I had some lights flickering, so I went to the breaker box, and I could hear quiet buzzing/crackling. I pulled the breaker (type EQ-P), and the buss bar was badly corroded, as was the contacts on the breaker. A few years ago I had something similar happen to another circuit, and this time the buss bar was sufficiently damaged. I left that slot open, and put in a couple of half-height breakers to replace it. I am wondering if these breaker types are the culprit, or what else is going on. At a minimun, I need to pull the breakers and clean up that buss bar (mains off, I know...). Is this replacable? SHould I replace the bar? I have not detected any overload conditions, and the box is not exposed to extremes in temp or humidity. Water could not get to the box either. It could get a bit damp in the summer (it is in the basement), but not so bad..

Any suggestions would be greatly appreciated.

Brett

 

You wanna bet water can get into the panel! The service cable can act like a conduit flowing water from the weatherhead, through the meter and into the panel. Everything can look peachy on the outside. Open the panel or meter and you'll get a surprise.

You need to replace your service panel at the least and most likely you need a whole new service. If your buss is this bad already and you say this is not the first time this has happened I can imagine what the main breaker or meter looks like inside. I would not replace and parts either. The whole thing needs to go. The buss is nothing to take chances on.

 

No, I said that there was no water problem. I opened the box, and it is completely clean, dry, and uncorroded. Only the bus bars at the points of contact for the 2 failed breakers show corrosion. The corrosion is more of a pitting rather than rust. It is perfectly clean in the box, with the exception of a super light layer of dust, which does not have any tracks that you would expect if water were getting in there.

Brett

 

You can shut off the power to the panel (shut off the main), measure to make sure you have no power, then clean the bus bar contacts with a wire brush (with an insulating handle and gloves). You can either replace or try to clean the breaker contacts also, then use some electrical grease to coat both the bus bar and the breaker contact. Not too much, just enough. Make sure you stay away from where the main feed comes in the box.. that is still live.

 

Oh, you probably live in a salty and moist enviroment.. corrosion is more frequent in those enviroments.

 

By my thoughts, I do not live in a wet salty environment. I live in Chicagoland. As I said before, the problem does not appear to have anything to do with rust. The entire contents of the box remain clean and rust free. It is only the 2 places on the buss bar where the breakers were attached that had the pitting. I am sure this is due to arcing. I just am not sure what is causing the arcing or corrosion. I may try to get a replacement buss bar, figuring that there may be some plating on the bar that was damaged. Plus one of the spots with corrosion is pretty badly eroded away. If not I will clean it up really good as you suggested, and replace the breakers that have corrosion (might as well-they are cheap). I also like the idea of the electrical grease. I assume you mean dielectric grease. Instead of the dielectric grease, I am wondering if conductive grease would enhance the contact between the breaker and the buss bar. Any thoughts on this?

Brett

 

All new breakers have a bit of dielectric grease on the contact terminals (at least SquareD breakers do).
It may be that the contact pressure between the breaker and the bar weakened over time. A new breaker should solve that problem . I don't think you need a new bus bar, which incidensly is not easy to replace in most panels.You'll usually have to get a whole plate with the two busbards, in which case it will be less expensive to just replace the panel.

 

I replaced the breaker adjacent to the problem slot with a dual breaker, and moved the load from the problem slot to the second output of the dual breaker. I pretty much considered this a fix to the immediate problem of the damage to the buss bar.

I would feel much better if I could be certain of the cause of this. I do believe the possibliity of age could have weakened the contact pressure at the buss bar.

Thanks a bunch to all who offered their advice.

Brett