# Stumped



## WronGun (Oct 18, 2013)

I took a troubleshoot service Call today...

Gfci Receptacle keeps tripping.

The gfci powers up fine with the line hooked up and trips only with the load going out to the shed.

The line to the shed was completely isolated and disconnected at the other end, tested for continuity between all 3 conductors , all good ...

I even bypassed the gfci and ran straight power to the shed 120v to N and G, all good.

But no matter what it trips when it connected to the load side of gfci

Tried 3 GFCI's to make sure I didn't have a bad one.

I'm stumped ! 


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## HackWork (Oct 2, 2009)

Continuity testing isnt good enough. This when you need a megger. You have a very slight ground fault in the line that isn't making good enough contact to set off your continuity tester.


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## WronGun (Oct 18, 2013)

HackWork said:


> Continuity testing isnt good enough. This when you need a megger.




I've only used a megger for testing MI lines , not familiar , never used one in Resi...

I will look up some stuff online , any recommendations on which I should buy?


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## splatz (May 23, 2015)

The megger is almost certainly going to tell the tale. 

If you clamp around the hot and neutral and you don't see zero amps, the GFCI is tripping for the right reason.


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## HackWork (Oct 2, 2009)

I bought the Fluke because it's a one time purchase for life. I believe the model is the 1507. It's the megger without the other multimeter functions. It was around $425 at the time but I bought it used for around half that.

I don't use it often, but this is exactly when I would pull it out.


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## trentonmakes (Mar 21, 2017)

Slight nick in wire

Is it in pvc....likely there water in it

ANSWERE THE QUESTION STEVIE!


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## socket2ya (Oct 27, 2016)

Maybe you can cheat and put the feed and load wires to line at the house GFI, then put another GFI out at the shed


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## MechanicalDVR (Dec 29, 2007)

WronGun said:


> I took a troubleshoot service Call today...
> 
> Gfci Receptacle keeps tripping.
> 
> ...


*I second Hack, get a megger!*


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## HackWork (Oct 2, 2009)

A trick I used before is to find the bad conductor, then reidentfy it to ground. Then reidentify the 2 good conductors as the hot and neutral.


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## trentonmakes (Mar 21, 2017)

So the megger will tell you which conductor is bad?

That beats repulling!

ANSWERE THE QUESTION STEVIE!


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## splatz (May 23, 2015)

There's a Fluke 1503 now that's a little cheaper than the 1507 or 1587 - it's going for $449.00 at authorized fluke distributors, probably a little cheaper on ebay. 

Amprobe makes an analog one that's not that bad for $120 or so, the Amprobe AMB-3 if you're not ready to shell out for the Fluke.


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## WronGun (Oct 18, 2013)

Its UF cable 


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## MechanicalDVR (Dec 29, 2007)

socket2ya said:


> Maybe you can cheat and put the feed and load wires to line at the house GFI, then put another GFI out at the shed




Then when it's raining and somebody gets fried the shed will still have power?


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## HackWork (Oct 2, 2009)

WronGun is a contractor and seems to be doing well so I say just go for the Fluke. 

What's the difference between the 1503 and 1507?


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## splatz (May 23, 2015)

trentonmakes said:


> So the megger will tell you which conductor is bad?
> 
> That beats repulling!


The continuity tester tests for resistance to ground at a very low voltage, the megger tests that too but at a high voltage. Faults that won't show up with a continuity test will show up with a megger. The conductor with a path to ground on the megger test is the bad one. (If the cable's crushed or etc. it could be both / all.)


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## MechanicalDVR (Dec 29, 2007)

splatz said:


> There's a Fluke 1503 now that's a little cheaper than the 1507 or 1587 - it's going for $449.00 at authorized fluke distributors, probably a little cheaper on ebay.
> 
> Amprobe makes an analog one that's not that bad for $120 or so, the Amprobe AMB-3 if you're not ready to shell out for the Fluke.



The amprobe is fine for this type thing.

I only break out the 1587 for motors, compressors and that type thing.


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## drewsserviceco (Aug 1, 2014)

hackwork said:


> wrongun is a contractor and seems to be doing well so i say just go for the fluke.
> 
> What's the difference between the 1503 and 1507?



0004


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## HackWork (Oct 2, 2009)

Ive been buying from Tequipment.net for years.

http://www.tequipment.net/Fluke1503.html
http://www.tequipment.net/Fluke1507.html?v=0


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## WronGun (Oct 18, 2013)

Definitely going for the fluke, and this UF runs alongside an underground pool, definitely not doing anything shady.


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## trentonmakes (Mar 21, 2017)

I like Hacks idea of reidentifying the wires once you locate the/A bad conductor



ANSWERE THE QUESTION STEVIE!


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## splatz (May 23, 2015)

HackWork said:


> WronGun is a contractor and seems to be doing well so I say just go for the Fluke.
> 
> What's the difference between the 1503 and 1507?


That's true, it's nothing to @WronGun he spent more than this on custom shelf liners for his van. 

I'd definitely get the 1507 over the 1503 looking at this, I'd want the ability to test at 50-100-250v, maybe hold out for the 1587 if you want full multimeter functions as well.


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## WronGun (Oct 18, 2013)

HackWork said:


> A trick I used before is to find the bad conductor, then reidentfy it to ground. Then reidentify the 2 good conductors as the hot and neutral.




If there was an issue wouldn't that mean that 2 wires were compromised , or 1 wire was compromised and touching the G.

Also , would it even be safe to use the bare ground as a H?


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## WronGun (Oct 18, 2013)

1507 for $590, you know I'm still dreading the fact I had to spend $530 on a 14' step ladder this week !

I really don't care for a multimeter on it

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## splatz (May 23, 2015)

WronGun said:


> Also , would it even be safe to use the bare ground as a H?


Yes, if it's 12v like on overhead cable lights.


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## splatz (May 23, 2015)

WronGun said:


> If there was an issue wouldn't that mean that 2 wires were compromised , or 1 wire was compromised and touching the G.


If one wire is nicked and touching ground, or just in contact with ground through water, you'll have a high resistance short. 

Hack's trick would only work for an insulated ground big enough to reidentify.


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## splatz (May 23, 2015)

WronGun said:


> Definitely going for the fluke, and this UF runs alongside an underground pool, definitely not doing anything shady.


By all means spend it if you got it but there's nothing shady about the amprobe, you're using it as a diagnostic tool. 

Actually I am pretty sure you're going to be digging up a UF cable, the amp clamp trick would be enough to convince me there's a fault, then you can use other means to determine whether you can find the fault without digging up the whole thing. 

Remember what I was saying a couple weeks ago about friends don't let friends bury cables?


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## socket2ya (Oct 27, 2016)

MechanicalDVR said:


> Then when it's raining and somebody gets fried the shed will still have power?


I'm looking at table 300.5 column 3 and my understanding is that 120v underground wiring with or without protection buried 18" or deeper is not required to be GFCI protected.


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## WronGun (Oct 18, 2013)

splatz said:


> By all means spend it if you got it but there's nothing shady about the amprobe, you're using it as a diagnostic tool.
> 
> 
> 
> ...




Ya, I remember.... I already told him let's get rid of this and run pipe and install a sub.... it's going to a shed that he's expanding ... not much to think about here. 

I ordered the 1507 on Amazon for 547- I'm too early in my career to even contemplate buying it 


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## socket2ya (Oct 27, 2016)

If the wire is knicked then it probably isnt 18" deep I would guess


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## trentonmakes (Mar 21, 2017)

socket2ya said:


> If the wire is knicked then it probably isnt 18" deep I would guess


I had a neutral wire,thnn, nicked in pvc at 18in

It was installed last year and kept tripping, pvc had water in it and was the 3rd light out of 4. 

Ended up pulling it and repulling new wire, the megger and Hacks tip would of saved a bit of work in that case.

ANSWERE THE QUESTION STEVIE!


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## MechanicalDVR (Dec 29, 2007)

socket2ya said:


> I'm looking at table 300.5 column 3 and my understanding is that 120v underground wiring with or without protection buried 18" or deeper is not required to be GFCI protected.


I couldn't care any less in this case, if you know a UF run underground is bad and just try to avoid it you could injure someone when it deteriorates a tad further.

Just not a wise choice to avoid the proper repair.

Now that he says it runs along an inground pool it just makes avoidance that much worse.


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## MechanicalDVR (Dec 29, 2007)

socket2ya said:


> If the wire is knicked then it probably isnt 18" deep I would guess


The nicked conductor could be in a conduit 7' deep and as long as the water level in the conduit didn't reach it there would be no problem.


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## socket2ya (Oct 27, 2016)

MechanicalDVR said:


> I couldn't care any less in this case, if you know a UF run underground is bad and just try to avoid it you could injure someone when it deteriorates a tad further.
> 
> Just not a wise choice to avoid the proper repair.
> 
> Now that he says it runs along an inground pool it just makes avoidance that much worse.


You are correct


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## WronGun (Oct 18, 2013)

So using the 1507 it looks like I would meg all 3 conductors @100v ?


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## MechanicalDVR (Dec 29, 2007)

WronGun said:


> So using the 1507 it looks like I would meg all 3 conductors @100v ?
> 
> 
> Sent from my iPhone using Tapatalk


For a UF like that I'd use 500v.


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## splatz (May 23, 2015)

WronGun said:


> So using the 1507 it looks like I would meg all 3 conductors @100v ?
> 
> 
> Sent from my iPhone using Tapatalk


I'd test hot to ground and neutral to ground starting at 50V, see what you see, work up to 500v if necessary to see something. (If you're not seeing a path at 500V, step back and regroup.)


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## HackWork (Oct 2, 2009)

WronGun said:


> If there was an issue wouldn't that mean that 2 wires were compromised , or 1 wire was compromised and touching the G.
> 
> Also , would it even be safe to use the bare ground as a H?
> 
> ...


I didn't realize it was UF cable with a bare ground.

The issue you have now is that the insulation on the hot wire is compromised and leaking current to ground.

If you had wire in pipe which was all insulated, you could switch that wire with the poor insulation to the grounding comductor as a quick fix.

But it won't work for you.


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## nrp3 (Jan 24, 2009)

The megger will confirm whether the cable is bad or not. I suggest trying it out on a known good piece of romex or UF. What I usually see is a nice steady rise into the gig range with my megger (MIT420). Bad segments show unsteady rise to a much lower value. 

Now that we know it's bad, you need to find the bad spot. Different gear for that. You locate the route, then fault locate. Sometimes it's just quicker and easier to dig and replace with conduit. 

I have to find a solid fault somewhere in 100 yards of 12-3 this weekend. This one shows continuity, should make it easier to find. Out there somewhere.


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## WronGun (Oct 18, 2013)

nrp3 said:


> The megger will confirm whether the cable is bad or not. I suggest trying it out on a known good piece of romex or UF. What I usually see is a nice steady rise into the gig range with my megger (MIT420). Bad segments show unsteady rise to a much lower value.
> 
> Now that we know it's bad, you need to find the bad spot. Different gear for that. You locate the route, then fault locate. Sometimes it's just quicker and easier to dig and replace with conduit.
> 
> I have to find a solid fault somewhere in 100 yards of 12-3 this weekend. This one shows continuity, should make it easier to find. Out there somewhere.




But what am I looking for ? Again I'm
Comparing this to my experience running MI cable tests..We would have a manual that showed us acceptable readings for the cable we were testing which didn't always Read 0 due to the mineral in the cable which would allow acceptable ranges due to moisture 

(Testing outter copper jacket with inner core and same with fire alarm MI outter copper jacket against core and shields) I would spend days Logging/reporting all different megger readings at various termination points.

I'm assuming with THHN should always shoot for 0. 


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## nrp3 (Jan 24, 2009)

You are looking for a very high resistance reading for a good cable. Like I said, take your new megger to a known piece of good cable. Take readings for l-n, l-g, and n-g. They should be all high resistance and similar. Now take a segment of cable and beat on it with a hammer and then take those same readings again.


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## telsa (May 22, 2015)

Any conductor that's tripping a GFCI ( at 120VAC L-N ) will SING for a megger.


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## frenchelectrican (Mar 15, 2007)

The other thing is what the distance from the breaker to the receptale location ?

Due some GFCI will trip with very long runs typically over 200 feet or so depending on how senstive it is .,,

if that was a short run then hack and few other guys posted a good suggest to do the trouble shooting. the other trick I would use is get pigtail socket and get indentscent bulb and hook it in series and see if the bulb glow bright or dim if dim then you got slow current leakage but getting bright then you got major issue.


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## macmikeman (Jan 23, 2007)

frenchelectrican said:


> The other thing is what the distance from the breaker to the receptale location ?
> 
> Due some GFCI will trip with very long runs typically over 200 feet or so depending on how senstive it is .,,
> 
> if that was a short run then hack and few other guys posted a good suggest to do the trouble shooting. the other trick I would use is get pigtail socket and get indentscent bulb and hook it in series and see if the bulb glow bright or dim if dim then you got slow current leakage but getting bright then you got major issue.


Man! I was going thru this thread and it was getting close to the end and still nobody was asking how far away is this shed and I was almost there , one poster still to go and I was gonna ask, and oh crap, a smart guy like me is there when I'm over visiting my granddaughter and I didn't get this one in...... It's probably a nick, but Frenchy is right on target with his thinking also. Seen this hundreds of times. Just do like Hax says and move the gfi out to the end , until at some point in time the nick becomes a boom. Then they be digging.


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## HackWork (Oct 2, 2009)

macmikeman said:


> Man! I was going thru this thread and it was getting close to the end and still nobody was asking how far away is this shed and I was almost there , one poster still to go and I was gonna ask, and oh crap, a smart guy like me is there when I'm over visiting my granddaughter and I didn't get this one in...... It's probably a nick, but Frenchy is right on target with his thinking also. Seen this hundreds of times. Just do like Hax says and move the gfi out to the end , until at some point in time the nick becomes a boom. Then they be digging.


I'm not the one who suggested to move the GFCI out to the shed.

How does the length of the run matter if it trips the GFCI with the other end of the run completely disconnected? If the length of the run was the cause, it would only trip while something was connected and running, right?


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## splatz (May 23, 2015)

WronGun said:


> But what am I looking for ? ... I'm assuming with THHN should always shoot for 0.





telsa said:


> Any conductor that's tripping a GFCI ( at 120VAC L-N ) will SING for a megger.


If the GFCI trips at 4ma current imbalance, then the high-resistance short has to be under 30Kohms. If it trips at 6ma current imbalance, 20Kohms. So anything over those values probably isn't your culprit. 

V/I=R
120/.004=30,000
120/.006=20,000 

Realistically it will probably stick out like a sore thumb when you test.


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## WronGun (Oct 18, 2013)

The shed is about 40'-50' away from the gfci

This will be a learning experience , megger will be here Friday ...

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## nrp3 (Jan 24, 2009)

It always is. Just because you have the cool tools, doesn't mean you don't have to learn how to use them. Tracers, locators, meggers, all that. Most don't get you what you need without a little experience. You should be able to see right away in this scenario whether the wire is bad or not, especially if you've experimented first.


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## RePhase277 (Feb 5, 2008)

HackWork said:


> I'm not the one who suggested to move the GFCI out to the shed.
> 
> How does the length of the run matter if it trips the GFCI with the other end of the run completely disconnected? If the length of the run was the cause, it would only trip while something was connected and running, right?


Not necessarily. There is no such thing as an insulator, just conductors with different conductivities. There is a tiny leakage current through the insulation all the time. You could consider the insulation as a small load. There is also a current flowing due to capacitance. Over a long enough distance those currents could get large enough to trip a GFI...

But that would be some run. Hundreds of feet.


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## HackWork (Oct 2, 2009)

RePhase277 said:


> Not necessarily. There is no such thing as an insulator, just conductors with different conductivities. There is a tiny leakage current through the insulation all the time. You could consider the insulation as a small load. There is also a current flowing due to capacitance. Over a long enough distance those currents could get large enough to trip a GFI...
> 
> But that would be some run. Hundreds of feet.


What you say might be true, but I don't buy it here.

_In the situation at hand_ of this residnetial run of UF to the shed, the GFCI is only going to trip due to too long of a run if the other end has a load on it. I believe Frenchie missed the part about it being disconnected.


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## RePhase277 (Feb 5, 2008)

HackWork said:


> What you say might be true, but I don't buy it here.
> 
> _In the situation at hand_ of this residnetial run of UF to the shed, the GFCI is only going to trip due to too long of a run if the other end has a load on it. I believe Frenchie missed the part about it being disconnected.


I agree that in this instance capacitance isn't the problem. If it were, it always would have been. I'm just talking theory here.


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## MechanicalDVR (Dec 29, 2007)

HackWork said:


> I'm not the one who suggested to move the GFCI out to the shed.
> 
> How does the length of the run matter if it trips the GFCI with the other end of the run completely disconnected? If the length of the run was the cause, it would only trip while something was connected and running, right?


YES, and I took it from the OP that this was something that had been functional and just went bad not that it was new and didn't work from the get go.

After further posts I think the UF was nicked with a shovel during the installation of the inground pool.


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## Drsparky14 (Oct 22, 2016)

HackWork said:


> WronGun is a contractor and seems to be doing well so I say just go for the Fluke.
> 
> What's the difference between the 1503 and 1507?




4


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## HackWork (Oct 2, 2009)

Drsparky14 said:


> 4
> 
> 
> Sent from my iPhone using Tapatalk


You're 2 pages late, and 3 dollars short...



drewsserviceco said:


> 0004


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## just the cowboy (Sep 4, 2013)

WronGun said:


> I'm assuming with THHN should always shoot for 0.
> 
> 
> Sent from my iPhone using Tapatalk


Think of the name Megger you are lookig for MEG ohms in the 100s.

Have fun with new toy, hold leads to check.


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## RePhase277 (Feb 5, 2008)

WronGun said:


> I'm assuming with THHN should always shoot for 0.
> 
> 
> Sent from my iPhone using Tapatalk


Zero ohms would be bad. This thing is testing the resistance of the insulation, not the conductor. You want insulation resistance as close to infinite as possible.


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## MechanicalDVR (Dec 29, 2007)

just the cowboy said:


> Think of the name Megger you are lookig for MEG ohms in the 100s.
> 
> *Have fun with new toy, hold leads to check.*


This is why God made apprentices!


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## drspec (Sep 29, 2012)

In a case like this, a Greenlee cable locator, Greenlee pulse ground fault locator, a short piece of UF and 2 direct bury UF splice kits will make you some quick easy money. 
I LOVE finding and repairing these types of faults.


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## nrp3 (Jan 24, 2009)

I make good coin with this too. Sometimes it's so badly messed up that it needs replacement, but you look like genius when you find and fix it.


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## drewsserviceco (Aug 1, 2014)

drspec said:


> In a case like this, a Greenlee cable locator, Greenlee pulse ground fault locator, a short piece of UF and 2 direct bury UF splice kits will make you some quick easy money.
> I LOVE finding and repairing these types of faults.



Is that aka a thumper? Heard stories of trying to locate a fault in underground high voltage cable and the locator used a thumper while walking around barefoot. Maybe just jobsite BS, but isn't any more fantastical than seeing someone use witching sticks for the first time...


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## scotch (Oct 17, 2013)

drewsserviceco said:


> Is that aka a thumper? Heard stories of trying to locate a fault in underground high voltage cable and the locator used a thumper while walking around barefoot. Maybe just jobsite BS, but isn't any more fantastical than seeing someone use witching sticks for the first time...


Certainly using a "thumper " will find a fault.....if it doesn't cause it first ! That HV discharge puts an end to many cables if in the wrong hands !
A megger isn't quite as destructive if you are learning to use it . Unless you're the apprentice holding the leads of course ....always a learning experience.


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## MechanicalDVR (Dec 29, 2007)

scotch said:


> Certainly using a "thumper " will find a fault.....if it doesn't cause it first ! That HV discharge puts an end to many cables if in the wrong hands !
> A megger isn't quite as destructive if you are learning to use it . Unless you're the apprentice holding the leads of course ....*always a learning experience*.


Not to mention fun to watch!


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## drewsserviceco (Aug 1, 2014)

scotch said:


> Certainly using a "thumper " will find a fault.....if it doesn't cause it first ! That HV discharge puts an end to many cables if in the wrong hands !
> 
> A megger isn't quite as destructive if you are learning to use it . Unless you're the apprentice holding the leads of course ....always a learning experience.



I appreciate your comment and can certainly see cable destruction as imminent in the wrong hands. I've never used one and only heard of them. 

I was wondering if the one of the greenlee tools mentioned in the post I quoted was indeed a thumper but I wasn't necessarily comparing a thumper to a megger. 

To the OP, since I never really commented, I have the Fluke 1507 and am very happy with it. I don't have a ton of experience in using it for some slick troubleshooting I have been able to use it for pass/fail testing after a lightning strike and more commonly to check my own work before energizing cable/equipment. Having it and using it would have been ideal in a scenario such as his, the wire is either good or has failed/ is failing. The amount of time one can save with a simple test will quickly pay for the tester.


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## LARMGUY (Aug 22, 2010)

HackWork said:


> WronGun is a contractor and seems to be doing well so I say just go for the Fluke.
> 
> What's the difference between the 1503 and 1507?


http://assets.fluke.com/manuals/1507____umeng0000.pdf


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## drspec (Sep 29, 2012)

drewsserviceco said:


> Is that aka a thumper? Heard stories of trying to locate a fault in underground high voltage cable and the locator used a thumper while walking around barefoot. Maybe just jobsite BS, but isn't any more fantastical than seeing someone use witching sticks for the first time...


 
http://www.greenlee.com/products/PULSE%40dGROUND-FAULT-LOCATOR.html?product_id=18006

Identifies the exact location of even the smallest breaks in insulation by "pulsing" a high-voltage signal that radiates into the earth at the location of the faults. With the A-frame mounted receiver, a visual analog meter points the way to the source of the voltage
Multiple faults on a single wire can be identified indicating the need to replace instead of repair


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## nrp3 (Jan 24, 2009)

Thumper is a different thing entirely. What we're using here is a something that finds the point at which the current from the transmitter leaks to earth. The thumper, as I understand it, is used for high voltage cables makes an arc and noise at the point of the fault and microphones are used to pinpoint the location. TDR can be used as well.


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## HackWork (Oct 2, 2009)

WronGun, read this: A Stitch In Time


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## Helmut (May 7, 2014)

Sell them on installing a new line in PVC, and be done.

Nix the test equipment and repair ideas.


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## sbrn33 (Mar 15, 2007)

Just go get one oof these. Takes some practice but just like spec said it is fun as hell when you find the problem. 
https://www.amazon.com/Greenlee-501-Tracker-Cable-Locator/dp/B001GHZP24


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## MechanicalDVR (Dec 29, 2007)

Helmut said:


> Sell them on installing a new line in PVC, and be done.
> 
> Nix the test equipment and repair ideas.


Yeah, sometimes common sense needs to take over.

The kid needs a megger but we already know the UF needs to be abandoned in place and replaced.


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## macmikeman (Jan 23, 2007)

If you guy's didn't have pissed off 480sparky he would have driven his tractor over there and fixed it for free with his locator as part of a community service for the royal order of polar bears.


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## MechanicalDVR (Dec 29, 2007)

macmikeman said:


> If you guy's didn't have pissed off 480sparky he would have driven his tractor over there and fixed it for free with his locator as part of a community service for the royal order of polar bears.


Ahh, such is life!

If that first apple was never eaten from that bad tree..................


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## sbrn33 (Mar 15, 2007)

MechanicalDVR said:


> Ahh, such is life!
> 
> If that first apple was never eaten from that bad tree..................


Who says that apple didn't taste great. Sometime it is worth it.


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## sbrn33 (Mar 15, 2007)

I put UF in all the time. Sometimes it is just the way to go. You guys act like pvc is the cure all/answer to everything. Some one driving a fence post goes thru pvc just as easy and it is waaay harder to repair.


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## HackWork (Oct 2, 2009)

sbrn33 said:


> I put UF in all the time. Sometimes it is just the way to go. You guys act like pvc is the cure all/answer to everything. Some one driving a fence post goes thru pvc just as easy and it is waaay harder to repair.


I only put rigid underground.


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## sbrn33 (Mar 15, 2007)

HackWork said:


> I only put rigid underground.


I see what you did right there.


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## macmikeman (Jan 23, 2007)

sbrn33 said:


> I see what you did right there.



Nothing wrong with rigid as long as he megger's it afterwards.


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## sbrn33 (Mar 15, 2007)

macmikeman said:


> Nothing wrong with rigid as long as he megger's it afterwards.


Meggers are for people that do not know how to trouble shoot.


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## HackWork (Oct 2, 2009)

sbrn33 said:


> I see what you did right there.


Do you? Cause I missed it :blink:


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## HackWork (Oct 2, 2009)

sbrn33 said:


> Meggers are for people that do not know how to trouble shoot.


Bologna.


Meggers are for shocking apprentices.


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## MechanicalDVR (Dec 29, 2007)

sbrn33 said:


> Who says that apple didn't taste great. Sometime it is worth it.


Of course the apple tasted great I'm sure, but rules are rules.


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## MechanicalDVR (Dec 29, 2007)

sbrn33 said:


> I put UF in all the time. Sometimes it is just the way to go. You guys act like pvc is the cure all/answer to everything.* Some one driving a fence post *goes thru pvc just as easy and it is waaay harder to repair.


Or a ground rod....... :whistling2:


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## MechanicalDVR (Dec 29, 2007)

sbrn33 said:


> Meggers are for people that do not know how to trouble shoot.


Really? 

When you can find a motor winding starting to go bad without one let us all know.


----------



## MechanicalDVR (Dec 29, 2007)

HackWork said:


> Bologna.
> 
> 
> Meggers are for shocking apprentices.


I've had dumb, lazy, smart, and crazy apprentices but never a shocking one!


----------



## LARMGUY (Aug 22, 2010)

I've got an old hand cranked Biddle Megger.

Sounds like a personal problem doesn't it?

:lol:


----------



## MechanicalDVR (Dec 29, 2007)

LARMGUY said:


> I've got an old hand cranked Biddle Megger.
> 
> Sounds like a personal problem doesn't it?
> 
> :lol:


No, just a great play toy!


----------



## drspec (Sep 29, 2012)

Helmut said:


> Sell them on installing a new line in PVC, and be done.
> 
> Nix the test equipment and repair ideas.


why spend a full day trenching, installing PVC and pulling new wire when you can make the same amount of profit in 2 hours with a fault locator and move onto the next job?


----------



## nrp3 (Jan 24, 2009)

Sometimes when you find the first fault and meg both directions and find its still junky, maybe the digging up may be worth it. Depends on the situation.


----------



## Helmut (May 7, 2014)

drspec said:


> why spend a full day trenching, installing PVC and pulling new wire when you can make the same amount of profit in 2 hours with a fault locator and move onto the next job?


Why spend the money on a fault locator and megger, when you know the UF is bad?


----------



## trentonmakes (Mar 21, 2017)

Helmut said:


> Why spend the money on a fault locator and megger, when you know the UF is bad?


I see the benefits of it, especially if you do alot of service calls. The post you quoted spells it out nicely[emoji106]



ANSWERE THE QUESTION STEVIE!


----------



## sbrn33 (Mar 15, 2007)

MechanicalDVR said:


> Really?
> 
> When you can find a motor winding starting to go bad without one let us all know.


I don't remember the OP talking about checking a motor. Pretty sure he was doing a basic residential service call. Checking motors is completely different.


----------



## sbrn33 (Mar 15, 2007)

HackWork said:


> WronGun, read this: A Stitch In Time


Once again that has nothing to do with this situation.


----------



## HackWork (Oct 2, 2009)

drspec said:


> why spend a full day trenching, installing PVC and pulling new wire when you can make the same amount of profit in 2 hours with a fault locator and move onto the next job?


I don't see how that's realistic.


----------



## HackWork (Oct 2, 2009)

sbrn33 said:


> HackWork said:
> 
> 
> > WronGun, read this: A Stitch In Time
> ...


I recommended a good book on meggering to the OP who just bought a megger. WTF?

You don't know me, boy. You really want to fu*k with this?


----------



## trentonmakes (Mar 21, 2017)

HackWork said:


> I don't see how that's realistic.


Not sure on the profit but agree on easier less labor intensive

ANSWERE THE QUESTION STEVIE!


----------



## sbrn33 (Mar 15, 2007)

HackWork said:


> I recommended a good book on meggering to the OP who just bought a megger. WTF?
> 
> You don't know me, boy. You really want to fu*k with this?


That was not what this thread was about. Quit derailing it. 

Don't you dare try to intimidate me. We both know I am smarter and better looking. The only thing you have going over me is a really nice truck.


----------



## HackWork (Oct 2, 2009)

trentonmakes said:


> Not sure on the profit but agree on easier less labor intensive
> 
> ANSWERE THE QUESTION STEVIE!


Of course it's less labor intensive. But it's also a tiny job compared to a big one. So to say that you can make the same thing is kinda crazy. 

And if it does end up costing the same for 2 hours worth of work vs. 2 days, why would the customer go along with it instead of just having the new line put in?


----------



## HackWork (Oct 2, 2009)

sbrn33 said:


> That was not what this thread was about. Quit derailing it.
> 
> Don't you dare try to intimidate me. We both know I am smarter and better looking. The only thing you have going over me is a really nice truck.


You'll be receiving a very sternly worded text from me later in the day.


----------



## sbrn33 (Mar 15, 2007)

HackWork said:


> You'll be receiving a very sternly worded text from me later in the day.


Big golf tourny today. I won't read it till about 5 and even then I will be lit.


----------



## MechanicalDVR (Dec 29, 2007)

sbrn33 said:


> I don't remember the OP talking about checking a motor. Pretty sure he was doing a basic residential service call. Checking motors is completely different.


But you comment encompassed way more than the OP:



sbrn33 said:


> Meggers are for people that do not know how to trouble shoot.


It took it as you painting with a overly large brush.


----------



## MechanicalDVR (Dec 29, 2007)

trentonmakes said:


> I see the benefits of it, especially if you do alot of service calls. The post you quoted spells it out nicely[emoji106]
> 
> 
> 
> ANSWERE THE QUESTION STEVIE!


One with "a lot of service calls" under their belt would have had it repaired already.

The OP is new to being out there on his own.

Rather than dump a ton of money on various test equipment, dig it up and replace it, collect your money and build a surplus for new toys that aren't 100% necessary at this stage of the game.


----------



## Going_Commando (Oct 1, 2011)

MechanicalDVR said:


> trentonmakes said:
> 
> 
> > I see the benefits of it, especially if you do alot of service calls. The post you quoted spells it out nicely
> ...


Dig it up and replace it? F that noise. Trench, rum pvc, and abandon that uf in place.


----------



## MechanicalDVR (Dec 29, 2007)

Going_Commando said:


> Dig it up and replace it? F that noise. Trench, rum pvc, and abandon that uf in place.


I'm all for the abandon part, the pvc is optional. 

That UF if done right and devoid of new construction (pool) would last a very long time.


----------



## nrp3 (Jan 24, 2009)

The new UF, while much easier to strip (the grey stuff), seems fragile compared to the older stuff with seemingly thicker jacket. I spent a bunch of time trying to find some faults out by Worcester in the spring. Some of the run was T spliced in the ground so you couldn't isolate the segments like you normally would. Picked up the phone, called the office and brought in an excavator. Had that trench dug very quickly with pvc going right back in. Found all the faults along the way. At least three, wasn't worth repairing in that instance. Not cheap, but those segments are not likely to fail again. I have two more to deal with. One is at least 100 plus yards. That one should be fixed if possible. That is if I can locate the actual route. The next one is fairly short and they think the landscapers drove a post through it lately. We'll see.


----------



## Jack Legg (Mar 12, 2014)

Helmut said:


> Why spend the money on a fault locator and megger, when you know the UF is bad?


you need to move it 5' away from the pool anyway

If I knew it ran right beside the pool, I would stop right there and give the HO a price for relocation. I wouldn't repair it


----------



## Jack Legg (Mar 12, 2014)

WronGun said:


> Definitely going for the fluke, and this UF runs alongside an underground pool, definitely not doing anything shady.
> 
> 
> Sent from my iPhone using Tapatalk


remember, don't do anything shady like leave uf alongside the pool


----------



## telsa (May 22, 2015)

Jack Legg said:


> remember, don't do anything shady like leave uf alongside the pool


I'd fear that the fault is under the new hardscape laid down by the pool crew.

Note also, they drive a LOT of stakes during form up.


----------



## nrp3 (Jan 24, 2009)

Did they change the proximity rule for pools in the 17?


----------



## WronGun (Oct 18, 2013)

I've had my hand in the manual trying to learn this tool.... I have another job Tomorrow I need it for, so I have some things to learn tonight.

I've been running insulation tests with romex... recording numbers 

Then smashing , slicing the cable only to get the same readings on a retest, I'm doing something wrong apparently










Sent from my iPhone using Tapatalk


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## MechanicalDVR (Dec 29, 2007)

telsa said:


> i'd fear that the fault is under the new hardscape laid down by the pool crew.
> 
> Note also, they drive a lot of stakes during form up.


That is why you plot out a new route and leave the old crap right where it is.


----------



## MechanicalDVR (Dec 29, 2007)

WronGun said:


> I've had my hand in the manual trying to learn this tool.... I have another job Tomorrow I need it for, so I have some things to learn tonight.
> 
> I've been running insulation tests with romex... recording numbers
> 
> ...


Slicing dry romex isn't going to show much, now stick that sliced romex in the ground (water with mineral content) and see the reading you'll get.

Open air is more insulator than conductor.


----------



## WronGun (Oct 18, 2013)

Well for tomorrows job it would b nice to see if the wire or equipment is bad ... because we aren't getting clear readings with the basic tools as to why we are getting a trip 


Sent from my iPhone using Tapatalk


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## splatz (May 23, 2015)

Try wetting the smashed up part where you hammered on it, see if that makes a difference. 

Staple it to a scrap of 2x4 and keep smashing the **** out of the staple, you'll see something.


----------



## nrp3 (Jan 24, 2009)

What are you seeing for a reading for good romex?


----------



## dronai (Apr 11, 2011)

WronGun said:


> Well for tomorrows job it would b nice to see if the wire or equipment is bad ... because we aren't getting clear readings with the basic tools as to why we are getting a trip
> 
> 
> Sent from my iPhone using Tapatalk


Who cares, prove that the wire is damaged, and run a new one. Think $$$


----------



## splatz (May 23, 2015)

WronGun said:


> Well for tomorrows job it would b nice to see if the wire or equipment is bad ... because we aren't getting clear readings with the basic tools as to why we are getting a trip


I certainly agree with you @WronGun, don't listen to these knuckle dragging megger haters. 

If two different GFCI's are CI-ing then you probably have a GF. If it happens with the end of the UF cable isolated, it's a pretty safe bet there's a ground fault in the cable. But you're not sure. 

You went to verify that guess with a continuity tester but it didn't give you a conclusive result. In my opinion you need to verify the guess before you dig up someone's lawn. _This is the exact right point to bring in the megger._ 

If you don't have one, the day you need one to do the job the right way is the right day to buy it. 

I 'd do exactly what you're doing. 

As for running new or whatever - I might follow the UF and rip it out in the process and follow the same path unless it's a ridiculous route. If it was laid while the pool was being built they might know things about what's in the ground that you don't.


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## HackWork (Oct 2, 2009)

splatz said:


> I certainly agree with you @WronGun, don't listen to these knuckle dragging megger haters.


Yeah, I hate those guys!


----------



## WronGun (Oct 18, 2013)

dronai said:


> Who cares, prove that the wire is damaged, and run a new one. Think $$$


This is another job on tomorrow's schedule , not the UF job.

It's brand new ! This is the finish part of a large rough. I would rather prove the drywall guy F'd up the wire... also I'd like to prove this before I go out and buy a new 8' baseboard heater....

This ideally is the perfect scenario 

Prove the drywall banged it up and save me from lugging around an 8' baseboard heater


Sent from my iPhone using Tapatalk


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## nrp3 (Jan 24, 2009)

By the way, there are a few you tube videos out there on megger testing. I haven't picked out one yet that best conveys what I and others are trying to show you. I can't post any photos or videos, now that photo bucket is pay for service. Video would be best, just don't know how to do it.


----------



## sbrn33 (Mar 15, 2007)

here is your answer. 
https://www.amazon.com/Supco-M500-I...ie=UTF8&qid=1503836453&sr=8-4&keywords=megger


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## sbrn33 (Mar 15, 2007)

telsa said:


> I'd fear that the fault is under the new hardscape laid down by the pool crew.
> 
> Note also, they drive a LOT of stakes during form up.


That is exactly where it is at.


----------



## nrp3 (Jan 24, 2009)

Quite possibly and may be a driving factor in just abandoning it and going right to pvc. Having the tool is great for next time. I can't see the routing so I'm just speculating.


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## WronGun (Oct 18, 2013)

sbrn33 said:


> That is exactly where it is at.




At this point it's all about replacement , but here's my chance to learn this tool. It's also nice to be able to give the client a visual/definite cause to the issue.


Sent from my iPhone using Tapatalk


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## nrp3 (Jan 24, 2009)

The Supco model is best for that. I don't have one, but people take my word for it when my Megger says it's bad.


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## HackWork (Oct 2, 2009)

nrp3 said:


> The Supco model is best for that. I don't have one, but people take my word for it when my Megger says it's bad.


The Supco looks like a gimmick. If I had to use it to get my customers to trust me, I already lost.

WronGun, you're on the right path. That Fluke will last you your entire career.


----------



## splatz (May 23, 2015)

sbrn33 said:


> here is your answer.
> https://www.amazon.com/Supco-M500-I...ie=UTF8&qid=1503836453&sr=8-4&keywords=megger


If I am trying to prove the wire is bad and that's what's tripping the GFCI I'd want something with a lower range. The indicator lights on the supco start at 20Mohms. To trip the GFCI, I believe the fault will have to be less than 30Kohms at the operating voltage. The Supco only tests at 500V. So his money was well spent.


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## telsa (May 22, 2015)

telsa said:


> I'd fear that the fault is under the new hardscape laid down by the pool crew.
> 
> Note also, they drive a LOT of stakes during form up.


BTW, I seriously doubt that the UF was EVER run 18" down.

GFCI says to me that its a cheesy 9" down... even LESS when the hardscape crew backed off the topsoil.

12" of cover -- 'tis to dream.

Such backyard projects pass un-inspected... but, of course.


----------



## HackWork (Oct 2, 2009)

I knew I would get splatz to like me again.


----------



## MechanicalDVR (Dec 29, 2007)

WronGun said:


> At this point it's all about replacement , but here's my chance to learn this tool. It's also nice to be able to give the client a visual/definite cause to the issue.
> 
> 
> Sent from my iPhone using Tapatalk


The Supco megger is the best one to give a client a visual.

Were as you as a licensed electrician were confused as to the reading you should see on a bad wire, the Supco takes all the guess work out of the equation and says "Good" - "Caution" - "Bad" right on the face of the meter clear as day.

It makes a great sales aid.


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## MechanicalDVR (Dec 29, 2007)

nrp3 said:


> The Supco model is best for that. I don't have one, but people take my word for it when my Megger says it's bad.


Buy the old model off ebay or something.










It provides a visual for "my meter says it's bad".


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## lighterup (Jun 14, 2013)

sbrn33 said:


> here is your answer.
> https://www.amazon.com/Supco-M500-I...ie=UTF8&qid=1503836453&sr=8-4&keywords=megger


$84.00 ? that's all?


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## MechanicalDVR (Dec 29, 2007)

lighterup said:


> $84.00 ? that's all?


I've seen the older model for $20 at flea markets.


----------



## WronGun (Oct 18, 2013)

splatz said:


> Try wetting the smashed up part where you hammered on it, see if that makes a difference.
> 
> Staple it to a scrap of 2x4 and keep smashing the **** out of the staple, you'll see something.




I'm still playing with this thing. The wire In my hand is looks like it went through a grinder and I'm getting the same readings as the brand new wire im also testing .......Confused 

It's obvious the insulation is compromised , yet the meter doesn't know it ?!

The YouTube videos aren't the greatest 

Sent from my iPhone using Tapatalk


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## lighterup (Jun 14, 2013)

Jack Legg said:


> you need to move it 5' away from the pool anyway
> 
> If I knew it ran right beside the pool, I would stop right there and give the HO a price for relocation. I wouldn't repair it


Our CBO has spec for pools and does not allow UF. It all has to be in pvc.
Voltage leakage through insualtion is probably why


----------



## HackWork (Oct 2, 2009)

WronGun said:


> I'm still playing with this thing. The wire In my hand is looks like it went through a grinder and I'm getting the same readings as the brand new wire im also testing .......Confused
> 
> It's obvious the insulation is compromised , yet the meter doesn't know it ?!
> 
> ...


No megger can tell if a wire insulation is damaged. What the megger will tell you is if current is flowing to somewhere that it shouldn't be flowing.

Think of open air conductors. They are perfectly safe as long as they aren't touching anything or each other, right?

So now back to your cable. You can strip insulation off of the cable and it will still be fine as long as nothing is touching it. But as soon as it comes in contact with something metal, another conductor, or moisture... you will have an issue.

Try this test: Submerge 2 piece of romex into water, one normal with good insulation and one with broken insulation. This is more like what is happening with your underground UF cable.

Or like someone else mentioned, hammer a piece of romex to a board with a staple and tighten it down too hard so that it breaks the insulation to symbolize what might happen when roughing in romex.


----------



## WronGun (Oct 18, 2013)

HackWork said:


> No megger can tell if a wire insulation is damaged. What the megger will tell you is if current is flowing to somewhere that it shouldn't be flowing.
> 
> Think of open air conductors. They are perfectly safe as long as they aren't touching anything or each other, right?
> 
> ...




This is where im confused... if this was the case wouldn't my fluke T600 pick up continuity 


Sent from my iPhone using Tapatalk


----------



## HackWork (Oct 2, 2009)

WronGun said:


> This is where im confused... if this was the case wouldn't my fluke T600 pick up continuity
> 
> 
> Sent from my iPhone using Tapatalk


First, I edited my post a bit.

Second, the answer to this question is in my first post. 

It's such a tiny amount of current that is flowing that it's not enough to set off your continuity tester. A GFCI only needs a very small amount of current to trip, not nearly enough for a continuity tester to pickup.

Think of a megger as a very powerful continuity tester that will work on more sensitive leakage.


----------



## WronGun (Oct 18, 2013)

Ok well my test cable aside , as soon as I get back to this job and test this tripping UF I should most definitely get some different readings 

Just figured this smashed up
And sliced up romex should've given me some funny readings 


Sent from my iPhone using Tapatalk


----------



## HackWork (Oct 2, 2009)

WronGun said:


> Ok well my test cable aside , as soon as I get back to this job and test this tripping UF I should most definitely get some different readings
> 
> Just figured this smashed up
> And sliced up romex should've given me some funny readings
> ...


It's all science, there's an explanation behind it.

Why would a sliced up romex give a funny reading? 

The answer is because current is flowing, either thru touching conductors, a metal staple, moisture, etc. 

You haven't introduced those things into your test cable.


----------



## MechanicalDVR (Dec 29, 2007)

WronGun said:


> This is where im confused... if this was the case wouldn't my fluke T600 pick up continuity
> 
> 
> Sent from my iPhone using Tapatalk


No!

Try the staple test, bang the staple in until it mars the jacket of the romex and take a reading with both the megger and your ohm meter.

Rap the staple again and reread.

Keep going and you will reach a point that the megger picks up the short and the ohm meter won't.


----------



## telsa (May 22, 2015)

WronGun said:


> Ok well my test cable aside , as soon as I get back to this job and test this tripping UF I should most definitely get some different readings
> 
> Just figured this smashed up
> And sliced up romex should've given me some funny readings
> ...



I hate to tell you, but even pinched conductors can suffice.

The grounding//bonding conductor runs right down the center.

Think about it.

But does it really matter ?

The odds favor that the flatwork// hardscape crew snagged shallow UF during formwork. 

It would be at that time that most of the top soil would've been scraped back.

In soft ground, the landscaping crew is going to drive their stakes deep.

The old trench will positively seem to be _soft ground_ to the flatwork crew.

This is something that electricians usually can't imagine. 

We just don't think in terms of maniacs driving stakes all through our trenches.

The advantage of PVC is that there is _some_ possibility that a stake will be deflected.


----------



## macmikeman (Jan 23, 2007)

Has is making fun of my Supco 500 so he has just landed on the go directly to jail square and doesn't get to pay 200 until he gets all the way around the board again.


----------



## HackWork (Oct 2, 2009)

macmikeman said:


> Has is making fun of my Supco 500 so he has just landed on the go directly to jail square and doesn't get to pay 200 until he gets all the way around the board again.


As splatz said, it wouldn't even have worked in this situation for the OP.


----------



## macmikeman (Jan 23, 2007)

HackWork said:


> As splatz said, it wouldn't even have worked in this situation for the OP.


I dispute that. The display shows 20 megs but it picks up way below that. I know how well it works from having checked with my real megger from Biddle against it many times just to make sure that the cheap ass looking thing really works. It does.


----------



## MTW (Aug 28, 2013)

I'd like to buy a digital megohm meter in addition to my Supco. Any suggestions?


----------



## MechanicalDVR (Dec 29, 2007)

MTW said:


> I'd like to buy a digital megohm meter in addition to my Supco. Any suggestions?


I have the Fluke 1537 and it's a great meter but at the same time I carry and use the little amprobe analog more for basic wiring.

All the Fluke's perform well.


----------



## macmikeman (Jan 23, 2007)

MTW said:


> I'd like to buy a digital megohm meter in addition to my Supco. Any suggestions?


Get the Fluke and pay extra for the warranty. Digital meters have displays. That is the weak spot. Although they are much more accurate than the old style analog meggers, the old style will last and last and last. The digital meters are defective once the display craps out. About ten years . Hopefully modern chips are getting better and they exceed that number, but I doubt it, since both Fluke and Megger need to keep selling meters . Anyway, Fluke is proven to outlast the other brands. So I would go there first.


----------



## MechanicalDVR (Dec 29, 2007)

macmikeman said:


> Get the Fluke and pay extra for the warranty. Digital meters have displays. That is the weak spot. Although they are much more accurate than the old style analog meggers, *the old style will last and last and last. The digital meters are defective once the display craps out*. About ten years . Hopefully modern chips are getting better and they exceed that number, but I doubt it, since both Fluke and Megger need to keep selling meters . Anyway, Fluke is proven to outlast the other brands. So I would go there first.


This is the reason I carry and use the analog more often.


----------



## MTW (Aug 28, 2013)

Ok, so Fluke digital seems like the way to go

Now, what about an old analog hand crank? I have opportunity to buy an NOS Amprobe one from a contractor I used to work for. I like the simplicity and durability of it as Mike says, but it's big and clunky.


----------



## HackWork (Oct 2, 2009)

macmikeman said:


> I dispute that. The display shows 20 megs but it picks up way below that. I know how well it works from having checked with my real megger from Biddle against it many times just to make sure that the cheap ass looking thing really works. It does.


That thing reminds me of the little project boxes we using in electronics class. I wonder if they have a customer fooler project I can put in one so I don't have to spend $84 on the Supco?


----------



## MTW (Aug 28, 2013)

HackWork said:


> That thing reminds me of the little project boxes we using in electronics class. I wonder if they have a customer fooler project I can put in one so I don't have to spend $84 on the Supco?





I used it to condemn an underground run of rigid that was in the slab and was tripping the breaker. The megger helped prove to me that it was the conduit at fault and not something else, and allowed me to go forward and rewire the circuit overhead.


----------



## HackWork (Oct 2, 2009)

MTW said:


> I used it to condemn an underground run of rigid that was in the slab and was tripping the breaker. The megger helped prove to me that it was the conduit at fault and not something else, and allowed me to go forward and rewire the circuit overhead.


Awesome. Just think of how great you can be if you replace that toy with a Fluke.


----------



## splatz (May 23, 2015)

WronGun said:


> I'm still playing with this thing. The wire In my hand is looks like it went through a grinder and I'm getting the same readings as the brand new wire im also testing .......Confused
> 
> It's obvious the insulation is compromised , yet the meter doesn't know it ?!
> 
> The YouTube videos aren't the greatest


I don't know if you tried my suggestion to spray the mangled wire with water, it will work better with dirty water or salt water - pure water isn't a good conductor. 

Just to prepare you, when these things are water related they can be a brutal pain in the ass to troubleshoot. You go out and spend big bucks on a megger, then you come back and there's no problem, looks fine on the megger, doesn't trip the GFCI. Well, it will next time it rains, and a little while after until the ground dries out. It can really run you in circles. 

With any luck the megger will be a better demo than the experiment you're mocking up


----------



## MechanicalDVR (Dec 29, 2007)

MTW said:


> Ok, so Fluke digital seems like the way to go
> 
> Now, what about an old analog hand crank? I have opportunity to buy an NOS Amprobe one from a contractor I used to work for. I like the simplicity and durability of it as Mike says, but it's big and clunky.


The small Amprobe is great for general diagnostic use.












If it has a high but bad range reading on a motor or compressor I will break out the Fluke to be positive before I recommend a replacement job.


----------



## splatz (May 23, 2015)

I am a fan of analog meters in general, I still break out the old Simpson once in a while. The main reason I like it is when you're looking for transient blips, the needle is easier to watch than the numbers. Easier to see what's going on. I will say I have no device I'm less likely to second guess the reading. 

I was told the rule of thumb for testing wiring installations is you test at double the system's voltage so the Amprobe, Supco, etc. testing at 500 is good for up to 240V circuits, if you're using it on 480V systems you'll want one that goes higher.


----------



## splatz (May 23, 2015)

HackWork said:


> I knew I would get splatz to like me again.


Not so fast. Did you buy us that fancy crimper I found?


----------



## HackWork (Oct 2, 2009)

splatz said:


> Not so fast. Did you buy us that fancy crimper I found?


No. I have decided that I would pay more than my originally set amount. But I am not going to pay $200. 

I need you to find a cheaper crimper along with the proper C-crimps for it.


----------



## HackWork (Oct 2, 2009)

splatz said:


> I am a fan of analog meters in general, I still break out the old Simpson once in a while. The main reason I like it is when you're looking for transient blips, the needle is easier to watch than the numbers. Easier to see what's going on. I will say I have no device I'm less likely to second guess the reading.
> 
> I was told the rule of thumb for testing wiring installations is you test at double the system's voltage so the Amprobe, Supco, etc. testing at 500 is good for up to 240V circuits, if you're using it on 480V systems you'll want one that goes higher.


I was told that you never test above the insulation rating so if you use the 500V setting on 300V insulation or 1,000V setting on 600V insulation you can damage it.


----------



## telsa (May 22, 2015)

HackWork said:


> I was told that you never test above the insulation rating so if you use the 500V setting on 300V insulation or 1,000V setting on 600V insulation you can damage it.


The NEMA standard for THHN is that it's tested for at least 600V + 1000V = 1,600V; automatically, by the factory. It's not supposed to roll out the door if it fails.

Elsewhere I've read that 2,000 Volts is the factory standard for THHN, etc.

It's de-rated for practical use.

I've seen THWN-2 used for 4160 VAC (L-L) as the feed for NEMA3R dry-type transformers. It had been in service for decades by the time I saw it. I was surprised. ( This set-up was being retired from service. )

The worry with meggers is if you should unwittingly pump this or that load with juice... and let some smoke out.


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## MechanicalDVR (Dec 29, 2007)

telsa said:


> The NEMA standard for THHN is that it's tested for at least 600V + 1000V = 1,600V; automatically, by the factory. It's not supposed to roll out the door if it fails.
> 
> Elsewhere I've read that 2,000 Volts is the factory standard for THHN, etc.
> 
> ...


That's the fudge factor engineers like to use t cover their own rears.


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## splatz (May 23, 2015)

HackWork said:


> I was told that you never test above the insulation rating so if you use the 500V setting on 300V insulation or 1,000V setting on 600V insulation you can damage it.





telsa said:


> The NEMA standard for THHN is that it's tested for at least 600V + 1000V = 1,600V; automatically, by the factory. It's not supposed to roll out the door if it fails.
> 
> Elsewhere I've read that 2,000 Volts is the factory standard for THHN, etc.
> 
> ...





MechanicalDVR said:


> That's the fudge factor engineers like to use t cover their own rears.


I would like to know the official word from Fluke or whoever on that. 

Of course we have extensively tested and know that apprentice fingers have insulation sufficient to tolerate megger testing.


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## WronGun (Oct 18, 2013)

A little update on the problem UF..

Even though it's being replaced I wanted to try out the megger, here are my readings










Sent from my iPhone using Tapatalk


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## MechanicalDVR (Dec 29, 2007)

WronGun said:


> A little update on the problem UF..
> 
> Even though it's being replaced I wanted to try out the megger, here are my readings
> 
> ...


Almost low enough for a good ohm meter.


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## Majewski (Jan 8, 2016)

I want that meter!!!


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## MechanicalDVR (Dec 29, 2007)

Majewski said:


> I want that meter!!!


Yeah it looks nice and simple.


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## A Little Short (Nov 11, 2010)

I have the same megger as Wrongun, including not taking the plastic off the display!


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## Majewski (Jan 8, 2016)

I'm going to get it with Bluetooth.


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## nrp3 (Jan 24, 2009)

The Megger MIT series has a analog as well as digital read out, so you can watch the needle and the digital display at the same time.


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