Barn breakers went bad after in house electric work

[PCustoms]

General Electric

You need to replace the Square D breakers with GE.

This could be your issue. If the breaker isn't correctly engaged to the buss, you (at best) might not get power through both legs.

Worst case is arcing and fire.

There are several incorrect breakers in that panel.

 

[sparky 1971]

My breaker is reading 240v across both lugs. At the shop, with the feeders disconnected from the breaker, I am now getting zero volts from one, and 120v on the other.

It's looking more and more like my cable has been damaged.

You need to replace the Square D breakers with GE.

This could be your issue. If the breaker isn't correctly engaged to the buss, you (at best) might not get power through both legs.

Worst case is arcing and fire.

There are several incorrect breakers in that panel.

He has 240 across the poles of the breaker. While it is a wrong breaker, that isn't the problem.

OP, I am assuming you have the wire sleeved where it goes underground at both ends. Did you put a bushing on the end of the conduit? If not, the wire may be bent tight against the end of the conduit and it rubbed through. I suppose it could rub through even if there is a bushing. I would start digging at the ends. Gotta start somewhere, right?

 

[PCustoms]

He has 240 across the poles of the breaker. While it is a wrong breaker, that isn't the problem.

OP, I am assuming you have the wire sleeved where it goes underground at both ends. Did you put a bushing on the end of the conduit? If not, the wire may be bent tight against the end of the conduit and it rubbed through. I suppose it could rub through even if there is a bushing. I would start digging at the ends. Gotta start somewhere, right?

Wouldn't it be possible to have enough of a connection to read @ the breaker, but get squat through several feet of wire?

Regardless if this is causing the issue, square d in a GE panel is not correct.

 

[sparky 1971]

Wouldn't it be possible to have enough of a connection to read @ the breaker, but get squat through several feet of wire?

Regardless if this is causing the issue, square d in a GE panel is not correct.

Probably not. If that were the case, the dead wire would have switched to the other side of the subpanel when he swapped the wires on the house breaker. He does have the wrong breakers, but that's another problem for another day.

 

[Wrench97]

If the same wire sayed dead after swapping at the breaker it has to be the wire.

 

[OptionalStop]

Thanks a lot for the advice here.. I may not have sleeved the cable as it passed through at the house, shame on me if I didn't. The weekend when the temps go up some I'm going to dig up at the house and look at the wire. I will update whatever I find. Best case is it is damaged there and I can pull the wire out, fix it, sleeve it properly and be done. And replace the breaker with the right one..

 

[sberry]

I just did one, not sure how long it had been there but it's the first I ever ran across. I suspect the owner damaged it a bit but we already had a trencher on the job and I wired new right around it. I might have looked if not for it was so easy to replace.

 

[Terry D]

What kind of wire did you use.

Is it in conduit inside the house and shop.

You do need to replace that breaker with the correct one, but that is not your problem for your lost leg here.

If you can get hold of a cable tracer, or have a contractor come out with one. You can hook it to the failed conductor and trace it to where you loose the signal. Do it from both ends. If you end up in the same spot, that is where you dig to repair it.

 

[Innovate1]

I would be inclined to unhook the wires at both ends and start doing continuity checks by shorting all the wires to the ground wire at the feed end and check for resistance on the garage end. I expect that will show one wire as open from what has been measured so far but how that might happen seems unlikely. If one is open a TDR (time domain reflectometer) is the perfect tool to find the location of the break before digging. Think they can be rented or if you have some electronics background and an oscilloscope you can put together one. I have done that a few times to locate breaks in low voltage wiring.

 

[bbbarracuda]

I am not an electrician, but a career of troubleshooting taught me that coincidences rarely happened. Look at what you did in the box to make sure you didn't cause your problem.
Often (usually) if it worked before you did the original work in the box, you caused it.

 

[Terry D]

I am not an electrician, but a career of troubleshooting taught me that coincidences rarely happened. Look at what you did in the box to make sure you didn't cause your problem.
Often (usually) if it worked before you did the original work in the box, you caused it.

When th OP was doing the electric work in his basement, he did it hot. He did not even go in the panel. Its been pretty well verified that one of the conductors on his feeder has failed. I agree with you about coincidences, but this time i believe this is just a rare occurrence. Nothing that he did in the house caused this.

Sent from my SM-G960U using The Garage Journal mobile app

 

[jabelding]

One thing I would do first is confirm that each of the wires in the sub panel go to the correct place to your main panel. Make sure leg 1 in main panel goes to leg 1 in sub neutral is neutral and leg 2 is leg 2 and the ground is good both ends. Without your wires marked in sub panel something could have gotten mixed up. Is your neutral in the sub panel separated from the ground? Is there a voltage between them? You could have the neutral mixed up.

 

[Denwood]

Kill power to the main panel, disconnect both legs (hots) at both house and shop. Wire nut hots together at your shop. Check for continuity between the two hots at your house. If none, you've positively confirmed a broken conductor. Check to make sure you have have no continuity between the hots and neutral. If you do, you have have a ground issue somewhere, or neutral is making contact with a hot somewhere in the buried line.

 

[grounded-b]

While you're at it - when the power is OFF. Remove the aluminum feeder conductors on both ends ( hots and neutral ) wire brush them and apply a No-OX compound to the wires before inserting them into the lugs.

This should have been done when the panel was installed. Aluminum will oxide over time. The aluminum oxide layer is non-conductive.

It is possible that this is why you had lost voltage out at the sub-panel.

Steve
JW Electrician

 

[Innovate1]

While you're at it - when the power is OFF. Remove the aluminum feeder conductors on both ends ( hots and neutral ) wire brush them and apply a No-OX compound to the wires before inserting them into the lugs.

This should have been done when the panel was installed. Aluminum will oxide over time. The aluminum oxide layer is non-conductive.

It is possible that this is why you had lost voltage out at the sub-panel.

Steve
JW Electrician

This is likely to be controversial and veering OT but is no-ox always needed at terminals? I understand that Aluminum oxidizes and it is probably best to put it on but is it really needed? The PoCo doesn't do it when they connect meter bases to the best of my knowledge. If the terminals are tightened properly it creates a gas tight seal at the points of contact which should prevent oxidation in the contact area.

 

[wyliesdiesels]

While you're at it - when the power is OFF. Remove the aluminum feeder conductors on both ends ( hots and neutral ) wire brush them and apply a No-OX compound to the wires before inserting them into the lugs.

This should have been done when the panel was installed. Aluminum will oxide over time. The aluminum oxide layer is non-conductive.

It is possible that this is why you had lost voltage out at the sub-panel.

Steve
JW Electrician

No-ox is actually only required if the manufacturer calls for it. Its not required by code and most manufacturers dont call for it so....