200 amp main panel toasted

[Charley L. Bottger]

I observed a 200 amp panel yesterday that was installed in 04 I noticed severe burn marks on the outlet side of the 200 amp breaker and some smoke marks where the indivual breakers were connected. I took this as serious stuff. The owner of the home was present at the time of inspection and I knew him personally from my other life Due to the serious nature of this I pointed this out. He stated that his son-in-law whom is a licensed electrican installed the panel and that he would be right over and he was. He pulled all of the breakers and the left side buss bar was toast as was most of the breakers on that side. He stated that it appeared to be from a lighting strike. My thinking was loose connection as there was no damage to the other buss bar and no damage within the home. My expericense with lighting strikes is most usually you loose your television your computer your refig and most every thing in the home and I am talking from personal expericense. There were no surge protection divices in use any where.

I made no comment as to the lighting strike because I think the son-in-law was saving face with his father-in law and the repairs were being performed immediately.

Give me your thoughts on this and no I did not take pic's

[brian winkle]

Yes I have seen that scenario many times, usually a poor connection at one of the main lugs, or, like you noticed, a loose connection where the main breaker connects to the buses. I have seen NEW panels out of the box with loose connections there. The one side will heat up and ruin that whole bus, breakers and all. The heat will damage the other breakers also since they are staggerd. I have seen them to the point of a complete meltdown. All the ones I have seen had AL service conductors which I presumed were not properly torqued or treated with AntiOx. Also, most of the ones I have seen were Murrays/Siemens.

The only time I saw a service that had been damaged by lightning it was so bad all the breakers were melted into a pile of black unrecognizeable plastic and the wires at the drop were burnt and melted.

[David A. Andersen]

Remember, a loose connection has a cascading effect.
Loose = high resistance = heat.
Heat increases resistance = more heat.
More heat = .............................