Explanation needed

[HotConductor]

I had a convenience store with an issue every few months. They would get dimming in the store and the main breakers(200a) would trip on occasion. I narrowed it down to birds living in the service head. From coming in and out they had worn the insulation off the neutral conductor and it was bare. After cutting the neutral I realized that it was waterlogged. I can understand the dimming but not the tripping?

Any good explanation?

 

[charlietuna]

I don't think you have found "THE" problem, maybe "A" problem ?

 

[Buck Parrish]

Bare neutral is not going to
be it.
It's either the main is going bad. Or a hot phase may be rubbibg a tree and bare. Or some over heating in the panel.
​

First ask the poco to look at their connections. Sometimes you have to ask twice.

 

[S'mise]

Could be mains but I'd be looking at the cooler loads or some other load. If service drop had a short, it would melt but probably not trip the cb down stream.

 

[wirenut1980]

I agree to start looking on the load side of the main breaker. Could be a bad branch circuit breaker or could be a branch circuit wiring or load intermittently faulting.

 

[AV ELECTRIC]

I have seen bare conductors ran in older houses for the neutral . I think you need to ask more questions to the customer do they notice a buzzing sound when the lights dim and the breaker trips if so it sounds like a major short but in that situation you would think you would not be able to reset the breaker. the other is overload is something with a high draw coming on at this time and like others said the main may be failing pull it out and inspect it .

 

[HotConductor]

Thanks guys. I pulled new SE conductors in about two months ago and so far so good. I didn't megger the conductors but maybe there was tracking inside the service drop.