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I just can't justify putting this back together without at least a VOM ohm reading on the cables. Megger would be better.
Especially since a Supco M500 is really cheap and useful for more jobs coming up in the future.
 

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VICHY VC60B+ Digital Insulation Resistance Tester Megger MegOhmmeter Meter
It's only $37 I wonder if it's any good? It looks like a decent megger and has a nice display.
VICHY Megger on Ebay
The Supco M500 is quite affordable as well
 

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I like ceiling fans & EMT
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To help convince the customer about replacing the obviously damaged underground feeds, connect them without GFI protection and no loads connected in the shed and then take amperage readings on them.
I’m willing to bet they are drawing current and costing them money every day.
Was going to say this. I wouldnt want something connected that is leaking current, as a homeowner or as the serviceman.

This is a case for replacing the wires, disconnecting them, or, as a convoluted and possibly legal workaround, install a disconnect switch for the shed leads, remove the light switches in the sheds, and install GFCI's in the shed outlets. Not sure how close to the cost of new cable you would be by that point.
 

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Discussion Starter · #25 ·
Thanks to everyone for taking the time and responding to my question. I didn't respond sooner because I was away for a day or so. I have for sure read all of your comments and am thankful for all of them.
As I await getting my testers back I am going to shut every breaker off except the one for the circuit in question, I will make sure nothing is turned on or connected to that circuit. And I will see if the meter is turning. That should be an indicator.

thanks again

Joe
 

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Thanks to everyone for taking the time and responding to my question. I didn't respond sooner because I was away for a day or so. I have for sure read all of your comments and am thankful for all of them.
As I await getting my testers back I am going to shut every breaker off except the one for the circuit in question, I will make sure nothing is turned on or connected to that circuit. And I will see if the meter is turning. That should be an indicator.

thanks again

Joe
It only takes a greater than 6ma current leakage to trip a GFCI, you think a PoCo watt-hour meter will see that in a short time period?
 

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Discussion Starter · #27 ·
It only takes a greater than 6ma current leakage to trip a GFCI, you think a PoCo watt-hour meter will see that in a short time period?
No, but. As I stated, one of the 12/2s trips the GFCI instantly, the other it takes maybe three seconds. So I am hoping with the digital hydro meter, after some minutes something will change on the meter especially because one of the 12/2s trips instantly. I think its worth a shot until I get my testers back from a buddy of mine.
 

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Discussion Starter · #28 ·
Was going to say this. I wouldnt want something connected that is leaking current, as a homeowner or as the serviceman.

This is a case for replacing the wires, disconnecting them, or, as a convoluted and possibly legal workaround, install a disconnect switch for the shed leads, remove the light switches in the sheds, and install GFCI's in the shed outlets. Not sure how close to the cost of new cable you would be by that point.

I am with you 100%. The cost of the wire (and conduit which I always would have done regardless had I done the initial install) for sure pales by comparison to the cost of digging, probably 100 feet in total.
 

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Light Bender
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No, but. As I stated, one of the 12/2s trips the GFCI instantly, the other it takes maybe three seconds. So I am hoping with the digital hydro meter, after some minutes something will change on the meter especially because one of the 12/2s trips instantly. I think its worth a shot until I get my testers back from a buddy of mine.
Connect them without GFI protection to test and see the current lost.
 

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If both cables are bad, maybe they are damaged in a common area. Would it be worth it to grab a shovel where they go underground?
 

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That may end up being the plan. Thanks, Shocksystemsfor you time.
I don't think this is the way to go. You know there is an underground issue you are just masking it.
If it is as @eddy current said a shorted wire it will burn open sooner or later, after you said you fixed it.
 

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Tool Fetish
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VICHY VC60B+ Digital Insulation Resistance Tester Megger MegOhmmeter Meter
It's only $37 I wonder if it's any good? It looks like a decent megger and has a nice display.
VICHY Megger on Ebay
The Supco M500 is quite affordable as well
I'd check the differences between CAT II and CAT III test equipment. This is a CAT II tester. I just checked all of the test equipment that we have is rated at CAT III or above.
Just looked up CAT II; examples for usage from EC&M are appliances, portable tools and similar equipment. CAT III is for distribution circuits, fixed feeders and branch circuits.
Tool Fetish
 

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I like ceiling fans & EMT
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I would at least use an amp meter.
 

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Have you checked continuity between neutral and ground on the wires heading to shed? I've had the same problem where it wouldn't trip the breaker if I bypassed the GFCI but the GFCI would instantly trip. Turned out a siding screw had connected neutral and ground.
 

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Hackenschmidt
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Have you checked continuity between neutral and ground on the wires heading to shed? I've had the same problem where it wouldn't trip the breaker if I bypassed the GFCI but the GFCI would instantly trip. Turned out a siding screw had connected neutral and ground.
That's a good idea, but he swapped the underground with temporary wires across the ground and the issue went away, so I think he's isolated the problem to the underground wires.
 

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Hi all. I am stumped.

Yesterday I did a few minor updates on a home that was wired in the 80s.

I will try to be brief.

There is a (surface mount) receptacle on an outside wall of a home for a deck area, the deck is 30 ft x 30 ft and other than 30 feet away the deck it 100% closed in and water tight, under no circumstances can any snow or rain come anywhere near the receptacle, nor do they use this receptacle to plug in any power tools or anything else for use "off" of the deck.
Out of the top of the PVC receptacle box is 1/2 inch PVC conduit up to a water proof switch that feeds four light in the deck area. Coming out of the bottom of the surface mounted PVC receptacle box there are two, 12/2 NMWU wires that feed two sheds (via under the ground) in the back yard. Each shed has one receptacle and one light. Neither are GFCI protected. So I decided to replace the receptacle on the deck with a GFCI receptacle to protect the two sheds.
The bottom line? Once the GFCI receptacle was installed, it trips. Every time.... When I disconnect the two 12/2 NMWU wires that feed the sheds it doesn't trip, The GFCI operates fine as a receptacle and as a feed for the lights, but again, hook up the two 12/2 NMWU wires for the sheds,,,,,it trips.

I have carefully inspected the visible part of the 12/2's under the deck (before they go underground) and they are fine.
I inspected the 12/2 s from the entry points in the shed to where they enter a junction box, the wires are fine. I disconnected everything from the junction box except the incoming feed and capped off the wires and after doing so, still the GFCI on the deck trips.

There must be a short or something wrong under the ground between the deck and the sheds, no?
Also. I tried connecting the 12/2 NMWU's independently, one at a time, and once each one is connected by itself, the GFCI trips. The only difference is when I connect one of them to the GFCI it trips instantly, the other trips after about 3 seconds.

I am sorry this is such a long drawn out explanation but I wanted to give as much info as I could. It has to be a fault in the 12/2 under the ground, no?

Any ideas or suggestions will be much appreciated.

P.S. Everything works fine if the deck receptacle is not a GFCI.
With the deck receptacle standard, not GFCI, I temporarily, installed a GFCI receptacle in one of the sheds, and it works fine. (just some added info)
Replace all receptacles with GFCI. Pig tail each location that require to feed trough to the next. Make no receptacle dependent on the GFCI upstream.
 

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I hate to state the obvious, but whoever did the original work may not have had the best technique.
I look for razor cuts where the sheathing has been cut away. I don't know what the Canadian wire is like, but I've seen lots of slashes along conductors in UF -older wire in particular was hard to cut. I once got a free roll of UF from a customer's garage and it was so difficult to work with that I gave it to my scrapper. :-(

I also agree with whoever said that the wire may be damaged right below the receptacle box since both wires go underground there... Someone careless may have been digging or backfilling quickly with a shovel and hit the wires.

I doubt this is it, but while you have the receptacle taken apart I'd stick a new GFCI in there anyway just in case ... Really anything (legal) to avoid having to dig up the wires.

Sad as it is to say this: because it's outside and buried, I would not be satisfied with simply replacing all receptacles with GFCIs and leaving a cable that is potentially leaking current.

I don't deal with underground cable much because I live in a city, but I have seen squirrels and mice chew the F out of NM.

Your customer should be glad that you're being thoughtful about this. I hope they take it that way!
 
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