Rusty bus bars

[Jim Baird]

Two panels in a little utility room off a carport, not heated or cooled.  Both panels had rusty bus bars and terminal screws both sides.  30 yrs old.  

I have never seen the likes.  Has anybody here?

 

[Jim Katen]

Looks like some kind of airborne contaminant. I see this kind of early stage corrosion from pool chlorine. 

[Marc]

Yeah, this morning on the neutral bus of an old FPE panel that had the neutral floating like a bird.  Couldn't loosen a single one of them dang screws or lugs. Outdoor location though. A utility room off of a carport will have a wider range of moisture levels than outside. That's because of rapid temperature changes and little means for moisture to escape. That's not an unusual finding this close to the Louisiana Gulf Shore.

Edited August 22, 2020 by Marc

[Trent Tarter]

I have seen this many times over the years. 

[plummen]

High humidity?

[Jim Katen]

18 hours ago, plummen said:

High humidity?

We have tons of outdoor panels here in Oregon where there's plenty of high humidity for about half the year. But the only time I see corrosion like this is if the house is near the coast or if there's some kind of contaminant in the air.