Melted Neutral SE. What's the cause?

Specific Inspection Topics Electrical Inspections
1

Saw a panel, the other day.

Everything looked fine. One exception.

The Neutral SE, where connected to the Service Equipment, displayed some green corrosion (copper conductor) but there was evidence of old melting of the insulation.

Any Ideas? I know there is a reason for just the neutral to display this.

There was no clear ground on this SE panel.

Thanks;

2

currosion = resistance. resistance = heat?

3

Loose connection.

4

Additional point

  1. There rest of the panel was neat and clean and no problems.

  2. The panel face screws were ALL pointed wood screws and 2 (or 4) were rusted at the ends.

I just know that I had seen an explaination on this board somewhere!

Reletated to grounding, somehow.

5

It appears from the melting on the insulation it once got hot from a loose connection. Or could be loose now. Have seen it several times. Could be other though…

6

If the “melting” is just around the lug, then I too would suspect a poor connection from corrosion and the subsequent arcing. If more of the conductor (at the drip loop etc) was in similar condition, then I’d guess a lightening strike on the utility’s grounded conductor or some other type of short or surge.

Whatever the cause, I’d say it’s now in a condition that warrants repair.

7

Lets not also forget guys that the neutral could also be undersized…without knowing the AMPS, the Grounded Conductros Size…and all the factors…yers it can be loose connection…or it could be undersized…with the advent of so many linear and non-linear issues and harmonics and so on in new homes…could just be a poor electrical design.

A good mind will not block out all the options to consider…:slight_smile:

8

Loose connection to cause that…

A missing GEC will not cause that.
I have found 20 and 30 year old homes with no GEC at all with no problems.

9

Dude…Said NOTHING about a loose GEC…Loose Neutral Connection…Please read the post…!

10

What kinda bothers me about the picture is the fact that the other wires don’t show any signs of heat damage… You know the conductors in very close proximity at the connection point. hmmm Any comments…:smiley:

On a different note:

Last night attended a open house at ITA… Had a little spiel about GFCI / AFCI… Had some input to give regarding bogus UL listed testers and the fact that a new release was made that all AFCI testers are NOT verifiable methods of properly testing a AFCI device… per UL Hmmm Sure-test and all… WOW

Also heard but can not confirm …hear that GFCI / AFCI could be a whole house issue (pushing to start in 2008… that will be the day $$$$$$

Feed back from the board sparkies…:smiley:

11

I believe all testing of GFCI’s and AFCI’s should take place at the Receptacle and Breaker itself as the only real approved method by the manufacturer. While a SureTest will trip most all GFCI situations…it relies on 2nd party perspective…the manufactures prefer it to be internal tested from the reset buttons.

As for the whole house deal…Thats going to be a tough one…might require it on all 15A and 20A branch circuits…but not the whole panel because it would have to be intergrated…otherwise explain when a 20A AFCI trips the entire panel…I can hear the whining now…and its only 2006…:slight_smile:

The day a whole panel becomes AFCI and GFCI protected will be the day the systems get SMART and all 42 breakers are intergrated, switchable between 120V and 240V and totally customizable…otherwise a main breaker will never be AFCI and GFCI protected in my opinion…something that needs to be controlled on a Branch Circuit level…

Now I am off to FIX a smoking Electrical Panel…:)…Love those after hours calls…:slight_smile:

12

I am not sure the world will be ready for an integrated panel anytime soon. There is too much invested in the molded case circuit breaker business

13

Pictures, pictures…we want to see pics tomorrow Paul.:slight_smile:

14

Paul, your not the only poster here, it was mentioned earlier ok :slight_smile:

15

lol…Hmmmmm I did not see anything about a GEC being loose causing it…Hell I know I am not the only poster here bruce…how boring would that be…thehehehe

16

No pictures guys…just a melting Cutler Hammer Breaker…Could have been nasty but we FLEW IN on our white horse and fixed it…But just goes to show…Federal Pacific and Zinsco are not the only BURNERS in the mix…thehehehe