same potential as any water/surface/metal that they come in contact with.


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## archibald tuttle (Dec 30, 2011)

*more results/quick fix*



green light said:


> It seems there was a thread here a month or two ago where a guy was describing the same problem. I did a search for the thread but couldnt find anything. If you have the time you may go back and look for it.


I will take a look, I don't like to make everyone cover the same ground and maybe there were other suggestions although apparently the latency period for this discussion is just long enough to flush it off the active threads.

I didn't know to call this stray voltage or as Mike Holt calls it NEV so now i have something to search on. meanwhile . . . back at the farm:

So the light bulb over my head finally went off and I realized as i mentioned above but didn't think about what I was saying, there is no problem with the actual 120 hot to neutral circuit. its not leaking from there which is why the ground fault interrputer is not interrupting. the ground is bonded to the neutral back at the service and it is carrying the stray voltage out to the 3rd prong of all the plugs. I plug in the heater that has a grounding prong and throw it in the trough and I am introducing stray current to the trough from the at ground prong which is wired to all the exposed metal on the implement.

So I go digging around on my shelves until I can find one of the little 3 blade to 2 blade converters, throw that on and voila, voltage gone.

So I still need to test at the mains to make sure nothing on our place is the source and then I can, at a more leisurely pace try to figure out what if anything to do about this. and the voltage definitely varies with time of day and in all likelihood load going back to the substation, it was down to 2.4 during my latest round of testing.

so this is my first experience in wondering what the benefits are of bonding the house grounding to neutral? That is the practice in Rhode Island. I know that some areas are bonded and some are not. Obviously the lack of bonding would prevent this stray voltage from being seen on metal electric fixtures and piping.

On the other hand, unbonded ground may be less effective on conducting harmful spurious voltages away from potentially harmful occurences.

I'm sure I am opening a common [sorry] can of worms here bringing this up, but this is the first time I've experienced a negative consequence of bonding. perhaps unusual the thought should be so neophytic 30 years into thinking I knew how the world worked, but the world has shown me again and again that you can learn a lot of stuff, but never everything.

well, i'm trying god damn it. sorry should use that language during the 12 days of christmas -- or any other time according to my wife.

enjoy the yule the festival of lights and look forward to you talking amongst yourselves or pointing me to long acerbic threads on the merits of ground bonding.

brian


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## oliquir (Jan 13, 2011)

since you have unplugged ground from service i would put a ground rod near the water and connect ground of heaters to this rod. if you leave it unconnected, the gfi will not see defective heaters


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## Dennis Alwon (May 9, 2009)

Well it sounds like you found the source as ground voltage or stray voltage. Now is it coming from the feeder wire to the barn or from the poco. I would install the equipotential grid under the trough area and see if that helps but I would also call the poco and see what is going on if it is not coming from the feeder.

Turn the power off from the main supply to the barn. Plug the heater with the ground connected- no power needed and see if you still have the issue. If you do then it is a poco issue otherwise it is your problem.


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## hardworkingstiff (Jan 22, 2007)

Dennis Alwon said:


> If you do then it is a poco issue .....


And the answer I got from PoCo is we had inadequate grounding.


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## FireInTheWire (Oct 30, 2011)

I like this thread- very interesting!


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## Dennis Alwon (May 9, 2009)

hardworkingstiff said:


> And the answer I got from PoCo is we had inadequate grounding.


Yep, they are not always easy to deal with. I have heard in rural areas where there are many farms some pocos are very responsive.


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## hardworkingstiff (Jan 22, 2007)

Is there any way to tell if the PoCo induced voltage (on the grounded conductor) is a result of expected voltage drop on the grid or if it is caused by a connection going bad?


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## Dennis Alwon (May 9, 2009)

hardworkingstiff said:


> Is there any way to tell if the PoCo induced voltage (on the grounded conductor) is a result of expected voltage drop on the grid or if it is caused by a connection going bad?


I am not certain but a 7 volt reading thru the dirt seems awfully high to me.


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## joethemechanic (Sep 21, 2011)

Dennis Alwon said:


> I am not certain but a 7 volt reading thru the dirt seems awfully high to me.


Yeah seriously high


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## Stab&Shoot (Aug 23, 2011)

Awesome thread!


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## chicken steve (Mar 22, 2011)

Brian,
it seems to me , reading through your dilema, what you really need is Kirchoff's commando's 

yanno, many get him wrong in that electricity takes_ the_ path of least resistance, it takes _all _paths relative to resistance

so you see, if you can wrap your head around that concept, all the grounding and bonding you may engage in may simply _aid and abet_ said _return_ to the serving xformer

much of what art547 dictates isolates this effect, but if your in a tight area with municipal H2O , or other utilities common to the serving xformer, those options may have less efficy....

~CS~


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## archibald tuttle (Dec 30, 2011)

*equipotential ground matt vs. 2 wire installation*



oliquir said:


> since you have unplugged ground from service i would put a ground rod near the water and connect ground of heaters to this rod. if you leave it unconnected, the gfi will not see defective heaters


My understanding is that the equipment ground is not necessary to the function of the GFI. It doesn't matter if the voltage is lost to the equipment ground conductor or to earth. Protection is equally afford to two wire as three wire. lack of an equipment ground does mean that the fault if it were to occur would be realized rather than awaiting some party, e.g. horse or human to come complete the circuit to ground although barring the ground fault failing on there still would be protection. So this may be an argument for a separate ground, esp. for a water tank implement as well as for pressing the test button regularly.

I mostly have experienced ground faults failing off rather than failing on. I'm trying to remember if I have ever had one fail on. 

But all this gets me right back to the discussion about bonding the ground in the first place. If it weren't bonded to the neutral and were just earthed then the NEV current would not be introduced by the equipment ground in the first place.

So short term I'll lead the tab from the adapter to an earth ground and then I think I'll have a protem fix and hopefully get the horses back to drinking while I talk this over with one of the linemen from the grid that I know.

thanks again for all the attention this question has received.

brian


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## chicken steve (Mar 22, 2011)

Brian

you need an MBJ _somewhere_ at the facility serving the feeder to the horse barn

earth grounds are not to be confused with , _or_ subsituted for this

~CS~


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## archibald tuttle (Dec 30, 2011)

*ok, i give, what's a MBJ*



chicken steve said:


> Brian
> 
> you need an MBJ _somewhere_ at the facility serving the feeder to the horse barn
> 
> ...


since this is a family thread I won't make any off color comments on what it could stand for.


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## archibald tuttle (Dec 30, 2011)

Dennis Alwon said:


> I am not certain but a 7 volt reading thru the dirt seems awfully high to me.


to clarify, i read 6.9 or 7 volts last night. read lower this morning (5) and lower still mid day (around 3). These readings were with a cheap digital multi-meter. Mike HOlt recommended and analog I believe in that video. I did get an analog and put it side this afternoon and got an identical reading to the digital. And this does coordinate with Holt's point that the size of NEV voltage is a function of the resistance on the neutral conductor and the amount of current being drawn which would be expected to go up in evening as it gets dark and people get home and again in the morning when people get up and use hot water, cook, etc.

dam straight that 7 volts seems high. from what Holt was saying over a volt is essentially too much or maybe even over a part of one volt.

brian


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## archibald tuttle (Dec 30, 2011)

*all paths lead to rome[x]*



chicken steve said:


> Brian,
> it seems to me , reading through your dilema, what you really need is Kirchoff's commando's
> 
> yanno, many get him wrong in that electricity takes_ the_ path of least resistance, it takes _all _paths relative to resistance
> ...


don't get the reference to Kirchoff or art547. probably have not hung out here enough.

as far as it taking all paths relative to resistance I think that is an important concept. that is why we have GFIs instead of just equipment grounds, because theoretically and equipment ground of copper wire should have less reistance than a person but if the current is loose it will take all paths including through the person . . . 

i agree this is important to recall.

no question that all the bonding (including that of the phone and cable company)keeps offering ways to get to this NEV and they are backdooring through the very equipment grounds that we are counting on to be the significant drains in the event of high current leakage but they are providing pathway for stray voltage. I now realize this is why I've been getting edgy zaps occasionally when using water with diamond wheels in electric grinders even thought they are hooked up to ground faults. ground fault doesn't trip but I havbe definitely gotten a couple buzzes.

so I'm taking it that neutral bonding serves a similar function in the sense that it may reduce the resistance encountered by large amounts of lose current seeking earth when a piece of equipment or wire fails but it provides transmission of nuisance and potentially hazardous if generally less deadly NEV in return for whatever margin of safety it is able to add to the equipment ground regimen.

Since I know there are regions that don't bond, I guess you can reason this risk benefit a couple ways and/or it may be related to the equipment used by the Poco as well which may push that equation one way or another and may be related to conventions established a long time ago in these regions that can't be reversed without literally building a new grid.

Somebody feel free to put out of my misery of guesswork here.

brian


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## green light (Oct 12, 2011)

archibald tuttle said:


> don't get the reference to Kirchoff or art547. probably have not hung out here enough.


 547=ag buildings:001_huh:


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## wcord (Jan 23, 2011)

I had a similar voltage to ground a few years ago. I discovered it one day when my satellite (10 ft) started acting up. Turned out, i had 7 volts running out on the cloths line (messenger support cable) to the 4 inch rigid steel post.
I had the power company drive in 3 more ground rods ( 1 in a slough) and I added 4 more on the farm property. With all the extra rods, we still had 5 volts running to ground.
As with you, I always thought that a GFCI would protect against tingle voltage. 
Here is a great article
http://www.omafra.gov.on.ca/english/livestock/dairy/facts/strayvol.htm


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## dmxtothemax (Jun 15, 2010)

It is not unusual for heating elements with a jacket,
to have some leakage to ground.
What material is the jacket of the heating element made of ?
If it is a metal, you could try putting a ground wire
directily on there.
Hopefully the leakage will not be enough to trip gfci's.
Like you said, fresh water is not always a GOOD conductor.
It has to have some impurities in it, or salt to be a GOOD conductor.


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## archibald tuttle (Dec 30, 2011)

*tried grounding the element directly . . .*



dmxtothemax said:


> It is not unusual for heating elements with a jacket,
> to have some leakage to ground.
> What material is the jacket of the heating element made of ?
> If it is a metal, you could try putting a ground wire
> ...


. . . to no effect. It would not surprise me that an economical heater could develop such leakage but this voltage is present from the neutral to earth with the heater completely unplugged and in buildings several hundred yards away so I do not think it is the heater in this case. I haven't performed the acid test at the mains yet as there are several residences and I need to prepare the residents for the power to go off and I'm having several hundred of my best friends over for new years day, so I think this will have to wait until next week for a final confirmation that the NEV is on the poco side and not related to a poor neutral connection or something on my side. 

I would think if I had bad neutral we would tend to notice voltage fluctuations with imbalanced loads across the two hot legs. Never found stray voltage (although I imagine there theoretically was some) when a burndy connection rotted at the pole on one of our outbuildings but I did notice the immediate effect as suddenly some lights dimmed and some went bright. Finished that day by turning loads on and off until they were pretty close to balanced and then went over the service from one end to the other and finally found the concealed problem.

But that was a virtual complete failure. It had been a problem for a while where this would happen intermittently, and then finally and conveniently it went altogether and I was able to isolate and track the problem. I suppose marginal conductivity through a splice would increase the voltage drop and thus give rise to localized potential on the neutral.

brian


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## Dennis Alwon (May 9, 2009)

archibald tuttle said:


> My understanding is that the equipment ground is not necessary to the function of the GFI.
> brian


That is correct. This is why we are allowed to replace 2 wire branch circuit receptacles with a 3 prong gfci receptacle or circuit breaker.

So now that you know the problem what are you going to do?


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## Dennis Alwon (May 9, 2009)

archibald tuttle said:


> to clarify, i read 6.9 or 7 volts last night. read lower this morning (5) and lower still mid day (around 3). These readings were with a cheap digital multi-meter. Mike HOlt recommended and analog I believe in that video.
> brian


That is why this is a poco issue. Remember as the voltage drop increases and the demand on the line increases there is more current to ground. Different times of the day the voltage will vary based on usage.


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## boots 211 (Aug 21, 2009)

I had similar experince at a cow barn, whenever the cooler kicked on for the milking equipment, it would send about 10 volts out to the watering cups and the stantions. When it would turn on you could drop a row of cows in the stantions right to the ground. Spent 2 days there, grounding everything, testing equipment, finally ended up changing the overhead service wire feeding the barn. It turned out to have a bad spot in the middle on the neutral wire, it was almost corroded through.


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## chicken steve (Mar 22, 2011)

Brian,
perhaps you could describe the farm layout, number of buildings , number of feeders , design and proximity of all , as well as nieghboring dwellings for the crew here to gain an overall pix?

~CS~


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## hardworkingstiff (Jan 22, 2007)

Just remember that a bad neutral connection (if that is contributing to this problem) does not necessarily have to be on the customer side of the meter. It could be somewhere up stream from your transformer, and since electricity takes all paths, the voltage drop by the system or the bad connection can sometimes show up as a voltage difference between the incoming (PoCo) neutral and the premise ground.

One of the big issues is getting PoCo to check for bad neutral connections. They always point to you and say you need better grounding.

Now, better grounding will take care of the symptom, but the problem will still be there. But, alas, with the design of our distribution system, I don't see how this problem ever gets solved.


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## archibald tuttle (Dec 30, 2011)

*description*



chicken steve said:


> Brian,
> perhaps you could describe the farm layout, number of buildings , number of feeders , design and proximity of all , as well as nieghboring dwellings for the crew here to gain an overall pix?
> 
> ~CS~


Chic,

three meters, two hundred amp services for two residence buildings one 60 amp service for large barn. The overhead service wires are minimalist by today's standards and it is conceivable there could be some extra connection problems there. I will also test to see if the NEV is similar at the farm next door that just got new service from their transformer because it got knocked out by the irene (more on irene later)

all our buildings are served from the same secondary drop coming from a single transformer on the road about 200 to 250 feet from the buildings. power currently comes overhead via one pole on the farm to weatherheads on the buildings.

There are several other smaller outbuildings served by conduits originating in the two residences. Ground rods of course at all the services. And grounds and neutrals bonded at the breaker boxes located at the service entries. (One subpanel in one of the residences and at two of the outbuildings also bonded and ground rods in the outbuidlings).

The problem exists everywhere including at outlets in the residential buildings not distant from the the service entry panel. I have not yet tried the test of pulling the neutral from the service to see if I find the voltage on the line side. will engage that later in the week when I can prep everybody and am not under the gun for other responsibilities.

Some of the runs to outbuildings are long although generally within acceptable voltage drops according to my understanding. most of them preexist my arrival here (you may recall the 30 year figure) and as I have mentioned in threads above one of the buildings (not here implicated) is a 700 foot run and has a 40 amp 240 v subpanel on #6 aluminum triplex that was here when I got here. That service lost its neutral (actually several times, once to abrasion from a tree and then later to a corroded connection at a burndy to copper entry wire (I actually remade that connection with noalox maybe 25 years ago). In those cases it was not NEV that alerted us to the problem but the more obvious loss of the balancing effect of the neutral to the loads such that the voltage on the legs would diverge unless the loads were carefully balanced. 

This was an intermittent problem at first and concealed under splicing compound and tape so it took me a little while to track it down. I basically took apart every splice and it was the last one.

That's last year's history, and I wasn't testing for NEV at the time. If I was regularly, it might have given me a tip that resitance (or is it impedance) was increasing on that line and I might have found the problem prophylactically rather than critically. 

In any event that is not the service where we are currently experiencing the problem with the livestock. The livestock tank is served out of the other residential building.

There is an electric fence in use with a single 10 ft. ground rod. Generally if there are any small electrical mysteries at outbuildings we will turn the fence off to make sure that is not causing any anomalies. Did that in this case as well and it made no difference.

Currently we don't have a permanently installed emergency generator (although santa brought us a propane generator, only a few months late for our date with Irene and a week of understanding how the old days were. that will get installed, although not likely before the spring).

I will be interested to see how the utility here works on NEV in rural settings. I certainly appreciate Mike Holt's serious take on the problem of NEV although I can see it is exacerbated by rural electrification and despite the benefit I now derive from our country's commitment to that plan I disagree completely with the economics of rural utility service at rates subsidized by those buying power in more concentrated demographics. I certainly don't blame the utilities for not being willing to almost literally reconstruct their services and grids at great expense to the bulk of customers to fix a problem that plagues a small number in no small part because of their remote location. (which means to say the manifestation of NEV as a serious problem vs. the question of whether it exists as noticeable or measurable phenomenon for a larger number of people).

The issues of expectations of electric utlitilies in rural areas were crystallized by Irene and all the needless paroxisms of folks who live around us and treat the area as if it were a suburb and demanded investigations of the utilities and claims that this big multi-national company didn't care about the local circumstance because it took them a week to patch things up after Irene. These folks obviously didn't live here as I did when Hurricane Bob came through in the mid 90s and we had a local utility -- Narragansett Elect -- and we were out for 3 weeks.

You can't move away from the problems of the city and then expect the city folks to solve all your 'problems' in the rural area like not getting your utilities back as quickly after a once a decade interruption, as if they are just supposed to pay crews to sit around doing nothing for ten years waiting for this minute. (there was little overlap in areas of outage form Irene and the recent Oct. snowstorm that brought down trees and powerlines, so there were a couple events close on the heels, but before that we have had no extended power outage since the mid 90s. so once a decade is about right).

I thought National Grid did an incredible job getting people up and running in a week (and mind you I hate National Grid for joining with the government to take their cut of a billion dollar plan to put up 6 windmills off block island, create 6 -- thats right 6 -- jobs makes the stimulus sound really effective and put a permanent IV into our wallets to pay for it and all under the rubric of improving utility rates on block island, like that is a problem to the average dude.) 
Well anyway I digress. I'm interested to see what Grid will do and to explore options but at the moment I feel like monitoring and separating the ground for the trough heaters would be the way to go. 

as far as an equipotential grid, that is an extensive amount of work to water a few animals. Although being a curious guy (that's what everybody says about me - is that a compliment?), I'm interested whether a rudimentary and effective grid could be created in non slab situations by burying garage mess bonded to the neutral or whether it is too light or would corrode too quickly. Anyone have any experience? But before I'd go through that I could put in a small hot water heater and just dispense hot water or put a physical not metal agitator in the water run by an electric motor that was not in the tank.

As a background question, the link in a post above to the canadian site suggests that the manufacturer of "tingle" isolaters up there stopped making them for lack of demand. It sounded like those were a pretty good solution and might cost less than a grand to install.

A good deal of the expense involved in installing those was separating grounds and neutral and then I believe the operation of this isolater was to provide a self closing connection between ground and neutral when maybe a certain voltage was acheived. Kind of like a scaled down version of a surge suppressor.

Is there anybody still making these in the states? Sounds like Mike HOlt's suggestion from the video, at least for a signficant ag installation, was for a second transformer. That seemed like it would be significnatly more expensive although it's funny how folks talk about these technologies without just coming out and saying how much they cost. And I don't know how this extra transformer affects the desired safety aspect of having the bonded neutral and ground.

Nough said. if you read to here, you like this kind of punishment.

brian


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## archibald tuttle (Dec 30, 2011)

*Hws*



hardworkingstiff said:


> Just remember that a bad neutral connection (if that is contributing to this problem) does not necessarily have to be on the customer side of the meter. It could be somewhere up stream from your transformer, and since electricity takes all paths, the voltage drop by the system or the bad connection can sometimes show up as a voltage difference between the incoming (PoCo) neutral and the premise ground.
> 
> One of the big issues is getting PoCo to check for bad neutral connections. They always point to you and say you need better grounding.
> 
> Now, better grounding will take care of the symptom, but the problem will still be there. But, alas, with the design of our distribution system, I don't see how this problem ever gets solved.


excellent point, in my marathon post above i realize that we could have a problem in the neutral connections in our close area but on the poco side of the meter. I'm going to try to get some testers going simultaneously at a couple neighbors and see if the NEV shows the same to rule in or out close problems, but of course it could be a junctions heading back toward the substation. At least if I can show that the neighbors have similar voltage that would help to make the case for looking at the poco system.

But as I've said above, they have to do that logically and keep it in mind while servicing because I'm not sure I expect them just to run every inch of wire between hear and the nearest substation which itself is a complicated question because we're near some kind of junction and maybe equidistant by some miles from a number of possibly involved stations.

brian


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## joethemechanic (Sep 21, 2011)

Put the heaters on the *ungrounded* side of an isolation transformer. Then there will be no neutral. Do not bond anything or carry your ground from the rest of the system. Run a ground to all your heaters to a completely separably derived ground rod/rods 50 feet or more from your service grounding rods (close to the salty pizzed soaked highly conductive place where the cattle stand to drink is a good place). But there will be no neutral, and no neutral-ground bond on the heater circuit.

Screw if it's code or not.

I've stood barefoot and put the phase wire to my tongue to prove this one.


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## joethemechanic (Sep 21, 2011)

BTW,

Don't get locked into thinking of the equipotential grid in _concrete_ means "portland concrete" with aggregate. 


Take a little dozer or loader out, scrape about a foot or two off the surface, lay out your grid, cover it with your original overburden with a very mild mix of lime in it. Compact it with the loader track and let the cattle pack it down hard, and it will get _very_ hard

Do not be afraid to substitute a backhoe, a gradeall, or whatever for the dozer, "we ain't building a church"


Oh and if you don't like lime for whatever reason , feel free to mix some portland in the overburden as a substitute


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## Dennis Alwon (May 9, 2009)

joethemechanic said:


> BTW,
> 
> Don't get locked into thinking of the equipotential grid in _concrete_ means "portland concrete" with aggregate.
> 
> ...


You also need to make it a voltage gradient ramp. If the animal steps from 7 volts to this grounded or bonded surface then they won't come in either.


----------



## chicken steve (Mar 22, 2011)

> Chic,
> 
> three meters, two hundred amp services for two residence buildings one 60 amp service for large barn. The overhead service wires are minimalist by today's standards and it is conceivable there could be some extra connection problems there. I will also test to see if the NEV is similar at the farm next door that just got new service from their transformer because it got knocked out by the irene (more on irene later)


 
well, i would think that prdent, not only for comparisson, but because it's sounding like the _only _recent major change here







> all our buildings are served from the same secondary drop coming from a single transformer on the road about 200 to 250 feet from the buildings. power currently comes overhead via one pole on the farm to weatherheads on the buildings.
> 
> There are several other smaller outbuildings served by conduits originating in the two residences. Ground rods of course at all the services. And grounds and neutrals bonded at the breaker boxes located at the service entries. (One subpanel in one of the residences and at two of the outbuildings also bonded and ground rods in the outbuidlings).
> 
> The problem exists everywhere including at outlets in the residential buildings not distant from the the service entry panel. I have not yet tried the test of pulling the neutral from the service to see if I find the voltage on the line side. will engage that later in the week when I can prep everybody and am not under the gun for other responsibilities.


 
Ok right here i think we may identify a _potential _Brian. Seems we have the typical farm scenario seen served via one common xformer, with multiple neutral bonds , or _main bonding jumpers_ (MBJ's) that marry the grounded & grounding conductor(s) @ the service entrance to all these buildings




> Some of the runs to outbuildings are long although generally within acceptable voltage drops according to my understanding. most of them preexist my arrival here (you may recall the 30 year figure) and as I have mentioned in threads above one of the buildings (not here implicated) is a 700 foot run and has a 40 amp 240 v subpanel on #6 aluminum triplex that was here when I got here. That service lost its neutral (actually several times, once to abrasion from a tree and then later to a corroded connection at a burndy to copper entry wire (I actually remade that connection with noalox maybe 25 years ago). In those cases it was not NEV that alerted us to the problem but the more obvious loss of the balancing effect of the neutral to the loads such that the voltage on the legs would diverge unless the loads were carefully balanced.
> 
> This was an intermittent problem at first and concealed under splicing compound and tape so it took me a little while to track it down. I basically took apart every splice and it was the last one.


 
　it's always the first or last splice......



> That's last year's history, and I wasn't testing for NEV at the time. If I was regularly, it might have given me a tip that resitance (or is it impedance) was increasing on that line and I might have found the problem prophylactically rather than critically.
> 
> In any event that is not the service where we are currently experiencing the problem with the livestock. The livestock tank is served out of the other residential building.


　thus the change @ your farm we're fishing for.....



> There is an electric fence in use with a single 10 ft. ground rod. Generally if there are any small electrical mysteries at outbuildings we will turn the fence off to make sure that is not causing any anomalies. Did that in this case as well and it made no difference.


　my first thought as well in similar situations




> Currently we don't have a permanently installed emergency generator (although santa brought us a propane generator, only a few months late for our date with Irene and a week of understanding how the old days were. that will get installed, although not likely before the spring).
> 
> I will be interested to see how the utility here works on NEV in rural settings. I certainly appreciate Mike Holt's serious take on the problem of NEV although I can see it is exacerbated by rural electrification and despite the benefit I now derive from our country's commitment to that plan I disagree completely with the economics of rural utility service at rates subsidized by those buying power in more concentrated demographics. I certainly don't blame the utilities for not being willing to almost literally reconstruct their services and grids at great expense to the bulk of customers to fix a problem that plagues a small number in no small part because of their remote location. (which means to say the manifestation of NEV as a serious problem vs. the question of whether it exists as noticeable or measurable phenomenon for a larger number of people).
> 
> ...


　welp, any time you'd like to start a thread on poco's sucking up to the green machine, stimulus $$$, or ignoring the infastructure falling down around them i'm there.....
　
personally, i think they're _not_ going to assume any cupability, and refer you to a stray V guy at best.....　
　




> as far as an equipotential grid, that is an extensive amount of work to water a few animals. Although being a curious guy (that's what everybody says about me - is that a compliment?), I'm interested whether a rudimentary and effective grid could be created in non slab situations by burying garage mess bonded to the neutral or whether it is too light or would corrode too quickly. Anyone have any experience? But before I'd go through that I could put in a small hot water heater and just dispense hot water or put a physical not metal agitator in the water run by an electric motor that was not in the tank.
> 
> As a background question, the link in a post above to the canadian site suggests that the manufacturer of "tingle" isolaters up there stopped making them for lack of demand. It sounded like those were a pretty good solution and might cost less than a grand to install.


　
I'm thinking it's addressing sympthoms, not causitive source....



> A good deal of the expense involved in installing those was separating grounds and neutral and then I believe the operation of this isolater was to provide a self closing connection between ground and neutral when maybe a certain voltage was acheived. Kind of like a scaled down version of a surge suppressor.
> 
> Is there anybody still making these in the states? Sounds like Mike HOlt's suggestion from the video, at least for a signficant ag installation, was for a second transformer. That seemed like it would be significnatly more expensive although it's funny how folks talk about these technologies without just coming out and saying how much they cost. And I don't know how this extra transformer affects the desired safety aspect of having the bonded neutral and ground.
> 
> Nough said. if you read to here, you like this kind of punishment


 
　oh, we_ luuurve_ this here

Ok, i'm going to go out on a limb, and more than likely my fellow posters will come in and clean it up for me, or dismiss me as hackamungo Steve*


my understanding is, you've multiple earthed Noodles , and the only recent change is the livestock was moved (is this correct)

you should be aware that multiple noodles will transmit a return path bettween them, and back to the serving xformer

the earth , despite the nec's insistance, _can _be a return path , dependent on solubility and acidity

So the best plan i can forward is to rethink this down to _one_ path only. This is where one really needs to visulize the circuit btw


*Move your MBJ to the pole. If this is your pole you'll not need permission, if it poco you probably will

Create an OH plan where the only triplex is to your pole, and all out seperates Noodle and Ground

Ground @ the Pole MBJ, send quadriplex form there on out, keep N & G seperated at every mast, meter, panel & subpanel

I'll don my asbestos suit for the ensuing 'help' i'm going to harvest from this post...

~CS~


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## hardworkingstiff (Jan 22, 2007)

chicken steve said:


> *Move your MBJ to the pole. If this is your pole you'll not need permission, if it poco you probably will


If there is voltage coming in on the PoCo grounded conductor, this won't take care of the issue. 

If the ground around the watering trough is a good enough path back to the PoCo system then you must get the potential of this ground and the electrical system ground (not the grounded conductor) at the same potential.


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## frenchelectrican (Mar 15, 2007)

Dennis .,

I was reading this thread and for the OP's situation and I am not sure if there is a item called netural blocker or sorta of item I called netural isolatator device and I have see it used on few farms with single phase services but triphase are not too bad afaik.

I think Ronk or Milbank did make that device.

Merci,
Marc


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## Dennis Alwon (May 9, 2009)

frenchelectrican said:


> Dennis .,
> 
> I was reading this thread and for the OP's situation and I am not sure if there is a item called netural blocker or sorta of item I called netural isolatator device and I have see it used on few farms with single phase services but triphase are not too bad afaik.
> 
> ...



Mike Holt talks about them (neutral isolators) in the video. It is a bit long winded (the video) but very informative.


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## Dennis Alwon (May 9, 2009)

He also mentions dual bushing transformer that are used throughout California. MH says he has never heard of a problem with stray voltage out there because of these tranies.


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## archibald tuttle (Dec 30, 2011)

joethemechanic said:


> Put the heaters on the *ungrounded* side of an isolation transformer. Then there will be no neutral. Do not bond anything or carry your ground from the rest of the system. Run a ground to all your heaters to a completely separably derived ground rod/rods 50 feet or more from your service grounding rods (close to the salty pizzed soaked highly conductive place where the cattle stand to drink is a good place). But there will be no neutral, and no neutral-ground bond on the heater circuit.
> 
> Screw if it's code or not.
> 
> I've stood barefoot and put the phase wire to my tongue to prove this one.


i assume by definition that the ungrounded side is the secondary although maybe if the transformer isn't a step up or down it couild theoretically have a primary/secondary function in both directions?

So if I'm thinking this through correctly, what you are saying about the tongue bit (I think the guy who came up with GFI's had a similar emperical approach) is with an isolation transformer the only shock hazard is between the two conductors and there is not a shock hazard to earth - except that you are looking for a separate ground for the heater? That would seem to indicate that there has to be some potential between this current and earth.

It would seem that bonding around an isolation transformer would defeat the purpose. 

On the other hand, if I'm think correctly the isolation transformer could power a GFI so shock hazard from some failure at the implement in use could be reduced.

Brian


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## archibald tuttle (Dec 30, 2011)

*is floor mesh suitable*



joethemechanic said:


> BTW,
> 
> Don't get locked into thinking of the equipotential grid in _concrete_ means "portland concrete" with aggregate.
> 
> ...


haven't heard what anyone thinks is a heavy enough mesh to be effective and to last long enough to make the project worthwhile. I'm still favoring isolation of the problem protem but folks with larger animal operations on some farm threads might be interested..

is the lime to counteract uric acid to prevent corrosion?


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## chicken steve (Mar 22, 2011)

while Joe's innovative approach may take the NEV out of the equation, it's only going to address it at the point of useage Brian. What i propose is an _entire _isolation scenario

one more Q, do you have an artesian well, or are you on a municipal water supply?

~CS~


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## archibald tuttle (Dec 30, 2011)

Dennis Alwon said:


> You also need to make it a voltage gradient ramp. If the animal steps from 7 volts to this grounded or bonded surface then they won't come in either.


Dennis,

get the concept although I think they are probably less sensitive foot to foot than foot to mouth, esp. while walking because they don't have all feet down and by definition they can't have all four down for ground vs. the equipotential plane.

that said, can't tell quite what the construction details to accomplish the gradient are from the picture.

brian


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## archibald tuttle (Dec 30, 2011)

*why dint i know you guys last year*



chicken steve said:


> it's always the first or last splice......


i could have saved a lot of time if I had looked at the last one first - although it was the one I had done with new burndy and noalox, on the other hand as i think about it dissimlar metals wins every time, so the aluminum to aluminum splices didn't give up - but maybe its just hewing to the principle about the last splice.

how did you know that, and should I have reasoned that the last splice gets the added resistances of all the splices, but I thought it was the current, which would be equal through out the circuit - no - that actually worked on the splice.

of course once it starts to degrade then the splice is a load unto itself and keeps getting worse, but why is it the first or last one?

curious in exeter


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## chicken steve (Mar 22, 2011)

It's just a Murphy's law thing Brian, when i have customers who explain that _'something let go'_ in their circuitry i usually tell them i don't have x-ray eyes, and that it might take 5 minutes or 5 hours to find.....~CS~


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## archibald tuttle (Dec 30, 2011)

chicken steve said:


> my understanding is, you've multiple earthed Noodles , and the only recent change is the livestock was moved (is this correct)
> 
> you should be aware that multiple noodles will transmit a return path bettween them, and back to the serving xformer
> 
> ...


so if I am a little hazy on this, are you suggesting that multiple noodles create multiple equipotential or gradiant voltage planes around them, i.e if the earth is a return path and the NEV potential at your location is 4 volts then you ought to be able to find a potential between the ground by your noodle and the ground closer to the substation?

If anything I would think this would help vis-a-vis the livestock. i get the current takes all paths relative to resistance so they would still be a path but the potential would be less.

put a different way, i assume that if I were to disconnect the ground wire from one of the noodles and put an ammeter in line I would see some amount of current flowing - probably small but some. so this is why some people seem to address the problem by putting in lots of ground rods although that still doesn't defeat the potential and the ALL PATHS RELATIVE TO RESISTANCE, maybe enough of them would succeed in actually lowering the potential a bit.

My guess is that I must always have had some potential but that some condition on my side or the POCO side has boosted it up enough this year to cause the livestock reaction. The only thing I've found so far in my research of every service on the farm is that the grounding clamp on one of the services (not the closest one implicated in this problem) is broken.

this is the service that feeds the 700 foot run. (however that serves a people barn, never had the animals out there).

So just to perplex my mind, I'm getting the standard 4 volt NEV at that service, same as the other service but chasing out this 700 foot run, there is a juntion in a meter trough (I'm hoping to eventually get the poco to serve that load more directly and when I put up new poles last year while I had the wire down and was searching for the source of (infinite) neutral impedance I replaced the first couple hundred feet with underground conduit and double ought copper to a meter trough but repowered that out of the current service pro tem. So I'm 4 volts at the service but at this new meter trough about 200 feet out on really good copper I'm down to 2.5 NEV. No idea what that means but I tested repeatedly and could not get a similar reading even though they are only 200 feet apart and I just don't understand how it could get better going further into my side of the service. Then 700 feet of #6 aluminum triplex later (with several (maybe 3 or 4) burndied splices on the neutral all of which were cleaned and respliced last year) I'm up to 7 V NEV at the service. But that seems about sensible with the voltage loss on that run because I'm seeing about a 4 volt drop off on the hot to neutral (or should i say phase to neutral was is really proper terminology here) voltage from the service entry at the residence to the this subpanel 900 feet away.

OF course there is, as I pointed out a good ground rod out there and there is one at the pole that supplies all the services. Protem I'm going to fix the broken grounding connector and see if that changes things although I'm now interested in the merits your proposal to have one ground rod at service pole and quadriplex from there although that is a tall order for all the changing I'd have to do.

So, I'm also back to the question of, while I'm monitoring/resolving the larger question what benefit from using the isolation transformer approach and independent ground vs. my current approach which is just to make an independent ground for the tank heater which is operating on a ground fault.

brian

PS - once i get various projects that were supposed to be done in october out of the way (thank god for global warming) I'll be glad to be back and start all those threads about the pocos in bed with the greens and the government and hanging us out to dry.


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## chicken steve (Mar 22, 2011)

archibald tuttle said:


> > so if I am a little hazy on this, are you suggesting that multiple noodles create multiple equipotential or gradiant voltage planes around them, i.e if the earth is a return path and the NEV potential at your location is 4 volts then you ought to be able to find a potential between the ground by your noodle and the ground closer to the substation?
> >
> > If anything I would think this would help vis-a-vis the livestock. i get the current takes all paths relative to resistance so they would still be a path but the potential would be less.
> 
> ...


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## joethemechanic (Sep 21, 2011)

archibald tuttle said:


> haven't heard what anyone thinks is a heavy enough mess to be effective and to last long enough to make the project worthwhile. I'm still favoring isolation of the problem protem but folks with larger animal operations on some farm threads might be interested..
> 
> is the lime to counteract uric acid to prevent corrosion?


No, the lime makes the soil pack very hard, it will prevent the animals from displacing the soil that is above your grid. Strictly a structural factor, nothing to do with conductivity or chemical corrosion.

Next time you have a little mud hole that almost never dries up, dump some lime in the hole and rake it into the soil. It'll not only dry it up, but it will pack hard as hell.

And I am sorry, yes I meant the ungrounded secondary (heater load side) of the isolation trans.

How big of a heater load are we talking?


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## joethemechanic (Sep 21, 2011)

The heavy equipment isn't required, nothing magical happening there. They just are using it to speed up the operation. A farmer will most likely have a hoe or a tiller of some kind and the end result is just as good


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## joethemechanic (Sep 21, 2011)

Road project in Ethiopia


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## retiredibew (Dec 28, 2011)

have to agree with chicken steve, i have ran into this problem many times the most common cause is driving ground rods instead of using 4 wires between multiple sub panels. we are talking about only one service transformer, correct?


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## hardworkingstiff (Jan 22, 2007)

retiredibew said:


> i have ran into this problem many times the most common cause is driving ground rods instead of using 4 wires between multiple sub panels. we are talking about only one service transformer, correct?


The one time I ran into this, there was one transformer, one connection of the GEC to the neutral in the service panel, no subpanels. Ground to water (ICWW) had a 1.5V potential. When the main was turned off the potential was still there. When the PoCo neutral was lifted at the meterbase the potential difference went away. 

It was obviously coming in from the PoCo system. I believe that this is inherent in the way our distribution system works, and unless you can get the PoCo to go to a separate ground and neutral distribution system we will have to live with it (but from what I read, for stabilization reasons we need the neutral grounded to earth potential).


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## Semi-Ret Electrician (Nov 10, 2011)

The NEV problem is really serious in Wisconcin and at least one dairy farmer sued and won $1.2M from the POCO after trying to fix it themselves.

Livestock go nuts over 1 ma. so a typical GFCI is not good enough.

More ground rods make matters worse, if the problem is coming from your neighbors, which is easily proved by turning off your main for a minute, unless your grounding system or the POCO's is faulty.

Just a thought, how about if you heat the water in an insulated residential water heater in a shed and use a circulating pump to the watering troughs? Might be cheaper than equipotential grids. 

But won't solve all the other NEV problems.


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## tates1882 (Sep 3, 2010)

Heres a thread http://www.electriciantalk.com/f2/stray-voltage-current-30575/.


I come across the op's situation all the time my bet is that there is a neutral and ground bonded some where in the system down stream from the main OCD and there is a three wire feeder (H/H/N) going to a disco/sub panel with a ground rod. Causeing the situation. Just my thoughts with a quick skim of the thread.


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## hardworkingstiff (Jan 22, 2007)

Semi-Ret Electrician said:


> More ground rods make matters worse, if the problem is coming from your neighbors, which is easily proved by turning off your main for a minute, unless your grounding system or the POCO's is faulty.


OK, so you turn off the main and the voltage doesn't go away, then what's the problem?

This type of situation can be very difficult to diagnose.

As far as more ground rods making it worse, why then are we required to install additional ground rods at a sub fed structure? If you are correct in additional ground rods are making things worse, then we would not have to do this.

Remember, the OP does not have an issue with his neutral, he has the issue that his ground (from the service) is at a different potential than the earth around the equipment that is being fed (and bonded to the service ground). This type of problem is inherent in the type of distribution system we have, and that is why we are required to continue to re-ground as we feed sub structures. We need to make sure the ground potential of what we are feeding is at the same potential as our service ground. 

I don't understand how you can say more ground rods make matters worse. Please explain. (If you are talking about additional N/G connections, I don't believe anyone has suggested that).


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## Semi-Ret Electrician (Nov 10, 2011)

If there is eath return between a fault and the POCO rod and you're standing barefoot touching a ground rod you have what is called a step potential.

Even a few volts between your feet can be very dangerous.

I've heard of people getting electrocuted stepping off towers or running over energized ground during lightning storms. 

If you turn off your main and the problem persists stick a screwdriver in the ground attach a 50 ft wire to it with a voltmeter and start walking around taking measurements by sticking the probe in the earth. If the reading gets stronger, you're going in the right direction.


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## archibald tuttle (Dec 30, 2011)

*SENsitivity*



chicken steve said:


> archibald tuttle said:
> 
> 
> > well what i see on most farms is explained as <MEN> Brian>
> ...


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## archibald tuttle (Dec 30, 2011)

*heater load, loaders, etc*



joethemechanic said:


> No, the lime makes the soil pack very hard, it will prevent the animals from displacing the soil that is above your grid. Strictly a structural factor, nothing to do with conductivity or chemical corrosion.
> 
> Next time you have a little mud hole that almost never dries up, dump some lime in the hole and rake it into the soil. It'll not only dry it up, but it will pack hard as hell.
> 
> ...


Joe, I'm down with the notion that one could construct equipotential grid short of slab pouring and you kind of work with the equipment you've got. Loader, rototiller, excavator or all three.

Still trying to figure out what would constitute a heavy enough/dense enough mesh to get the job done). I think standard floor mesh is 6" on center and maybe an eight inch but I think they actually spec it by wire size (maybe convenient for our purposes) and I think it is an 8.

I'm going to have get some lime and try out the artificial limestone approach to solidifying mucky areas. sounds kind of like cement without the expense of cooking the limestone.

The heater is 1000 W. Generally in most agricultural operations the most I have seen is a 1500 W which is obvious deference to your average 15 or 20 amp circuit rather than particularly revealing about what loads would be appropriate to actually get the job done.

But 1500W will keep a pretty big tank open and we use a slightly more modest size.


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## archibald tuttle (Dec 30, 2011)

*thank god for the semi-retired*



retiredibew said:


> have to agree with chicken steve, i have ran into this problem many times the most common cause is driving ground rods instead of using 4 wires between multiple sub panels. we are talking about only one service transformer, correct?


so, this is actually a four wire service from the breaker panel (well really 3 wire because it is 120 but metaphorically speaking it has an independent insulated ground running in the conduit from the house to the barn and I'm getting essentially the same NEV reading at the panel at the house as at the point of usage so I'm assuming that in my case although this can be a prevalent cause it is not the cause here. If multiple ground rods are actually introducing the NEV (or augmenting) from elsewhere (but I assume somewhere near, maybe even some other part of our install, I won't start squawking to the power company until I'm convinced that I show the same NEV everywhere on the farm and it is on the same on the poco neutral side when that is disconnected.), it is being introduced at the main service panel. But, as I mentioned to chicken steve, there are several main panels and several main bonding jumpers on the farm all served off the same transformer.


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## archibald tuttle (Dec 30, 2011)

hardworkingstiff said:


> The one time I ran into this, there was one transformer, one connection of the GEC to the neutral in the service panel, no subpanels. Ground to water (ICWW) had a 1.5V potential. When the main was turned off the potential was still there. When the PoCo neutral was lifted at the meterbase the potential difference went away.
> 
> It was obviously coming in from the PoCo system. I believe that this is inherent in the way our distribution system works, and unless you can get the PoCo to go to a separate ground and neutral distribution system we will have to live with it (but from what I read, for stabilization reasons we need the neutral grounded to earth potential).


Did you see the link that chicken steve posted? It seems to say that there is an alternative to this multiple earth grounding. I still can't figure out because the poster does not list the disadvantages of SEN (although he is all over the disadvantages of MEN) if SEN would require additional wires or additional insulated wires so an obvious disadvantage would be cost of replacing essentially our entire grid. nor does he indicate whether a hybrid system could be operated if upgrades were to phase in (sorry) an SENN approach. of course his post wasn't intended to be a proposed implementation, but I think that one has to understand the pragmatics of undertaking the change before become a champion of SEN.

That said, one very attractive feature was that is sounded like ground fault detection was much improved meaning maybe SEN could be implemented without major rewiring but with new more accurate fault sensing equipment that substitutes for the safety now thought to be provided by the MEN approach.

obviously I more or less agree with you that we are stuck with some NEV for the time being as the legacy of our legacy grid. I'm trying to figure out what constitutes exceptional NEV that requires remediation or indicates something worse than usual on the poco neutral. obviously, just according to the theory of origin, being in a rural area and likely further from the substation (although I haven't really looked into where our service is really originating although once I go over my own 'grid' this week I'm going to get in touch with a friend who's a lineman for the poco and start to work from that end) we are subject to a higher value for NEV by design (or lack thereof).


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## archibald tuttle (Dec 30, 2011)

*now you're thinkin like my crew BSBV*



Semi-Ret Electrician said:


> Just a thought, how about if you heat the water in an insulated residential water heater in a shed and use a circulating pump to the watering troughs? Might be cheaper than equipotential grids.
> 
> But won't solve all the other NEV problems.


In this world of acronyms, you perhaps have not encounter BSBV, which stands for the Bastard Sons of Bob Vila. 

in our case it is 'this old farm'.

just discussing with our plumtrician consultant the possibility of putting an automotive block heater underneath the tank and running it as a separate circuit (of water that is) through maybe some pex pipe and fill it with an antifreeze solution and put several curls of the pipe into the trough and then back down to the block heater.

Of course this still brings up the question of whether to ground that heater in which case I would be bringing the NEV that far and then whether there would be any leakage (I imagine there is no such thing as none but let's say any measurable leakage) of that potential from the antifreeze solution through the pex to the water in the trough.

But so far I'm still not talked out of our present approach which is to ground the heater independently of the bonded ground. 

thanks for applying creativity to this question.

one thing that occurs to me relative to the dairy farm problems is how exactly does a milking machine work, i've milked by hand but never with a machine. Assuming the problem is that the machine is electrical in some respect that is close enough to the cow to create a circuit through the udder (mike holt says uterus but that's another story) to the ground where the cow is standing.

I'm assuing that the function could probably be accomplish by air or an air motor so that the electricity could be consumed at a compressor. There maybe other problems that the NEW could be on the cattle stanchions or other issues that this would not solve but Mike Holt seems to imply (and there is some agreement in the audience who are more familiar with ag siutations because the corrected him on the udder/uterus controversy) that the source of unwanted potential is the milking machine.

So I often use air tools if I have long transmission to remote parts of the farm and don't want to hurt electrical tools by having them on very long cords. If my air transmission is insufficient, the tools don't perform well but it doesn't hurt them. 

It would seem to me that you ought to be able to perform constriction and stripping functions related to milking with air instead of electricity. that may be a gross oversimplification. sometime when i got nothing better to do i'll visit a dairy to actually see one of these machines. well i've seen one, but to get a closer look.

if you are aware of the mechanisms of NEV transmission in these wisconsin cases, i'd be interested.

brian


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## archibald tuttle (Dec 30, 2011)

hardworkingstiff said:


> OK, so you turn off the main and the voltage doesn't go away, then what's the problem?
> 
> This type of situation can be very difficult to diagnose.
> 
> ...


here i would have to dissent modestly which is to say, just because we "have to" do it doesn't mean that it doesn't make matters worse. It seems that we are dealing here with risk analysis. Additional ground rods provide a margin of safety for certain circumstances but add a margin of danger in other circumstances.

One supposes that the code might have taken such comparative risk into account when arriving at the favored required approach, but I think it is equally likely the the status quo and prevailing factors, habits and prejudicies are instantiated in the code as that it is truly better practice in some objective way. I'm not even 100% clear from the technical discussions here whether the proliferation of ground rods, given the type of system we have adopted which as you recognized will exhibit a certain degree of NEV by design, is like the question of vaccination where if you do differently on your side of the meter you are causing a hazard to other members of the public or the poco linesman. 

Especially if you go to single ground rod at the entry of service to your property or at the last service pole with a single MBJ andfour wire distribution from there.

Of course I haven't quite figured out the reasoning as to what harm these additional grounds may pose and to an extent even the additional MBJ. If you have an MBJ at the first pole what is the difference in adding more, kind of the same question I have relative to ground rods. My situation is a wire service panel and its MBJ which is not even a hundred feet from the last pole and then 4 wire from there about 350 feet to this barn and I read the same NEV there as up front.

And BTW for those following along at home, the interesting additional result that seems to bear out some of what semi-retired and chicken steve are saying about the down side of additional ground rods.

I'm at 5 volts NEV this morning at the panel and at a water trough for the donkeys who have smaller feet and don't seem to be bothered by the effect with the heater still grounded through a 3 wire plug. Unplug the ground prong on that trough and NEV disappears, I mean water to earth is 0. But at the trough with the ground connected instead to its own ground rod, we're at .7. That's a lot less and it does appear that we are getting the horses to drink but I can only believe logically that that ground round is importing stray voltage. Is it some portion of the NEV voltage showing up from the ground rods up front? maybe. OR is it voltage from some distant ground fault or . . .? 

talk amongst yourselves because I need a good deal more conversion to wrap my mind around the concept of parallel paths for the NEV. If you have most NEV showing up at your incoming neutral from the poco i'm not sure how additional grounds actually introduce the NEV but sure seems like a possibility relative to the most recent testing described above. 

Taken independently, in theory multiple ground rods seem to operate somewhat like a disparate version of the equipotential grid simultaneously coupled with the notion of many less resistive pathes to earth. But just as the equipotential grid needs a gradiant maybe even though this ground rod is some 300 feet away from the service panel ground rod it is on the gradient from the tine equipotential plane established by the ground rod itself ergo it is exhibiting .7 of the 5 volts at the service panel ground.

Cowrong me if i'm wrecked here, just blowing some smoke trying to figure out what to infer is happening.

One thing I do get is if you had an equipotential grid that say came into contact with metal underground utility of some sort then the NEV potential would be transmitted wherever those utilities go. But if your system exhibits equal NEV distributed from the Poco and not relative to problems on your private side grid I'm not sure how the extra ground rods cause NEV problems except where you have, as I have grounds in this one case that are isolated from neutral.

I am clear (although maybe wrong here but I don't think so) that they could provide a dangerous path to a ground fault current in the area that was not interrupted. So the risk issue there is how prevalent are such faults and how unlikely to be detected by means other than harmful accidents.

grist for the mill. 3.5 more days of christmas to sort this out.

brian


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## archibald tuttle (Dec 30, 2011)

Semi-Ret Electrician said:


> If you turn off your main and the problem persists stick a screwdriver in the ground attach a 50 ft wire to it with a voltmeter and start walking around taking measurements by sticking the probe in the earth. If the reading gets stronger, you're going in the right direction.


i like this approach because it seems imperical. it also supports the issue of problems with additional ground rods, esp. depending on their direction relative to this current getting higher.

we're basically talking about all the earth between a voltage drop and the substation turned into a gradient plane as envisioned more discretely relative to taperoff from a constructed equipotential plane. and, of course between is not a geographical but electrical concept here so were not talking as the crow flies necessarily.

but I'm a little confused on method and approach. so i shut off the mains. still read about the same NEV. do I stick the screwdriver in the ground near the ground rod for the service I just shut off the mains on? That's what it sounds like. now we're looking for a differential in the earth between two points?

just checking.

brian


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## Semi-Ret Electrician (Nov 10, 2011)

Brian, the screwdriver measurement is called a remote ground. It's purpose is to try and track down the source of NEV.

You set it away from anything electrical and try to see where the strongest voltage is coming from.

Don't try to prove anything just make a map and record your findings.

Record time of day, distance to the reference point , what's running, is your main on? etc.etc.

The power co. expects more voltage near their ground rods because more than half of the unbalanced neutral current has been seen returning to the utility company via the earth.

If your neighbors have livestock they may want to participate in this study because if their herds are getting shocked their milk production could drop, refuse to enter stalls or drink.

An analog voltmeter seems to work best and many folks keep one set up to either record or just glance at, especially during peak usage or when the animals are behaving funny.

Keep us posted and good luck!


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## joethemechanic (Sep 21, 2011)

How many of these heaters do you have that are a problem?


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## joethemechanic (Sep 21, 2011)

I was thinking this, with no N-G bond anywhere on the secondary (load) side and anything that animals have the possibility of coming in contact with grounded locally.

The only problem would be that if there was a phase to case fault on the secondary, there would be no path to blow the overload protection.


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## joethemechanic (Sep 21, 2011)

```````


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## joethemechanic (Sep 21, 2011)

Or This. And just dead end the service grounding conductor at the isolation trans


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## joethemechanic (Sep 21, 2011)

One like this


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## hardworkingstiff (Jan 22, 2007)

joethemechanic said:


> Or This. And just dead end the service grounding conductor at the isolation trans


Or, just drop out the transformer and reference the circuit ground to earth. 

Really, an attempt should be made to see if this is coming from the line or load side of the PoCo transformer. If it's on the load side (a neighbor on the same transformer) then if you got the PoCo to pull the fuse feeding this transformer, then you would know if the problem is coming from the PoCo distribution or from the transformer secondaries.


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## joethemechanic (Sep 21, 2011)

Screw the electric altogether and heat the water with LP gas. It's probably cheaper anyway.


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## frenchelectrican (Mar 15, 2007)

joethemechanic said:


> Screw the electric altogether and heat the water with LP gas. It's probably cheaper anyway.


 
Joe .,

Ya work on alot of engine driven equiment so you have just hit the nail on that one and yeah I have see gaz fired " block " heater.

That should take care of all the stray voltage issue on livestock.

Merci,
Marc


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## joethemechanic (Sep 21, 2011)

frenchelectrican said:


> Joe .,
> 
> Ya work on alot of engine driven equiment so you have just hit the nail on that one and yeah I have see gaz fired " block " heater.
> 
> ...


Marc

Speaking of non-electrical solutions how about these?


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## frenchelectrican (Mar 15, 2007)

joethemechanic said:


> Marc
> 
> Speaking of non - electrical solutions how about these?


Yepper we have them in few spots Marine and Avion ( Aircraft ) used them a bit.

Merci,
Marc


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## joethemechanic (Sep 21, 2011)

An even greener solution.

My grandfather's family was from Alsace Lorraine. When I was a kid, he always use to tell me about how in Alsace they built double wall buildings and filled the space in-between the walls with manure to protect the contents from freezing.

Say he surrounds 3 sides of his tank with manure. For that matter, how about a tank set into the ground, and surrounded on all sides with manure?

Best part is, the manure is free


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## frenchelectrican (Mar 15, 2007)

joethemechanic said:


> An even greener solution.
> 
> My grandfather's family was from Alsace Lorraine. When I was a kid, he always use to tell me about how in Alsace they built double wall buildings and filled the space in-between the walls with manure to protect the contents from freezing.
> 
> ...


Joe.,

I have heard that story few time.

But even better.,, terra is best bet.

Let not get too far off topic in here just remember that we have to help the OP to slove the issue there and AFAIK, I do not know if he got it or not.

Merci,
Marc


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## joethemechanic (Sep 21, 2011)

Something like this


http://www.enviroharvest.ca/images/1500_btu.jpg


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## frenchelectrican (Mar 15, 2007)

Joe.,

Oui ., that will work and I did catch the rating of that one is 35,000 BTU that sucker will keep the tank very warm no question asked but only one major drawback is if you have strong windy day it will flameout on that so that is one of few drawback plus tank size as well.

Merci,
Marc


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## joethemechanic (Sep 21, 2011)

```````


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## joethemechanic (Sep 21, 2011)

frenchelectrican said:


> one major drawback is if you have strong windy day it will flameout on that so that is one of few drawback plus tank size as well.
> 
> Merci,
> Marc



How long a period will this heater tank have to go unattended?

Remember water is the 2nd best thermal mass (thermal storage) that there is. So a large tank of water will hold temp above freezing for quite some time.


Water is 2nd best thermal mass by weight. Hydrogen is the best thermal mass by weight, but due to low weight, it is impractical.


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## frenchelectrican (Mar 15, 2007)

joethemechanic said:


> How long a period will this heater tank have to go unattended?


 
That is a megabuck question there but it boil down to the tank size and the firing cycling in the heater Just remember this heater run in vapour mode so with super cold weather it will affect the performace.

with 8KG ( simair to your 20 pound tanks ) bottle they will last about half day or less

so the best thing you can is lug a 45 KG ( 100 pound ) tank that will last a while. ( up to few days the most )

Merci,
Marc


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## joethemechanic (Sep 21, 2011)

frenchelectrican said:


> That is a megabuck question there but it boil down to the tank size and the firing cycling in the heater Just remember this heater run in vapour mode so with super cold weather it will affect the performace.
> 
> with 8KG ( simair to your 20 pound tanks ) bottle they will last about half day or less
> 
> ...


Unless he manifolds a couple of tanks together to gain storage capacity and increase vaporization rate.

For Example,

Five, 20 pound tanks will have a higher vaporization rate than one, 100 pound tank due to increased surface area


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## joethemechanic (Sep 21, 2011)

joethemechanic said:


> Unless he manifolds a couple of tanks together to gain storage capacity and increase vaporization rate.
> 
> For Example,
> 
> Five, 20 pound tanks will have a higher vaporization rate than one, 100 pound tank due to increased surface area


Voir, l'esprit allemand est très très intelligent ha ha ha


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## hardworkingstiff (Jan 22, 2007)

joethemechanic said:


> An even greener solution.
> 
> My grandfather's family was from Alsace Lorraine. When I was a kid, he always use to tell me about how in Alsace they built double wall buildings and filled the space in-between the walls with manure to protect the contents from freezing.
> 
> ...


Man, that just stinks! :laughing::laughing:


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## archibald tuttle (Dec 30, 2011)

*i think that is what i have done . . .*



hardworkingstiff said:


> Or, just drop out the transformer and reference the circuit ground to earth.


I'm trying to figure out what safety I gain by isolation. maybe in JTMs second diagram where one leg of the secondary is grounded this would afford approximately the same protection in event of a phase fault as traditional grounding to the bonded service but would reduce exposure to NEV to the voltage drop created on the secondary side of the transformer which is to say virtually 0 assuming the transformer is located close to the tank heater load. with the exception that the ground rod appears to be channeling some of the ambient NEV as with the heater grounded but otherwise unplugged I show .7 volts (an order of magnitude reduction for the problem but still a significant amount). 

Without the grounding and with the heater plugged in I show 0.

So this boils down to how much do I trust GFI technology. silly thought, what if i just put 2 GFIs in line, what is the chance of both of them failing on at once and then forget about the ground. I mean at 10 bucks a pop . . . or are there more robust GFIs that would split the difference in cost. (more on that under propane responses.)

As to JTMs second diagram, I'm hazy on how you can just pin one leg of the secondary to ground without effecting a ground fault unless the transformer carries over a 'polarity???' from the poco/grid side. I have to try to imagine the sine wave for 120 phase to neutral to think about how this works. maybe somebody can walk me through that. 

But I do believe my current installation coordinates with your thought that I just install an independent ground. I have detached the equipment ground from the bonded ground network and made a separate and distinct ground (it is actually attached to the heater itself although JTMs diagram shows the grounding of the tank case. That may be a metaphor what with plastic tanks these days.)

brian


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## hardworkingstiff (Jan 22, 2007)

archibald tuttle said:


> But I do believe my current installation coordinates with your thought that I just install an independent ground.
> brian


Just to be clear, I hope I have not been interpreted as to saying the electrical circuit ground should be dropped. This is not what I've been saying.

Since you have a voltage potential between ground and the circuit ground, they must be referenced to each other. Not the neutral, the ground only. This is why in a sub fed panel in a separate structure you must drive ground rods and reference your ground wire (but not the neutral) to the local grounding system.

But, 1st you really need to determine where the voltage is coming from. If it's on premise, fix it. If it's from the PoCo system, well, not much you can do about it, just notify the PoCo and drive some ground rods. 

I'm still waiting for an explanation from anyone as to why driving ground rods and connecting the circuit ground to the local ground compounds the problem. Again, I'm not talking about the neutral, it remains isolated. More than one person has said that doing what I suggest makes the problem worse, I am seriously asking why? I need a scientific explanation please.


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## archibald tuttle (Dec 30, 2011)

joethemechanic said:


> An even greener solution.
> 
> My grandfather's family was from Alsace Lorraine. When I was a kid, he always use to tell me about how in Alsace they built double wall buildings and filled the space in-between the walls with manure to protect the contents from freezing.
> 
> ...


I have undertaken some measures along these lines, however they don't take cognizance of the frequent need to empty and clean the trough. needless to say the wife thinks that need is a little more frequent than the guy who has to make the heaters work without habituating the horses to give up drinking.

There is a good argument for a dual skinned tank with maybe four inches of insulation and insulated cover with a drinking hole that could mostly be kept open by the occasional visit by a horse or maybe could have an agitation paddle attached to the cover that could be turned by hand or spring wound so it could agitator a small motor. as long as the paddle weren't metal.

I suppose if this problem isn't easily resolved while chasing the NEV as general interest pursuit I could try to make one myself by getting two modestly concentric troughs and expanding foarm to place between them.

off to the internet to see if someone has done this already where their manufacturing experience may be worth more than my opportunity cost of doing it myself, especially vis-a-vis the tank itself, I could do some kind of a top and maybe even home made agitator.

brian


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## joethemechanic (Sep 21, 2011)

archibald tuttle said:


> I have undertaken some measures along these lines, however they don't take cognizance of the frequent need to empty and clean the trough. needless to say the wife thinks that need is a little more frequent than the guy who has to make the heaters work without habituating the horses to give up drinking.
> 
> There is a good argument for a dual skinned tank with maybe four inches of insulation and insulated cover with a drinking hole that could mostly be kept open by the occasional visit by a horse or maybe could have an agitation paddle attached to the cover that could be turned by hand or spring wound so it could agitator a small motor. as long as the paddle weren't metal.
> 
> ...


I was thinking of digging a big hole in the ground throwing some poo in the bottom, sitting the tank in on top of the poo, and then backfilling around the sides of the tank with more poo.

when you need to change the poo, just pull the tank out, and remove the spent poo with a backhoe

Poo isn't just insulation, the bio degradation taking place in poo produces a lot of heat.

As a kid I can remember digging into the manure pile with a loader during the winter. It was never really frozen all that thick, and inside it was steaming. In fact, that is what prompted my grandfather's stories about Alsace Lorraine


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## archibald tuttle (Dec 30, 2011)

question about the root causes of NEV. How does the effort to balance the 120 loads across the 240 coming from the transformer affect the current in the primary neutral? obviously you can reduce the current in neutral between the transformer and the service panels and subpanels by good balance so that alone could help the phenomenon on the load side and the line side up to the transformer, because if there is very little current on the neutral then the voltage drop would be negligible. 

I guess there is no such cure as this on singlephase power. is there less NEV problem on three phase primary power if use on the phases is balanced?

Three phase is 3/4 mile away and our road is non industrial so it will probably remain illusory as any solution toward our end but i'm interested to continue to learn more about this.

thanks


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## muck (Jun 30, 2008)

I worked on a marina once that had bubblers to keep the ice from forming.
Wouldn't a small piece of pvc in the bottom of tank hooked to a air source (ie: fish tank type) work the same?


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## archibald tuttle (Dec 30, 2011)

*all of that is true but . . .*



joethemechanic said:


> I was thinking of digging a big hole in the ground throwing some poo in the bottom, sitting the tank in on top of the poo, and then backfilling around the sides of the tank with more poo.
> 
> when you need to change the poo, just pull the tank out, and remove the spent poo with a backhoe
> 
> ...


. . . the issue I have is changing the water and cleaning the tank. The horese - i don't know about other stock - aren't great at not getting crap in the the water and although it is cold time of year you still get some biofilm building up in water and on tank and wife wants to empty it every couple weeks and clean it so that is going to be complicated for a buried install. She has compromised on installations for a single horse where we banked manure around the trough but that still needed a heater although not as big a one.

I'm thinking the next effort is going to be to find some concentric rubber/plastic tanks that will leave me about 4 " between and create a foam insulated tank that is still light and above ground. And then I'll maybe I'll sandwich a piece of foam insulation between a couple pieces of plywood cut to overlap the top of the trough and with a smaller hole for drinking, and that help keep clean but won't be too heavy to take off. Then we can experienment whether a smaller heater or no heater and agitation might actually keep this free.

In the meantime while on the old system still trying to figure out how much more risk I run with the separate ground and GFCI protection without the isolation transformer. And did you see my thought about adding another GFCI inline as protection against the failure of one?

Couldn't find any small propane fired heaters that seemed suited to the job.

Possibly could use small water heater of some sort, but would have to work on how to thermosiphon. If it was electric and the heater were grounded I imagine I'd be introducing the same problem except that the heater could be connected to the trough by nonconductive piping so it would only be the water that would transmit the potential. Obviously it is capable of doing that but do you thin such an installation with a remote piped electric heater might attenuate the potential somewhat.

thanks for all your ideas.

brian


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## joethemechanic (Sep 21, 2011)

archibald tuttle said:


> . . . the issue I have is changing the water and cleaning the tank. The horese - i don't know about other stock - aren't great at not getting crap in the the water and although it is cold time of year you still get some biofilm building up in water and on tank and wife wants to empty it every couple weeks and clean it so that is going to be complicated for a buried install. She has compromised on installations for a single horse where we banked manure around the trough but that still needed a heater although not as big a one.
> 
> I'm thinking the next effort is going to be to find some concentric rubber/plastic tanks that will leave me about 4 " between and create a foam insulated tank that is still light and above ground. And then I'll maybe I'll sandwich a piece of foam insulation between a couple pieces of plywood cut to overlap the top of the trough and with a smaller hole for drinking, and that help keep clean but won't be too heavy to take off. Then we can experienment whether a smaller heater or no heater and agitation might actually keep this free.
> 
> ...


Brian,

You don't think a propane fired heater like the one in the picture would work for you? I never looked into pricing. A 1,000 watt heater is roughly 3,400 BTU per hour of heat if it runs at 100% duty cycle.

To put that in perspective, Typical BTU content of LP gas is somewhere around 90,000 BTU per gallon.


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## Dennis Alwon (May 9, 2009)

Here is another option. You can use an insulated bubbler similar to what you see in fish tanks. The unit would not have a ground so the situation should be okay.

Also you can use a small recirculating pump that runs all the time and is located outside the trough. Much like a fountain that keeps the water moving.


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## muck (Jun 30, 2008)

Dennis,
Check out post 99 - beat ya too it - LOL
I do think a bubbler would work.
Could probably find some kind of heater to heat the air too.


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## Dennis Alwon (May 9, 2009)

muck said:


> Dennis,
> Check out post 99 - beat ya too it - LOL
> I do think a bubbler would work.
> Could probably find some kind of heater to heat the air too.


I must admit I miss a few post so I'm am glad someone else thought of it also-- :thumbsup: I think that is a viable option. I would prefer to find the source of the problem tho.


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## joethemechanic (Sep 21, 2011)

Hell, I want to build a Horse Poo digester and run a generator on poo gas. Then tell the POCO to keep their poor quality expensive power with grounding issues.


I love Poo power lmao


Can we get a government subsidy to build it?

It would also reduce poo gas emissions. (greenhouse gas)


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## muck (Jun 30, 2008)

I think putting the bubblers in would be cheap enough and give him some time to trace down the real problem.
At least the stock would be able to drink.


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## joethemechanic (Sep 21, 2011)

muck said:


> I think putting the bubblers in would be cheap enough and give him some time to trace down the real problem.
> At least the stock would be able to drink.



Sure, but you need an oilless compressed air source to provide air for the bubblers.

It isn't like you can just use any old compressor

Although you only need a couple of PSI to run a bubbler


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## Dennis Alwon (May 9, 2009)

I just realized the op is up in Connecticut-- a bubbler may not keep the water free. Heck I have seen the ocean freeze by the shoreline.


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## archibald tuttle (Dec 30, 2011)

*rock on*



muck said:


> I worked on a marina once that had bubblers to keep the ice from forming.
> Wouldn't a small piece of pvc in the bottom of tank hooked to a air source (ie: fish tank type) work the same?


of course. why didn't i think of that. because you did.

coupled with a better insulated trough that could be the answer.

this isn't a stock keeping forum so don't imagine everybody will be imitating my approach here and i will remain interested in NEV and this electrician talk but non-electrical solution seems at hand. and when all is said and done i'll probably pay back within a couple seasons in electric savings.

brian


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## archibald tuttle (Dec 30, 2011)

*but . . .*



Dennis Alwon said:


> Here is another option. You can use an insulated bubbler similar to what you see in fish tanks. The unit would not have a ground so the situation should be okay.
> 
> Also you can use a small recirculating pump that runs all the time and is located outside the trough. Much like a fountain that keeps the water moving.


would the recirc pump if grounded not transmit some of the new to the water even if it was not in the trough? mike holt talks about people getting zapped by NEV in pools which I can only imagine mostly would come through recirc equipment for the pools.

maybe real small pumps are double insulated or something and don't have a ground? again, i'm more than willing to double up on GFIs. I reckon if the percentage chance of failure on for one of those is x then the percentage chance of two failing on is the inverse of x squared.

bsquared


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## archibald tuttle (Dec 30, 2011)

*maybe an aerator for a big fish tank?*



joethemechanic said:


> Sure, but you need an oilless compressed air source to provide air for the bubblers.
> 
> It isn't like you can just use any old compressor
> 
> Although you only need a couple of PSI to run a bubbler


i'm not an aquarium afficiando but I would think they probably have some pretty good sized aerators for big tanks. off to search the internet later tonite.


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## muck (Jun 30, 2008)

Dennis Alwon said:


> I just realized the op is up in Connecticut-- a bubbler may not keep the water free. Heck I have seen the ocean freeze by the shoreline.


Connecticut? OK - put a inline air heater in the system.:thumbup:


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## muck (Jun 30, 2008)

Google - marine bubbler ice prevention

and

inline air heaters

Hope this helps


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## joethemechanic (Sep 21, 2011)

I still think this unit is the way to go


http://www.powertogo.ca/images/5_7000 _btu.jpg

5000 btu hour capacity (by comparison your 1000 watt heater is 3400 btu hour)


3.7 oz/hr propane consumption (that is about a week running flat out on a bbq grill tank)

All self contained and totally off the grid



http://www.powertogo.ca/engine_heaters.htm


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## Dennis Alwon (May 9, 2009)

muck said:


> Connecticut? .:thumbup:


Actually Rhode Island-- I should never trust my memory.


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## Semi-Ret Electrician (Nov 10, 2011)

hardworkingstiff said:


> OK, so you turn off the main and the voltage doesn't go away, then what's the problem?
> 
> This type of situation can be very difficult to diagnose.
> 
> ...


If the NEV problem doesn't originate from his service and he is halfway between the source (POCO ground rod) and a 120V fault (say his neighbors defective water heater or 3 wire range or dryer) he will be standing on 60V of energized soil (relative to the POC or his neighbor).
An equipotential plane just gets all the cows and people to stand on the same 60V section, so they don't get shocked.

In the case above a bunch of ground rods become a bunch of collectors of earth return current. 

The last place you want to be in a lightning storm is under a large tree in a flat pasture. The tree is just a ground rod going 80 ft into the air, a huge collector. If it gets hit, you better be standing on one foot.

Three wire feeds to barns (2 hots and a ground) are no longer permitted because, according to EPRI, a large percentage of the unbalanced neutral current will return via the grounding system and earth to the ground rod at the pole.


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## hardworkingstiff (Jan 22, 2007)

Semi-Ret Electrician said:


> If the NEV problem doesn't originate from his service and he is halfway between the source (POCO ground rod) and a 120V fault (say his neighbors defective water heater or 3 wire range or dryer) he will be standing on 60V of energized soil (relative to the POC or his neighbor).
> An equipotential plane just gets all the cows and people to stand on the same 60V section, so they don't get shocked.
> 
> In the case above a bunch of ground rods become a bunch of collectors of earth return current.
> ...


Gotcha, but you are assuming this is a fault condition at a served structure (house or barn or ...). This also could be from a neutral (with a degrading connection) on the PoCo distribution system.

Electrical circuit grounds and the ground of the earth must be at the same potential. So when you install your equipotential plane, you will be in effect connecting the electrical circuit ground to the earth ground potential at the location served. If you don't, the horses will still get shocked. You want to do it with an equipotential plane and I think you can succeed with some grounding.


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## tates1882 (Sep 3, 2010)

archibald tuttle said:


> would the recirc pump if grounded not transmit some of the new to the water even if it was not in the trough? mike holt talks about people getting zapped by NEV in pools which I can only imagine mostly would come through recirc equipment for the pools.
> 
> maybe real small pumps are double insulated or something and don't have a ground? again, i'm more than willing to double up on GFIs. I reckon if the percentage chance of failure on for one of those is x then the percentage chance of two failing on is the inverse of x squared.
> 
> bsquared


You could try these.. http://www.miraco.com/. Both my families have farms and neither one has any electric waters. These kind or the black ones that have round balls.


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## archibald tuttle (Dec 30, 2011)

tates1882 said:


> You could try these.. http://www.miraco.com/.  Both my families have farms and neither one has any electric waters. These kind or the black ones that have round balls.


sounds kinky until you look at it.

only downside i see to this kind of system is they are somewhat permanently installed. nice covering so they get less crap in them but short of like putting aquarium filters or something with a little more hutzpah (moving on from aerators here) and open the top and skimming and whatnot, I don't see how it stays clean over the long run although there are many accolades for these.

this is an alternative, forget if it was mentioned on this thread or one of the parallel threads going on a livestock forum on this topic or maybe just googling around. this waterer doesn't actually have a tank but drains out every time it is used and the animal triggers water with a physical push switch and excess water is drained into stone bed beneath the frost line.

nice idea if my excavator weren't laid up for a swing box seal and the ground wasn't about 9 degrees and the thing didn't cost $400 like about every solution I seem to be finding. also, a knock on these no standing water systems from some horse owners is that the horses learn not just to depress the water feeder to drink but play with them and run lots of water, more than the limited drainage capacity can handle making a mess.

meanwhile, back on the ranch, the horses are happily drinking from the trough modified as I mentioned, i.e. case ground for the heater run to it's own separate ground rod instead of to the power system grounding conductor that is bonded at the panel to the neutral. So haven't gotten anyone to rise to the bait as to whether I ought to put another GFCI in line as a super precaution. 

As I said, I've never, to my memory had a GFCI fail on. I've had plenty fail off. Don't what then the chances of having both the GFCI fail and the heater develop a fault in the same time frame between daily tests (simple enought to perform).

Not that I really care given their cost, but is there any fatigue that might be introduced by such frequent testing of the GFCI that anyone is aware of.

If anyone is aware of protection failures in GFCI, are the deus ex machina or might they be induced by line or current phenomenon so that putting two GFCIs in series wouldn't actually provide as much lower of a probability of failure as I imagine (i.e. inverse of the square of the probability of failure of a single GFCI).

and in the inventors side of the thing found various successful anti-icing uses of aquarium air pumps and found what looks to me to be a sightly more robust pump than for your average small aquarium that I might look to acquire in the construction of my own insulated stock tank with air agitation for ice prevention. so thanks for the help with that idea as well. I think the air in a plastic tube is will be much more highly resistive to transmitting NEV to the water in the trough even though the air pump itself is electric. 

This does get me back to asking what anyone thinks about my concern that pump based agitation where the water in the tank is circulating through an electric pump (or thermosiphoning through an electric heater) would transmit some of the NEV potential to the water tank? (and thanks JTM for that link to the propane block heater. don't know why that didn't come up when I was googling but that is friggin cool. as an aside, although the web site says they treat customers how they would want to be treated, i think most people would want to know what the thing costs and they don't list that and their 800 number is down. i'm afraid that the truth will be that it is another $400 solution albeit an elegrant one for its actual purpose where a truck or piece of equipment is parked remotely from electric supply. I can't tell from the e-literature how this is piloted, whether you have to light a standing pilot, or maybe it has a battery sparker or something. Anyway, I don't want to come off like a cheapskate. I'm not unwilling to spend $400 but I'm cautious about spending on the symptom and not the problem and then having diminished resources to deal with the problem, not to mention that I'm thinking the shear opportunity cost slowly tracking down NEV here and the half vocational half avocational time spent trying to get up to speed on it are a pretty serious investment on their own and if I were to reserve any of our limited funds for addressing that more globally rather than just at the water heater I need to husband those resources.

continued thanks for all the head scratching going on here.

brian


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## archibald tuttle (Dec 30, 2011)

PS - looking at something like this for an air pump and just have to think how to disperse air. I'm thinking letting the plastic run to some kind of adapter that would get me over to something heavier but somewhat corrosion resistant like a piece of copper or aluminum that would stay sunk in the tank and then drill some holes in that pipe for exhaust of air into the water.


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## hardworkingstiff (Jan 22, 2007)

archibald tuttle said:


> meanwhile, back on the ranch, the horses are happily drinking from the trough modified as I mentioned, i.e. case ground for the heater run to it's own separate ground rod instead of to the power system grounding conductor that is bonded at the panel to the neutral.


If I'm understanding you correctly, you grounded the heater case to earth via a ground rod and left the ground from the electrical circuit out (isolated)?


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## archibald tuttle (Dec 30, 2011)

hardworkingstiff said:


> If I'm understanding you correctly, you grounded the heater case to earth via a ground rod and left the ground from the electrical circuit out (isolated)?


that is correct.


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## JohnR (Apr 12, 2010)

My first instinct was to raise the size of the Neutral conductor. Now, while watching this Holt film, I see there is more to do a well.

Excellent thread.


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## JohnR (Apr 12, 2010)

Dennis Alwon said:


> I highly recommend you listen to this video
> http://www.mikeholt.com/strayVoltageVideo.php


If you look on that video at about the 7 hr mark:whistling2:, you will see he used 480Sparky's video of the hairdryer in the sink.

Oh, well, maybe it was just 75% mark or so.:laughing:


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## hardworkingstiff (Jan 22, 2007)

hardworkingstiff said:


> If I'm understanding you correctly, you grounded the heater case to earth via a ground rod and left the ground from the electrical circuit out (isolated)?





archibald tuttle said:


> that is correct.


I would be concerned, based on the last sentence of 250.4(A)(5)


> The earth shall not be considered as an effective ground-fault current path.


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## archibald tuttle (Dec 30, 2011)

hardworkingstiff said:


> I would be concerned, based on the last sentence of 250.4(A)(5)


HWS,

right, so I understand that is what it says. And yet we bond everything to earth and it is the (if you'll forgive the pun) the ground default current path as recognized in all these stray voltage discussions.

This was referenced earlier as an issue with the isolation transformer install where the secondary is not connected to the ground of the system and thus unbonded to the poco neutral. I think it was lou who said this might present the same code complication but someone else chimed in and said it might be appropriate with regard to objectionable voltage.

I don't encourage reckless disregard of important established practices, but neither do I shy from undertaking to rexamine established practice which tends to be a prisoner of the status quo and not deal well with the unintended consequences of rarer problems manifested by an otherwise standard practice.

So, I try to figure out what the code was trying to accomplish, and to what extent a similar margin of safety could be maintained through other means in outlier circumstances. After all, if one relied on the sense that the bonded grounds are considered an effective ground fault path and took that to the logical conclusion, then we wouldn't have GFCIs.

So of course I'm not running around clipping ground wires for the sheer fun of flouting my electrical elders, but all those who have never broken off the grounding prong on an extension cord because the next cord down the line is 2 wire please raise their hands . . . bueller, bueller . . . ?

So, when working outside I always try to be on a GFCI, esp. where conditions warrant. Many tools I use are 'double insulated' although ironically I can say that this setup has not insulated or protected myself or my workers from stray voltage for the same reason it doesn't protect the horses at the trough from stray voltage. We were grinding with diamond wheels on a foundation and floor with water keeping the dust down and started getting shocked without the GFCI tripping. so i test it an it seems OK, but I replaced it anyway and it was still happening. This was a couple months ago, now I know why.

So that being said, if there were an actual ground fault rather than NEV potential the matter would be much worse without the GFCI and they generally operate well to protect in these circumstances. So of course the trough heater is protected by a GFCI and the while the wire to earth from the heater case is not an effective ground fault path, I do believe it is an effective trigger for the ground fault protection device - which is a different issue.

So we are testing the GFCI daily while we assess other solutions -- and what I asked in a theoretical sense is would placing another GFCI in series with the current one not reduce the risk of failure of the GFCI essentially inverse to the square of the risk of failure of either GFCI alone -- in other words far more than say doubling the margin of safety in a straight line relationship.

Although I haven't run off to get an isolation transformer yet for several reasons. Because of phenomenon experienced when we were working (admittedly mixing eletricity and water for dust management) not only does the small isolation transformer seem an awfully expensive solution to protect essentially a single outlet but it wouldn't do anything for these other manifestations which are not as regular for us as the livestock watering problem but you might want a solution that went at the whole problem.

Unfortunately, secondary side and less expensive isolaters that have also been described on this thread do not appear to be available. I spoke directly with Ronk that makes a service level isolater for installation between the grounds of the primary and secondary at the poco transformer. That would be a good global solution but no small expense. Clever technology and if it were widely desired (which it might be if folks understood the problem) these might be as common as surge units for computers and coordinately less costly.

On the other hand, what is failure rate for these isolaters -- not high I'm sure but not zero. So now your ground fault path for which earth is not considered effective, or at least not solely effective, is now dependent on the functioning of the isolater. 

So I'm back to the same question using GFCI as the linchpin protection against ground fault. What are the chances of failure of the technology coupled with what are the chances of a ground fault circumstance or potential that will not trip overcurrent protection. And should I put two GFCIs in a row for the time being -- I'm not asking anyone to endorse that by the way but perhaps to look at the theory of to what extent that would further reduce risk, not whether it is adequate in the sense that I place reliance on any comments I might get on the subject.

Of some interest would be pointers to discussion of failure modes and circumstances for GFCIs or hazards not associated with failure but with current flows or timing that would not be expected by design to trip the GFCI.

Wouldn't be surprised if there are some good long threads on this and I will google GFCI failure and report anything interesting although if there are links here at ET by all means post them.
thanks,

brian


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## hardworkingstiff (Jan 22, 2007)

Brian,

Did you ever do some testing to determine if the potential is coming from the PoCo distribution system or from the premise (anyone on the common transformer) wiring?


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## archibald tuttle (Dec 30, 2011)

*need to prep everyone for power off . . .*

so have to pick a weekend when everyone can shut off all their computers and what not or at least be aware that we are going to shut them off. this weekend the weather is good and we're digging for our last project of the season so it may not be until next week.

thanks,

PS - can't keep it all in head, Lou and hardworkingstiff are the same guy.

thanks lou


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## Semi-Ret Electrician (Nov 10, 2011)

Brian, two GFCI's in series would be called redundant and if one failed the other would provide the 4 to 6 ma. protection to the user. Critical equipment designers sometimes employ tripple redundant computers. The two with the same answers are used... the one with a different answer is ignored.

But, GFCI's are very reliable and usually "fail safe" (off). And, as I mentioned in an earlier post, they aren't effective around livestock since livestock behavior is modified with as little as 1 ma. of shock.

Now, if you were to install GFCI breakers on all your suspect circuits (including the 240V loads) you may find what is causing your problem and if anything in the future creates a similar problem will also trip. This may allow you to take your eyes off the electrical equipment and back on farming, but again GFCI's trip between 4 to 6 ma., a GFP breaker trips at 30 ma. and a cow trips at 1 ma.

You could also measure for EGC current coming from your installed equipment using a clamp-on ammeter around the bare (or green) wire at each piece of equipment.

Or, permanently install a 25W 120V (or smaller) incandesent bulb in series with the ground wire, on every suspect piece of equipment, before it connects to the grounding system . If the lamp starts to glow that motor, heater etc. is developing a ground fault. Total cost to each piece of equipment...about $10 plus labor. Be advised..this would not satisfy Code.

All this (above) will only protect your farm if the NEV or ground fault is actually coming from your farm.


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## hardworkingstiff (Jan 22, 2007)

Semi-Ret Electrician said:


> All this (above) will only protect your farm if the NEV or ground fault is actually coming from your farm.


This determination is paramount. It dictates your course of action.


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## archibald tuttle (Dec 30, 2011)

Semi-Ret Electrician said:


> Brian, two GFCI's in series would be called redundant and if one failed the other would provide the 4 to 6 ma. protection to the user. Critical equipment designers sometimes employ tripple redundant computers. The two with the same answers are used... the one with a different answer is ignored.
> 
> But, GFCI's are very reliable and usually "fail safe" (off). And, as I mentioned in an earlier post, they aren't effective around livestock since livestock behavior is modified with as little as 1 ma. of shock.
> 
> ...


Gentlemen- and of course I use the term loosely most of the time so if the shoe fits wear it or if the cow s&%ts . . . well you get it.

anyway, definitely have bifurcated the approach. will attempt to identify the source - our side poco side - but also examining my temporary fix since it will remain in place pro-tem. 

I agree with you SRE that my observations have been largely that GFCIs fail off, I don't believe I've ever found one failed on. But one has to temper that with the question of how often are they really getting tested and do I have units out there in service that are failed on and I'm simply not aware of because they haven't been challenged. I especially wonder about this because it looks like the only systemtized random study of the question of which I'm aware found that many more GFCIs fail on than off.

That said, the total failure rate as reported from the field testing part of this trial seems to be about 10% and the vast majority of those are on although I got a .pdf and not an .xls of the raw data so I can't crunch the number myself quickly.

I'm kind of mystified that the report itself doesn't tease that figure out better, because obviously the concern with failure would be failure closed. and while there are a bunch of graphs and the 10% is my quick estimate by looking at them, as it turned out a good deal of the receptacles that failed the field test actually passed a bench test in the lab later and so it can be assumed that the field wiring was incorrect or the initial test results spurious.

Probably the most interesting section is the appendix cataloging the recovered devices with lab notes on probable causes of failure.

About equally prevalent in the No Trip , i.e. no protection, failures are power surge and contamination (there is also a result On, which means that it tripped but the power didn't go off, that is a much rarer result. I have to dig up the study authors at some point to understand that better but that is a very small fraction of instances.) So I think something like half the failures didn't test failed in the lab so you are down to a 5% failure rate and if you can knock out the half of those from contamination by careful installation, use and monitoring to avoid contamination (which including the obvious water penetration of the enclosure, insects and painting the receptacle) now you're down to a 2.5% failure rate mostly related to power surges. 

If I were able to add that margin again with a redundant GFCI protector in series on the same circuit that would reduce the risk to something on the order of 6/100ths %. And then you'd have to couple that with the actually likelihood of a fault occuring in order to get the actual risk of an accident r incident. But the problem (why is there always a friggin problem) is that redundancy doesn't necessarily give the same margin against dual failure if the likely failure is related to transient overvoltage because that could, in fact might likely, affect both GFCIs.

Maybe after reading this report what I really need (how many times can I hijack my own thread, trying to set a record here) is a good discussion of the most effective surge suppression. (we're kind of back to maybe an enormous uninterruptible power supply or maybe an isolation transformers because my experience is that transformers and batteries are the best soaks for overvoltage because none of the arrestors can really ground the transient voltage before it does damage, esp. to the kind of low load circuits that actually operate a GFCI.)

That said, I've experience a good deal of damage to sensitive electronics from lightening over the years and I still don't believe I've actually encountered one of the failed on GFCIs. 

In any event, there were very very few failures were the test appeared to trip the breaker but did not actually interrupt power, so more frequent testing is definitely called for and already been instituted. Further, we are able to monitor for the most obvious source of transient overvoltage, i.e. lightening, pretty easily to engage additional precautionary testing immediately in the wake of storms and most of such storms around these parts occur in the summer and not the winter so we wouldn't have this heater operation running during any likely lightening season. 

Your light bulb test is maybe another sensible indicator although given that earth is not as good a return as the bonded grounding conductor I'm wondering what kind of light bulb could give an indication of marginal failure of insulation in case the GFCI was bad on my system that has the casing earthed. I need a light bulb sensitive enough to pick up voltages in lower ranges but that wouldn't blow like a fuse if exposed to full phase voltage, i.e. 120 ish -- understanding that the phenomenon would be I think consequent of both current and voltage. Complicating this would be the impedance imposed by the direct earth ground. But maybe this could serve as an indicator of a failed ground fault if I can figure out the right bulb or flexible indicator load.


I think the bottom line is I'm going to dig out one of my plug in GFCI units for work and put that inline because it can't hurt and test 'em both regularly while trying to find the right troughs to foam together for a superinsulated trough with air agitation and while arranging to test whether the observed NEV is orginating on our side or the poco side of the service.

Oh finally SRE, i take your point about current lower than the trip current for the GFCI affecting livestock but, as with the discussion of NEV itself as opposed to exposure to fault current, I'm assuming that this is an effect short of death or acute injury. Obviously the other important factor related to animal husbandry is monitoring changes in behavior or condition that would suggest a problem so that chronic damage from exposure to such low amperage currents would definitely be on our radar along with the many other causes of poor keeping.

brian

thanks

brian


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## Dennis Alwon (May 9, 2009)

I find that many gfci units failed in the on position but I am not sure about the newer generation-- Definitely a problem with the older ones


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## archibald tuttle (Dec 30, 2011)

Dennis Alwon said:


> I find that many gfci units failed in the on position but I am not sure about the newer generation-- Definitely a problem with the older ones


Dennis,

as I said, I've never seen one failed on. Do you get a sense that some of these failed closed ones you have found have been subject to contamination (about half the problems found in the study). As to surges, unless folks are testing quite regularly they aren't likely to recall those phenomenon in association with the failed outlets.


Brian


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## Dennis Alwon (May 9, 2009)

Brian. I don't know. I have been back to many gfci's where the test button did not trip the device yet the unit was on. My suspicion is surges but I am not certain. They redesigned the GFCI's a while back and the new generations usually trip when they are first energized, they will not work when line and load is reversed-- neither of these features was true about the older generation. Now I am not certain if that has any impact on the failure- meaning will those newer features also make them fail in the off position.????


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## archibald tuttle (Dec 30, 2011)

*i gotta study the report some more*

they talked about different technologies and approximate ages of failed devices although interestingly the study seems to more or less have an even failure rate over time so failure is less linked to the age of the device and a device is just as likely to fail old as young.

as i said i don't have the raw data and can't apply statistical tools to back up my skimming so more on that later when i get a chance to get more indepth. but that would seem to coordinate with the research that says the vast majority of failures were form external causes, either surges or contamination and thus would only be modestly related to the age of the device.


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## Dennis Alwon (May 9, 2009)

Interestingly enough I have GFCI receptacle in my master bath that still works and has been there 27 years.


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