Thread: Scorched neutral question

What may have been the cause for this neutral to have gotten hot? At this point, all appears to be well in this 1964 house.
At first, I thought it may have been a seized compressor in the outdoor heat pump unit, as it has been turned off and is described in the listing as "decommissioned". But that is a 240 v circuit, so not likely to have overloaded the neutral, right?
I am wondering if a 120 v branch circuit breaker has failed to trip. Any ideas?

Are the neutral lugs on this Westinghouse panel rated for two wires?

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Originally Posted by John Kogel

What may have been the cause for this neutral to have gotten hot? At this point, all appears to be well in this 1964 house.
At first, I thought it may have been a seized compressor in the outdoor heat pump unit, as it has been turned off and is described in the listing as "decommissioned". But that is a 240 v circuit, so not likely to have overloaded the neutral, right?
I am wondering if a 120 v branch circuit breaker has failed to trip. Any ideas?
Are the neutral lugs on this Westinghouse panel rated for two wires?

John,

I'm sorry, but I am unable to find the scorched neutral. It is probably obvious and I am tired and not thinking straight.

I do see the improperly doubled neutrals. As far as I know, there is no time that a doubled neutral is acceptable.

To answer part of your question, scorched neutrals are most often caused by loose connections.

I don't see any damaged wire in these pictures either. If the concern is the white wire in the third picture, the coloration is typical of fabric covered wire.

John,

This is a good question for a certified, licensed electrician.

Is this a "Federal Pacific" panel? It looks like a few I have seen. These "Federal Pacific" panels were recalled for various bonding and overheating issues.

I also wonder if the double taped neutral has something to do with it. It does not appear that this panel was made for double tapping.

Regards,
David Selman
Selman Home Inspections
Home Inspection Professionals With A Free Limited Warranty

Originally Posted by David Selman

...These "Federal Pacific" panels were recalled for various bonding and overheating issues...

Recalled? When?

Closer inspection of the 4th picture at a BUNCH of magnification shows what appears to be discolored insulation on the 4th lug from the left bottom row. The copper under the double tapped terminal looks discolored as well. I'd still say loose terminal. This Westinghouse panel is old enough doubled neutrals may have been OK at the time - can't tell without the paperwork.

Originally Posted by Bill Kriegh

This Westinghouse panel is old enough doubled neutrals may have been OK at the time - can't tell without the paperwork.

Bill,

I disagree. To the best of my knowledge, doubled neutrals has never been acceptable. It was misunderstood by electrical contractors and inspectors alike due to poorly worded installation instructions.

Gunnar, I've got a picture of a label somewhere. It definitely says double neutrals are OK in that particular panel (the one the label was in).

If I can find it in my archives I'll post it for you.

Originally Posted by Bill Kriegh

I've got a picture of a label somewhere. It definitely says double neutrals are OK in that particular panel (the one the label was in).

If I can find it in my archives I'll post it for you.

Bill,

I would like to see that too.

Many years ago I held the position that two neutrals in one terminal was allowed because a manufacturer COULD (was allowed to) list their panel that way, however, years ago I changed that position as I have been told by everyone (except you in the above) that NO manufacturer EVER DID list a panel for two neutrals - thus 'it was never allowed".

If you find that photo, it would mean that I was actually correct with my previously held position - that *IF* a manufacturer listed their panel that way, it was allowed as the NEC did not disallow it at the time.

Always learning and always updating my thoughts and positions. Looking forward to that photo.

It appears to me that scorched neutral may have been caused by someone working in the panel and may have accidentally touched the neutral and hot lead to the neutral end and caused the scorching noted at the bottom of the main neutral wire. The lug does not appear to be scorched only the neutral wire tip. So to me that would indicate that the panel had likely been worked on. Unless there are other red flags to indicate otherwise I think that is likely the cause.

Double neutrals are acceptable at this location as long as they are not double lugged.

Although up to 3 branch circuit neutrals are allowed on one lug providing they are twisted and been crimped . Some local jurisdictions may not accept it but it is allowed and is common practice in today's building industry.

Originally Posted by Donald Lorette

...Although up to 3 branch circuit neutrals are allowed on one lug providing they are twisted and been crimped . Some local jurisdictions may not accept it but it is allowed and is common practice in today's building industry.

2006 IRC 3606.4 Grounded conductor terminations. Each grounded conductor shall terminate within the panelboard on an individual terminal that is not also used for another conductor, ...

From the last picture the 4 th from the left looks discoloured. When it is this close to the termination point the first thing I would check is the tightness of the connection. This wire is doubled up with another one and if the other wire is a larger size this will cause a problem and if it is loose this to will also cause a problem , mainly overheating which burns and discolours the wire.From the photograph it does not appear to be from overloading because the hot should also show signs of over heating but from the picture this is not eveident.If the breaker or fuse is sized to the wire ampere rating this should not happen under an overload or locked rotor condition as these should disconnect the circuit before any damage to the wiring happens.This is why sizing fuses or breakers to the wire capacity is so important.Eg. #14 wire always protected by a 15 A fuse or breaker maximum...........Joe

I stand corrected. It is the Equipment grounding conductors not the branch circuit grounding conductors that can have up to three per lug .

Manufacturer specifications can supersede building code. Read the manufacturer installation specs and you will be surprised what they recommend and they are UL approved.

Bill & Donald,

This is one of the labels that I have seen. The manufacturer gives permission to have multiple grounds, but not multiple neutrals. I have yet to see a label allow multiple neutrals. But, then again, I have not seen all panels that have been manufactured. So, as Jerry already said, please post it.

Originally Posted by Bill Kriegh

To answer part of your question, scorched neutrals are most often caused by loose connections.

I don't see any damaged wire in these pictures either. If the concern is the white wire in the third picture, the coloration is typical of fabric covered wire.

OK, it looked scorched or melted to me, with a drop of goop oozing off the end but maybe not. My clients want to upgrade to 200, so they'll be a getting a new service anyway.

As noted in my prior posting I stand corrected. As to multiple neutrals on the same lug is not allowed you are correct. Good to have people critiquing these postings.

I do not currently have any photo's of panel labels.

Originally Posted by John Kogel

OK, it looked scorched or melted to me, with a drop of goop oozing off the end but maybe not. My clients want to upgrade to 200, so they'll be a getting a new service anyway.

Anti-oxidant goop?

Originally Posted by Bill Kriegh

Closer inspection of the 4th picture at a BUNCH of magnification shows what appears to be discolored insulation on the 4th lug from the left bottom row. The copper under the double tapped terminal looks discolored as well. I'd still say loose terminal. This Westinghouse panel is old enough doubled neutrals may have been OK at the time - can't tell without the paperwork.

Posting another pic.

Originally Posted by Donald Lorette

I stand corrected. It is the Equipment grounding conductors not the branch circuit grounding conductors that can have up to three per lug.

Donald,

Actually that is not correct either, the branch circuit groundING conductor ARE equipment groundING conductors.

I suspect you meant "not the branch circuit groundED conductors".

There is a BIG difference in that ING and ED after the "ground" term.

GroundING conductor are the equipment grounds.

GroundED conductor is the neutral.

Couldnt the neutral be out-of phase? (providing it was discolored)

That neutral doesn't look so much scorched as it does old. It also seems to be of a larger size than the other service conductors and is probably aluminum not copper. Possibly recycled material.

Originally Posted by Steve Zabarylo

That neutral doesn't look so much scorched as it does old. It also seems to be of a larger size than the other service conductors and is probably aluminum not copper. Possibly recycled material.

Because of the cloth cover, I would think it is tinned copper. I have read that they tinned the copper before coating it with rubber. That was why I did not think that goop was anti-oxidant, but melted rubber. You can see a hint of copper in the pic.
But that is right, it was probably already old in 1964.