black buss bars

[mickeyrench]

We have a situation with a 800 amp 480v bolt on breaker . The buss bars the breaker is bolted to is black and flaking. It appears the bars are shedding. I followed the bars and instead of being copper they are totally black and i never seen any flaking of bars . Is this a sign of heat or lose connections? Ireally don't think there is any over load. I have taken amp readings and never seen a overload.

 

[wireguru]

sounds like a precurser to BOOM!

Is the black carbon deposits from a previous BOOM? Or is it some sort of paint or coating on the bars? Or is the actual metal discolored and turned black? Has it been underwater?

 

[stormywyo]

An acidic environment will turn copper black--

 

[480sparky]

Could the bus bars be copper-clad aluminum?

 

[charlietuna]

I have seen this before and is normal--the breaker's bus fingers are what your talking about and many manufacturers build these without any anozation coatings. But again it could be heat related without knowing it's cause. A good cause for infrared scanning....under load !!!

 

[charlie k.]

Is this by chance in a pumping station or waste water plant. If so it is from Hydrogen Sulfide.

Charlie

 

[zog]

We have a situation with a 800 amp 480v bolt on breaker . The buss bars the breaker is bolted to is black and flaking. It appears the bars are shedding. I followed the bars and instead of being copper they are totally black and i never seen any flaking of bars . Is this a sign of heat or lose connections? Ireally don't think there is any over load. I have taken amp readings and never seen a overload.

Any chlorine in the atmosphere? Sounds like a classic case of silver whiskers.

 

[jmargolis79]

Could the black flaking be tape. i have seen many buss bars that were wraped in electrcal tape.