# Can a pool pump burn out GFCI receptacles?



## splatz (May 23, 2015)

I'd hunch that the GFCI is OK with the pool pump but the self-test mechanism might not be.


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## HackWork (Oct 2, 2009)

splatz said:


> I'd hunch that the GFCI is OK with the pool pump but the self-test mechanism might not be.


The one that I replaced was not self testing so I assume none of the other four before that were self testing either.


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## RePhase277 (Feb 5, 2008)

Put in a dead front GFCI feeding a regular receptacle and see it that fixes it. The heat from the plug blades may be enough to kill it.


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## splatz (May 23, 2015)

Hmm ... of course you hear of nuisance trips with pump motors etc. but I don't remember hearing of burning out GFCI receptacles ... could it be water or chlorine causing corrosion, maybe crack open the one you take out? Worth a look...


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## HackWork (Oct 2, 2009)

I actually put a brand-new box in when I installed the GFCI so I know it's sealed nicely. It's attached to the deck in a clean area away from the pool.

I just checked the supply house and they don't have any old stock of non-self testing GFCI's. But splatz, it was killing the GFCIs before self testing was around, so I am clueless.

I was thinking of putting a normal receptacle in and installing a GFCI breaker, kind a like re-phase'a idea.


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## MTW (Aug 28, 2013)

I had a fountain pump that seized up kill a WR GFCI once, not quite equivalent but I can see it happening.


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## splatz (May 23, 2015)

You could check the amps on the pump. And megger the motor. The megger everything, go megger the neighbors stuff and for that matter megger something in your van.


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## Navyguy (Mar 15, 2010)

I have found that any motor type load connected directly to a GFCI will kill it. I have seen it with Jacuzzi tubs, pool pumps, fountains, etc.

I have even seen where people use those "blow-up" Xmas decorations, the little blower motor kills the GFCI receptacle.

For interior applications I now use a deadfront and exterior I use a breaker unless it is a simple general use receptacle.

I have been told, although I cannot confirm with personal experience, that voltage drop is also a culprit. While I suspect that might be an issue with the electronics, I know that I only see it on specific applications such as motors / pumps and in many of them I would not consider the distance far enough to calculate voltage drop.

Cheers
John


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## HackWork (Oct 2, 2009)

I would assume that a deadfront GFCI has the same internal components as a normal GFCI receptacle, no?

Splatz, I like your idea, I wish I had an apprentice right now so I could megger him too.


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## joebanana (Dec 21, 2010)

Put a piece of black tape over the light.
It fixed my "check engine" light.
jk


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## frenchelectrican (Mar 15, 2007)

HackWork said:


> I would assume that a deadfront GFCI has the same internal components as a normal GFCI receptacle, no?
> 
> Splatz, I like your idea, I wish I had an apprentice right now so I could megger him too.


Hackwork .,, the deadfront GFCI do have same interal components as convential GFCI receptales do so.

I would check the current draw on the pump motor to make sure it is not over the motor specs. 

Ya spatz and rephase277 both have good idea about that.

I am thinking if sun is baking on that WP receptacle is ., if that the case it may cause to trip out sooner than it should be. 

Check the voltage when the pump is running to make sure you are not hitting low voltage issue there.


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## macmikeman (Jan 23, 2007)

Whoever came up with self testing gfi's (which cost more of course...) should be thrown into Hax's swimming pool with chains wrapped around him. 


They never even asked macmikeman if the whole self testing thing was a good idea before they jammed it thru the NEMA slaughter house. Stupid companies. 
Smart outfits will always come to macmikeman first for his opinion and then act.


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## emtnut (Mar 1, 2015)

I like @splatz meggering.

HP of pump ? Conductor size ? Current draw ?

I've run quite a few 1 hp AG pool motors with no problems.
My own pool is 1 hp jacuzzi, I installed the GFCI about 12yrs ago for it.
Short run, so no voltage drop to speak of.


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## Navyguy (Mar 15, 2010)

HackWork said:


> I would assume that a deadfront GFCI has the same internal components as a normal GFCI receptacle, no?


So I agree with that, but for some reason it seems to work better. We used to put GFCIs under the tub and kept getting call backs. Started putting deadfronts in, never a call back.

Again, not sure if it is voltage issue since the deadfront is right at the panel or if there are something different in them. Of course the other option is that some handyman ripped out the deadfront because it was easy to get to... something like AFCI breakers :jester:

Cheers
John


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## MechanicalDVR (Dec 29, 2007)

Navyguy said:


> I have found that any motor type load connected directly to a GFCI will kill it. I have seen it with Jacuzzi tubs, pool pumps, fountains, etc.
> 
> I have even seen where people use those "blow-up" Xmas decorations, the little blower motor kills the GFCI receptacle.
> 
> ...


:thumbsup:

I think you are spot on here. 

From what I have seen with outdoor wet bars and AG pools pumps motor loads kill GFCIs seasonally. 

The breaker is the best way to go in my past experience.


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## telsa (May 22, 2015)

Navyguy said:


> I have found that any motor type load connected directly to a GFCI will kill it. I have seen it with Jacuzzi tubs, pool pumps, fountains, etc.
> 
> I have even seen where people use those "blow-up" Xmas decorations, the little blower motor kills the GFCI receptacle.
> 
> ...


Thought experiment:

You have a 120 VAC L-N motor load. 

When the hot is broken, as it spools down, it's still generating Back EMF.

Where does that energy go ?

Down and out the neutral, that's where.

That's hard on the electronics of the GFCI receptacle. 

[ Electronics are polarity sensitive to a remarkable degree. ]

For that brief moment in time, the Back EMF functions as a Separately Derived (power) System... the neutral sees a return current pulse. 

That's why you're seeing such a high failure rate.

It'd be most interesting to see this pulse on a 'scope.


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## RePhase277 (Feb 5, 2008)

Motor loads like pumps seem to be pretty hard on friction connections like plugs and receptacles. My thoughts about the dead front GFI were more along the lines of separating the contact heating of the plug from the electronics of the GFI.


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## telsa (May 22, 2015)

RePhase277 said:


> Motor loads like pumps seem to be pretty hard on friction connections like plugs and receptacles. My thoughts about the dead front GFI were more along the lines of separating the contact heating of the plug from the electronics of the GFI.


Until a motor spools up... and generates back EMF... it functions like a bolted short... across the hot.

Then, when the power is cut, the back EMF pulses back out on the neutral.

Both flows are much more intense than the typical lighting load... because you have rotational inertia... and the motor may be all the way up to 12A full load current.

You just don't see that level of load in residential lighting circuits... often.


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## trentonmakes (Mar 21, 2017)

Is pump run 24/7 or do they yank the plug out at night?

I'd go with the gfci breaker and regular weatherproof outlet.

Possible to feed the pump on load side and put a switch on there to turn it on/off.

Not sure that will solve the problem though.






Seen As A Tiny Blip From Space


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## frenchelectrican (Mar 15, 2007)

trentonmakes said:


> Is pump run 24/7 or do they yank the plug out at night?
> 
> I'd go with the gfci breaker and regular weatherproof outlet.
> 
> ...


Well ya are pretty close on that idea .,, what about useing double pole switch that should take care of that issue due with double pole you are simuioustly turn the line and netural off or on same time that way you can reduce or elemated the EMF on that circuit.


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## MTW (Aug 28, 2013)

telsa said:


> Until a motor spools up... and generates back EMF... it functions like a bolted short... across the hot.
> 
> Then, when the power is cut, the back EMF pulses back out on the neutral.
> 
> ...



Except that the capacitor in a typical cap-start motor will absorb and cancel out any back EMF.


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## HackWork (Oct 2, 2009)

They leave the plug plugged in all the time with a good in-use cover. They switch the power to the GFCI on and off with a good 20A switch I installed.


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## emtnut (Mar 1, 2015)

HackWork said:


> They leave the plug plugged in all the time with a good in-use cover. They switch the power to the GFCI on and off with a good 20A switch I installed.


Maybe that's part of the problem ...

I've always switched pool motors on the 'load' side of the switch.
Maybe the GFCI doesn't like being powered up, and loaded at the same time


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## trentonmakes (Mar 21, 2017)

emtnut said:


> Maybe that's part of the problem ...
> 
> I've always switched pool motors on the 'load' side of the switch.
> Maybe the GFCI doesn't like being powered up, and loaded at the same time


I was hinting at that!
Lol






Seen As A Tiny Blip From Space


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## telsa (May 22, 2015)

MTW said:


> Except that the capacitor in a typical cap-start motor will absorb and cancel out any back EMF.


BTW, if there is no back EMF then the forward current = locked rotor amps.

It, the start circuit, can't cut back in until the motor has slowed down appreciably. 

It will also dump back EMF back onto the neutral, just out of phase with the run circuit. 

Further, its ability to absorb energy is nothing like the connection to the GEC System.

Both of these events will be brief, of course.

They are stressors that you don't have with lighting circuits.


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## MTW (Aug 28, 2013)

telsa said:


> BTW, if there is no back EMF then the forward current = locked rotor amps.
> 
> It, the start circuit, can't cut back in until the motor has slowed down appreciably.
> 
> ...


Oh no, not this again. :wallbash:


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## telsa (May 22, 2015)

One fine day you'll realize that the rotational energy of the motor has to go somewhere.

For L-N motors, it's going to overwhelmingly go into the Earth... or the process fluid.

You'll also come to understand that the spool-up amps are mighty impressive until the back EMF builds.

This is first week EE material.


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## dmxtothemax (Jun 15, 2010)

If these GFCI's are just failing electronically ?
then I would first of all check electrical specifications
spikes surges or even start up surges.
Other than that a corrosive atmosphere will play hell
with sensitive electronics in which case move the gfci 
well away from the pool environment.
perhaps even in the main panel.


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## MTW (Aug 28, 2013)

telsa said:


> One fine day you'll realize that the rotational energy of the motor has to go somewhere.
> 
> For L-N motors, it's going to overwhelmingly go into the Earth... or the process fluid.
> 
> ...


Reactive current returns to the source, not the earth. This is why poco's spend billions of dollars for power factor correction on the supply side. 

The is is first week EE material.


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## emtnut (Mar 1, 2015)

trentonmakes said:


> I was hinting at that!
> Lol
> 
> 
> ...


I looked back and saw your post :thumbsup:
I see Frenchelectrician 2nd'd it too ...

I guess I just turded it too :laughing:


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## telsa (May 22, 2015)

I suspect that GFCI receptacles that are dedicated to motor loads need to be more robust... very much in the same manner as motor rated switches.

If I had to point a finger, it would be the start up surge.

My second guess would be that the energy... however feeble... coming back the wrong way up the neutral... is messing with the solid state electronics... which are notoriously sensitive to polarity.


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## telsa (May 22, 2015)

MTW said:


> Reactive current returns to the source, not the earth. This is why poco's spend billions of dollars for power factor correction on the supply side.
> 
> The is is first week EE material.


The energy goes back to the GEC System, where the neutral is bonded to the Earth.

It then can go in EVERY direction. Its ultimate destination is heat. Heat in the process fluid ( water in this case ) in the mechanicals (bearings) and the impedance of the motor running as a power SOURCE... for the pitifully short period of time it's winding down to zero revs. The start circuit// windings change this principle not a whit. When they kick in, they join in.

You must understand, that for this brief moment in time, the Source of energy is NOT the Poco. It's the decay energy of the Back EMF. It's primal source is the rotational energy of the rotor. We're talking split seconds here. 

The original power flow// circuit is GONE. The hot has been broken.

So the power can't flow back to the source.

*The source is the motor, itself.*

If electronics were not sensitive to polarity, I wouldn't raise this as a factor. 

Solid state electronics are so sensitive to reverse polarity that diodes are festooned all over this or that design because of it. 

In the prior art: high vacuum technology ( vacuum tubes ) they weren't needed. Vacuum tubes are not remotely as sensitive to electrons going the wrong way.

In the early daze of solid state electronics -- this was a BIG design issue. It took YEARS for EEs to discover how many traditional circuits were generating reverse pulses of polarity that they never suspected. Eventually, they discovered that the only solution was to toss in diodes all over the joint. They were certainly cheap enough.

A GFCI is ultimately a balance detection circuit. The transient hammering between the hot inflow and the neutral outflow is something that I'd love to see on a very high speed scope. There figures to be SOME lag time as the current saturates the iron for the first time.

&&&

Ultimately, it would not surprise me that someone wakes up and comes out with a motor rated GFCI receptacle... just like we have motor rated switches.


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## trentonmakes (Mar 21, 2017)

telsa said:


> The energy goes back to the GEC System, where the neutral is bonded to the Earth.
> 
> It then can go in EVERY direction. Its ultimate destination is heat. Heat in the process fluid ( water in this case ) in the mechanicals (bearings) and the impedance of the motor running as a power SOURCE... for the pitifully short period of time it's winding down to zero revs. The start circuit// windings change this principle not a whit. When they kick in, they join in.
> 
> ...


Your saying this happens at startup and turning off the motor. Wouldn't a switch between said motor and gfci prevent this?
Not sure about the startup, but i could see what your saying on the motor winding down where I would think a switch would protect the outlet.






Seen As A Tiny Blip From Space


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## MTW (Aug 28, 2013)

telsa said:


> The energy goes back to the GEC System, where the neutral is bonded to the Earth.
> 
> It then can go in EVERY direction. Its ultimate destination is heat. Heat in the process fluid ( water in this case ) in the mechanicals (bearings) and the impedance of the motor running as a power SOURCE... for the pitifully short period of time it's winding down to zero revs. The start circuit// windings change this principle not a whit. When they kick in, they join in.
> 
> ...


Interesting, well I guess all the poco's must not know what you know since they waste so much time dealing with reactive current. You really should set them straight.


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## 3DDesign (Oct 25, 2014)

Install a 20amp spec grade weather resistant receptacle and a GFCI circuit breaker.


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## macmikeman (Jan 23, 2007)

I'd suggest a more efficient easier on the startup dc pool motor. lots of requests from customers for those units. Lowers the poco bill according to the hype.


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## telsa (May 22, 2015)

MTW said:


> Interesting, well I guess all the poco's must not know what you know since they waste so much time dealing with reactive current. You really should set them straight.


You dufus, the Poco is out of the equation as the motor spools down.

The hot has been broken.

They couldn't care a whit.


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## HackWork (Oct 2, 2009)

telsa, how do you determine if one is a dufus or a dunce?


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## telsa (May 22, 2015)

HackWork said:


> telsa, how do you determine if one is a dufus or a dunce?


It's a tough call.


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## lighterup (Jun 14, 2013)

This question is to Telsa..
Are you recommending a circuit breaker rather than a dead 
front gfci?
I say dead front , cause setting a standard gfci out at the pump 
is not feasible...the cord attachments on pool pumps are usually 
125 volt / 20 amp twist lock , so I usually set a dead front in a 4" 
square metal box w/ RS cover off an offset nipple right next to the
distribution panel and gfci the entire circuit (less digging - depth outside)


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## telsa (May 22, 2015)

lighterup said:


> This question is to Telsa..
> Are you recommending a circuit breaker rather than a dead
> front gfci?
> I say dead front , cause setting a standard gfci out at the pump
> ...


I'm merely speculating at this time.

Don't let me influence you.

My premise is that motor loads manage to hammer GFCI receptacles in a way non-motor loads don't... just like we see with switches.

A dead-front GFCI unit can't be worse than a standard GFCI receptacle... and may well be robust enough to make a difference, though exactly why is a puzzle.

Perhaps merely running cooler does the trick. 

( You know that the plug-receptacle connection is going to corrode over time... a pulse of heat during motor start-up might well be the difference maker. 

Alternately, it could be condensation that fries the electronics.

The consensus is that GFCI receptacles near pools & with motor loads are over prone to trigger complaints and call-backs. I hate those. )


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## lighterup (Jun 14, 2013)

telsa said:


> I'm merely speculating at this time.
> 
> Don't let me influence you.
> 
> ...


I read somewhere else once that , for recirculating pumps , that
dead fronts were prefered over the gfci receptacle. It is about 1/2 the
cost of a gfci circuit breaker. Also , even if allowed , it is recommended 
that electrician not go on the cheap and use 14 awg...keep everything 
20 amp , especially gfci device....due to possible / faster VD regardless
of distance w/ 14 awg...
I have not heard any complaints (yet-knock on wood) of pumps crapping
out or gfci dead front tripping (nuisance) so I will keep doing what i have
been..But once again , very thorough post ..educational ( for me as motors are a weak point in my scope of knowledge.:thumbsup:


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## MTW (Aug 28, 2013)

telsa said:


> You dufus, the Poco is out of the equation as the motor spools down.
> 
> The hot has been broken.
> 
> They couldn't care a whit.



Again, you're right. Poco's don't care about correcting power factor due to motor loads. They waste so much money every year doing that. They are so dumb.


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## telsa (May 22, 2015)

MTW said:


> Again, you're right. Poco's don't care about correcting power factor due to motor loads. They waste so much money every year doing that. They are so dumb.


You are lost ... and shovel in hand ... digging even deeper.

The discussion turns on the decay energy of a motor circuit that is wired L-N.

The Poco, and most of what you think you know about power circuits ... falls away.

The energy pulse is TRANSIENT, brief, and extremely variable.

The question remains: how does the balance circuit of a GFCI deal with dumped current on the neutral -- when there is NO current on the hot ?

My guess is: not too well.


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## telsa (May 22, 2015)

The logic of a GFCI balance circuit is that the neutral return current will be LOWER than the hot going out.

I.e. the hot current is going astray.

When a rotor is spooling down, it's back EMF can't travel back up the hot. 

The switch has broken that connection.

It's still able to dump energy out the grounded neutral, though.

For those expecting to see a completed circuit -- this pulse is radiated energy -- very much like an antenna.

And the balance circuit is sitting right on this antenna.

If it is not robust enough, it fails in service.

&&&

Non-motor rated switches can often still do the job... they just don't last hardly any time at all.

Motor loads are simply more demanding... so much so that they have their own NEC sub-head.


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## telsa (May 22, 2015)

If the motor switch was a double-pole switch that broke the hot and neutral at the same time...

Well, that's worth inspection.


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## lighterup (Jun 14, 2013)

telsa said:


> If the motor switch was a double-pole switch that broke the hot and neutral at the same time...
> 
> Well, that's worth inspection.


Question...if you use a double pole switch on a L-N wired motor
and disconnect simultaneously , what then will happen to the
back electro magnetic force that was being dumped back thru
the neutral? Will this create a non existent pathway for back 
EMF and then subsequently "screw up" the motor?


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## nrp3 (Jan 24, 2009)

I would think it wasn't any different than a 240v motor on a two pole. No problems there.


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## telsa (May 22, 2015)

lighterup said:


> Question...if you use a double pole switch on a L-N wired motor
> and disconnect simultaneously , what then will happen to the
> back electro magnetic force that was being dumped back thru
> the neutral? Will this create a non existent pathway for back
> EMF and then subsequently "screw up" the motor?


It would dissipate as pure heat... into the motor windings... etc.


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## MTW (Aug 28, 2013)

lighterup said:


> Question...if you use a double pole switch on a L-N wired motor
> and disconnect simultaneously , what then will happen to the
> back electro magnetic force that was being dumped back thru
> the neutral? Will this create a non existent pathway for back
> EMF and then subsequently "screw up" the motor?


Don't listen to a word Telsa says on this subject, he is completely wrong. All reactive current (back EMF) is in opposition to the source current, therefore it is traveling to the source. Some reactive current will dissipate as heat due to I2R losses, but the current itself is traveling to the source.


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## MTW (Aug 28, 2013)

telsa said:


> You are lost ... and shovel in hand ... digging even deeper.
> 
> The discussion turns on the decay energy of a motor circuit that is wired L-N.
> 
> ...


There is no such thing as "decay energy" in a motor circuit. Motors don't magically turn into generators when they are turned off and wind down. 

Once the switch is opened, there's an open circuit. Current isn't "dumped" onto the neutral once an open circuit is created. 

By by all means, keep spouting this nonsense. It's very entertaining.


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## macmikeman (Jan 23, 2007)

Since we are talking back emf, and collapsing currents, then why does listening to Pink Floyd's echoes always put me to sleep?


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## nrp3 (Jan 24, 2009)

Or most anything from Dark Side Of The Moon.


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## HackWork (Oct 2, 2009)

I just changed out the GFCI. It was completely dry and looked in perfect condition. The self test said that it was dead.

I put a new GFCI in, when I turned the pump on and then off it made some odd sounds as it was turning down. I'm not sure if that was bearings or not. I told the customer that if this happens again will have to rework the system to get rid of the GFCI receptacle. I also told him that he should consider a new pump.


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## nrp3 (Jan 24, 2009)

I rewired a couple of them yesterday and they make a clicking noise either when shut off or turned on. I think there is some sort of switch in the end housing.


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## telsa (May 22, 2015)

MTW said:


> Don't listen to a word Telsa says on this subject, he is completely wrong. All reactive current (back EMF) is in opposition to the source current, therefore it is traveling to the source. Some reactive current will dissipate as heat due to I2R losses, but the current itself is traveling to the source.


Buddy, you've just flunked physics. 

For the rest of the commentariat: study Cooper Bussman's short circuit calculations when a motor load is involved.

[ Ugly's page 59 ... Fault #2. ]

Every broken hot ( switch unmade ) follows the physics of fault #2... with the exception that there is no up-the-line fault current contribution.

Realize that the motor contribution collapses as the rotor spools down.


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## MTW (Aug 28, 2013)

telsa said:


> Buddy, you've just flunked physics.
> 
> For the rest of the commentariat: study Cooper Bussman's short circuit calculations when a motor load is involved.
> 
> ...


Oh, sorry, I forgot it's your job to troll the forum. Carry on.


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## RePhase277 (Feb 5, 2008)

Motors do act like generators when the circuit is open. It's called motor contribution and can be pretty large when calculating fault currents.

The EMF of an open motor empties itself across the arc of the opening switch. That's why there is an arc. Nature doesn't want that current to stop, so it tries to supply whatever voltage is necessary to sustain the current,hence the arc. At some point, the energy has wasted itself as friction in the spinning down motor and the arc.


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## macmikeman (Jan 23, 2007)

RePhase277 said:


> Motors do act like generators when the circuit is open. It's called motor contribution and can be pretty large when calculating fault currents.
> 
> The EMF of an open motor empties itself across the arc of the opening switch. That's why there is an arc. Nature doesn't want that current to stop, so it tries to supply whatever voltage is necessary to sustain the current,hence the arc. At some point, the energy has wasted itself as friction in the spinning down motor and the arc.



Damnit, we just got MTW back and now he is gonna slink away again before we get a chance to look at pictures of his mom's basement.


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## frenchelectrican (Mar 15, 2007)

HackWork said:


> I just changed out the GFCI. It was completely dry and looked in perfect condition. The self test said that it was dead.
> 
> I put a new GFCI in, when I turned the pump on and then off it made some odd sounds as it was turning down. I'm not sure if that was bearings or not. I told the customer that if this happens again will have to rework the system to get rid of the GFCI receptacle. I also told him that he should consider a new pump.


That would be a good idea but if that pump is pretty old then it is the time to get new one. ( there is a trust bearing in there and when it get worn out it will make funny noise when they coast down but it can masked with starting switch on single phase motors )



nrp3 said:


> I rewired a couple of them yesterday and they make a clicking noise either when shut off or turned on. I think there is some sort of switch in the end housing.


Typical most single phase motors do have starting switch but couple single phase motors dont have starting switch espcally with PSC or shaded pole that is pretty much self starting.


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## RePhase277 (Feb 5, 2008)

macmikeman said:


> Damnit, we just got MTW back and now he is gonna slink away again before we get a chance to look at pictures of his mom's basement.


First of all, my man Peter D don't slink for anyone. Secondly, it's his aunt's basement.


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## telsa (May 22, 2015)

MTW said:


> There is no such thing as "decay energy" in a motor circuit. *Motors don't magically turn into generators when they are turned off and wind down. *
> 
> [ Flunk class a second time. ]
> 
> ...




*Where do you come up with this utter nonsense.*

An over-driven DC motor turns into a generator instead of a motor.

Even Edison found that much out... and very quickly, too.

He pressed Tesla to solve the problem of teamed-up DC generator oscillations... which directly led to the Infinite Bus and the Synchronous motor. Even Tesla couldn't get twinned DC generators to operate in harmony. ( long before electronics )

Even asynchronous motors can be induced to generate power... and are the basis of rotary phase converters. 

&&&&

Lastly, motor-rated switches are robust because of the need to survive breaking the current. That's what pits the contacts. Pulling them apart is what establishes an arc.

But since AC commutes at 120 times per second, AC switches don't need to be as robust as DC switches. 

This latter fact is what really destroyed Edison's DC. There are gazillion switches upon the grid. If they were all switching DC, they'd have to be 6 times as robust... and expensive. The next time you take a look at motor-rated switches that have DC ratings, too... check out the amperage gap.

MTW, I know that this is all too much for you. I post for the readership. I don't want them to wallow in ignorance.


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## MTW (Aug 28, 2013)

RePhase277 said:


> Motors do act like generators when the circuit is open. It's called motor contribution and can be pretty large when calculating fault currents.
> 
> The EMF of an open motor empties itself across the arc of the opening switch. That's why there is an arc. Nature doesn't want that current to stop, so it tries to supply whatever voltage is necessary to sustain the current,hence the arc. At some point, the energy has wasted itself as friction in the spinning down motor and the arc.


Telsa said that energy is dissipated into the neutral and then goes into the earth.

Who should I believe? :whistling2:


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## MTW (Aug 28, 2013)

telsa said:


> *Where do you come up with this utter nonsense.*
> 
> An over-driven DC motor turns into a generator instead of a motor.
> 
> ...


They'll still be in ignorance if they believe anything you say.


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## telsa (May 22, 2015)

RePhase277 said:


> Motors do act like generators when the circuit is open. It's called motor contribution and can be pretty large when calculating fault currents.
> 
> The EMF of an open motor empties itself across the arc of the opening switch. That's why there is an arc. Nature doesn't want that current to stop, so it tries to supply whatever voltage is necessary to sustain the current,hence the arc. At some point, the energy has wasted itself as friction in the spinning down motor and the arc.


He's stuck on stupid.

It's only important that others realize that he's talking through his hat. :thumbsup:


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## MTW (Aug 28, 2013)

telsa said:


> He's stuck on stupid.
> 
> It's only important that others realize that he's talking through his hat. :thumbsup:


Speaking of stupid:


http://www.electriciantalk.com/f30/what-can-cause-all-lights-circuit-fry-119010/index2/#post2170137


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## RePhase277 (Feb 5, 2008)

MTW said:


> Telsa said that energy is dissipated into the neutral and then goes into the earth.
> 
> Who should I believe? :whistling2:


Joseph Henry and Michael Faraday are the ones I would believe. 

If Bob Badger, Mike Holt, and Speedy Deletey somehow cloned Leonardo da Vinci, the four of them together wouldn't know more about it than those two.


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## HackWork (Oct 2, 2009)

I don't know what any of you are talking about and wish you would dumb it down for me.


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## macmikeman (Jan 23, 2007)

Instead of this debate, today I went and ran 1,200 feet of 12-2 thru a house open attic and studs, and another 250 feet of 14-2 as well. Not bad for an old codger. So tomorrow or the next day or so when I go back I still got to do all the lights, dryer, h20 htr, and sub panel feeder, then make up the sub panel for rough in, and splice and cut in all the boxes. This'll probably take another 3 or 4 days to get to rough in inspection time, but today was only day #1. P.S. for the purists, I didn't work all last week, it was take a break week, so who cares if it is Sunday or not.


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## RePhase277 (Feb 5, 2008)

I picked up 900 watts of solar panels and only $320. I wonder if this is what gangstas feel like?


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## HackWork (Oct 2, 2009)

macmikeman said:


> P.S. for the purists, I didn't work all last week, it was take a break week, so who cares if it is Sunday or not.


Screw the purists. If there is money to be made, what's the difference in the day of the week?

I'd rather work Saturday and Sunday and have a couple weekdays off when no one else is around.


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## HackWork (Oct 2, 2009)

RePhase277 said:


> I picked up 900 watts of solar panels and only $320. I wonder if this is what gangstas feel like?


You didn't choose the thug life. The thug life chose you.


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## MechanicalDVR (Dec 29, 2007)

macmikeman said:


> Since we are talking back emf, and collapsing currents, then why does listening to Pink Floyd's echoes always put me to sleep?


When you listen to Floyd are you under the influence of anything at the time?:cool2:


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## macmikeman (Jan 23, 2007)

MechanicalDVR said:


> When you listen to Floyd are you under the influence of anything at the time?:cool2:


You should have asked me that question the first time I saw the Pink Floyd......................... hoo boy ...............


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## RePhase277 (Feb 5, 2008)

HackWork said:


> You didn't choose the thug life. The thug life chose you.


"They see me solar, they hatin'..."


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## HackWork (Oct 2, 2009)

rephase277 said:


> i picked up 900 watts of solar panels and only $320. I wonder if this is what gangstas feel like?


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## MechanicalDVR (Dec 29, 2007)

nrp3 said:


> I rewired a couple of them yesterday and they make a clicking noise either when shut off or turned on. I think there is some sort of switch in the end housing.


Sure is, it's the centrifugal switch in the end bell.


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## RePhase277 (Feb 5, 2008)

MechanicalDVR said:


> When you listen to Floyd are you under the influence of anything at the time?:cool2:


Pink Floyd just sounded like gibberish until I finally listened under the influence. Changed my life


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## HackWork (Oct 2, 2009)

MechanicalDVR said:


> Sure is, it's the centrifugal switch in the end bell.


Why does it make screwy noises after the power is cut and the motor spins down?


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## MechanicalDVR (Dec 29, 2007)

RePhase277 said:


> I picked up 900 watts of solar panels and only $320. I wonder if this is what gangstas feel like?


Not even close. 

'Gangsters' pick up 900 solar panels and sell them for $50-$100 a piece and pocket 100% profit.:whistling2:


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## RePhase277 (Feb 5, 2008)

HackWork said:


> Why does it make screwy noises after the power is cut and the motor spins down?


Because the RPMs go below the threshold where the switch opens the start circuit. It's usually a couple of weights on pivots with a couple of springs attached. Squirt it with some silicone spray and it will probably quiet down.


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## MechanicalDVR (Dec 29, 2007)

HackWork said:


> Why does it make screwy noises after the power is cut and the motor spins down?


Drag of a worn switch can almost sound like worn gears at times.


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## MechanicalDVR (Dec 29, 2007)

RePhase277 said:


> Because the RPMs go below the threshold where the switch opens the start circuit. It's usually a couple of weights on pivots with a couple of springs attached. S1uirt it with some silicone spray and it will probably quiet down.


Some times, others not really.


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## RePhase277 (Feb 5, 2008)

MechanicalDVR said:


> Some times, others not really.


That literally applies to every single problem and potential solution ever:laughing:


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## MechanicalDVR (Dec 29, 2007)

RePhase277 said:


> That literally applies to every single problem and potential solution ever:laughing:


LOL but it's true. As long as the switch still works I've never pulled them apart but I've seen worn springs hang up and let go with a loud snap once lubed and they will function the next few start-stops and go back to the same problem again.


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## oliquir (Jan 13, 2011)

you must put the switch after the gfci, if it is before any electrical noise will go back to the gfci, if not possible then use a gfci breaker or dead front gfci


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## HackWork (Oct 2, 2009)

oliquir said:


> you must put the switch after the gfci, if it is before any electrical noise will go back to the gfci, if not possible then use a gfci breaker or dead front gfci


So it's my fault now, huh? 

What about gfci receptacles in garages where saws and vacuums and other motors are plugged in?


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## RePhase277 (Feb 5, 2008)

HackWork said:


> So it's my fault now, huh?
> 
> What about gfci receptacles in garages where saws and vacuums and other motors are plugged in?


Probably the difference between universal motors and induction motors...


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## HackWork (Oct 2, 2009)

RePhase277 said:


> Probably the difference between universal motors and induction motors...


What about a fan or refrigerator?


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## RePhase277 (Feb 5, 2008)

HackWork said:


> What about a fan or refrigerator?


I dunno... two things come to mind for me: there was a time when refrigerators and other equipment wasn't required to be GFCI protected due to being large and dedicated. I still don't see many refrigerators on GFCIs, and those that are, they usually are plugged into a protected outlet, not the GFCI directly. The second thing is motor size. Fractional horsepower.

I am just spit balling here.


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## emtnut (Mar 1, 2015)

Maybe I'll rewire my fridge, so that the relay shuts the line side of the gfci instead of the motor :laughing:

You had the answer at post #24 :whistling2: ... just sayin ..


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## HackWork (Oct 2, 2009)

RePhase277 said:


> I dunno... two things come to mind for me: there was a time when refrigerators and other equipment wasn't required to be GFCI protected due to being large and dedicated. I still don't see many refrigerators on GFCIs, and those that are, they usually are plugged into a protected outlet, not the GFCI directly. The second thing is motor size. Fractional horsepower.
> 
> I am just spit balling here.


Alright, I guess I'll just have to accept responsibility and kill myself. I could see that's everyone's end goal here. The only question now is how.


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## RePhase277 (Feb 5, 2008)

HackWork said:


> Alright, I guess I'll just have to accept responsibility and kill myself. I could see that's everyone's end goal here. The only question now is how.


That's the spirit, you got real moxy kid! I suggest you travel up to Chester, VT and blow your brains out all over a chicken coup. Use a shotgun and make it real messy. It's only a 4 hour drive. You can do it on a single tank I bet.

Edit: Fix the pool pump circuit first.


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## emtnut (Mar 1, 2015)

Put your tools out in the laneway


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## HackWork (Oct 2, 2009)

RePhase277 said:


> That's the spirit, you got real moxy kid! I suggest you travel up to Chester, VT and blow your brains out all over a chicken coup. Use a shotgun and make it real messy. It's only a 4 hour drive. You can do it on a single tank I bet.
> 
> Edit: Fix the pool pump circuit first.


This is unacceptable.


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## oliquir (Jan 13, 2011)

HackWork said:


> So it's my fault now, huh?
> 
> What about gfci receptacles in garages where saws and vacuums and other motors are plugged in?


Problem is not the switch before the gfci, it is switching the gfci while there is a motor load on it.


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## HackWork (Oct 2, 2009)

oliquir said:


> Problem is not the switch before the gfci, it is switching the gfci while there is a motor load on it.


When I changed the GFCI yesterday I found out that there is a timer in the basement that turns the pump on and off. The homeowner only uses the switch to turn the pump off if it's on while he is out there doing some type of maintenance, which isn't that often.

The end result is still the same, I just figured I would lay out all the facts of the situation.


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## RePhase277 (Feb 5, 2008)

HackWork said:


> This is unacceptable.


Ok, I'll go half-sies on the gas.


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## emtnut (Mar 1, 2015)

I'm rather upset that this post hasn't gone any further ....

Nothing further, just expected some would jump on it :whistling2:


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## nrp3 (Jan 24, 2009)

I have a customer who I changed the pool timer two yrs in a row before I went back to a mechanical timer. Why, I have no idea.


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## trentonmakes (Mar 21, 2017)

emtnut said:


> Maybe I'll rewire my fridge, so that the relay shuts the line side of the gfci instead of the motor :laughing:
> 
> You had the answer at post #20 :whistling2: ... just sayin ..


Fixed it  






Seen As A Tiny Blip From Space


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## emtnut (Mar 1, 2015)

trentonmakes said:


> Fixed it
> 
> 
> 
> ...


Well, as you said .. You 'hinted' at it :thumbsup:

Correction noted


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## trentonmakes (Mar 21, 2017)

If its on a timer and its working, why is he dicking around with it?

Just give him a dedicated outlet for his weed whacker!






Seen As A Tiny Blip From Space


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## HackWork (Oct 2, 2009)

trentonmakes said:


> If its on a timer and its working, why is he dicking around with it?
> 
> Just give him a dedicated outlet for his weed whacker!


It's all in the first post buddy.


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## emtnut (Mar 1, 2015)

HackWork said:


> When I changed the GFCI yesterday I found out that there is a timer in the basement that turns the pump on and off. The homeowner only uses the switch to turn the pump off if it's on while he is out there doing some type of maintenance, which isn't that often.
> 
> The end result is still the same, I just figured I would lay out all the facts of the situation.


I'd say in this situation, if you do have to go back for another bad GFCI ...

Either change the wiring for the timer to be on the load side of the outdoor gfci, or just change to a gfci breaker. That way the timer in the basement will be on the load side.
I think that will be a good permanent fix !


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## trentonmakes (Mar 21, 2017)

HackWork said:


> When I changed the GFCI yesterday I found out that there is a timer in the basement that turns the pump on and off. The homeowner only uses the switch to turn the pump off if it's on while he is out there doing some type of maintenance, which isn't that often.
> 
> The end result is still the same, I just figured I would lay out all the facts of the situation.


Above ground?
Im assuming maintenance is vacuming, backwash, waste, rinse.....
Thats alot of on off cycles even if it is once in awhile.

I think what EMT said is best bet.

All our pools we use a gfci breaker feeding a relay or timer and pump is on load side of relay/timer.

Never any issues






Seen As A Tiny Blip From Space


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## HackWork (Oct 2, 2009)

trentonmakes said:


> Above ground?
> Im assuming maintenance is vacuming, backwash, waste, rinse.....
> Thats alot of on off cycles even if it is once in awhile.


Why are you arguing with the customer? He said he doesn't shut it off often. Should I go beat a confession out of him for you? Cause I will if it gets you off my back.


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## trentonmakes (Mar 21, 2017)

HackWork said:


> Why are you arguing with the customer? He said he doesn't shut it off often. Should I go beat a confession out of him for you? Cause I will if it gets you off my back.


ALWAYS take what the customer says with a grain of salt.






Seen As A Tiny Blip From Space


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## emtnut (Mar 1, 2015)

HackWork said:


> Why are you arguing with the customer? He said he doesn't shut it off often. Should I go beat a confession out of him for you? Cause I will if it gets you off my back.


It's exactly THIS .... as to why you and I don't get along.

We were both trying to help you ... If your azz is burning, go the fcuk to bed.


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## HackWork (Oct 2, 2009)

trentonmakes said:


> ALWAYS take what the customer says with a grain of salt.


When I am making $150 for 7 minutes to change out a GFCI on the way to get a cup of coffee, I will listen to anything they have to say.


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## trentonmakes (Mar 21, 2017)

emtnut said:


> It's exactly THIS .... as to why you and I don't get along.
> 
> We were both trying to help you ... If your azz is burning, go the fcuk to bed.


Insanity is doing the same thing over and over and expecting different results!
Lol






Seen As A Tiny Blip From Space


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## emtnut (Mar 1, 2015)

trentonmakes said:


> Insanity is doing the same thing over and over and expecting different results!
> Lol
> 
> Seen As A Tiny Blip From Space


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## MechanicalDVR (Dec 29, 2007)

emtnut said:


>


Or 'Rationality' challenged.


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## macmikeman (Jan 23, 2007)

I would have sold the guy a dc drive soft starting motor. Only $1400 installed.


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## HackWork (Oct 2, 2009)

macmikeman said:


> I would have sold the guy a dc drive soft starting motor. Only $1400 installed.


Next time :thumbsup:


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## macmikeman (Jan 23, 2007)

Actually, the reality is , in 9 out of 10 cases , the pool guy beats me to that sale, cause he has better access to the owner since he comes around once a week and those pool guys are not as stupid as they look. 

Maybe being a pool guy/ service electrician is the answer to all the problems of how to get jobs coming in steady when doing electrical service work, and ,,,, Mrs. Robinson would probably think this is a peachy idea.


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