Aluminum Busway Coupling with Copper Panel

Sajid khan

Senior Member
Location
Pakistan
We have several aluminum busways feeding different loads through out the hospital building.
The busways shall be connected to different low voltage panels via Busway Flanges.

Our panels have tin plated Copper busbars and our busways are aluminum only without tin plating. Busway Flanges are also without tin plating.

Question is, Is it allowed to connect non-tin plated aluminium busway Flange with a tin plated copper Busbars inside the low voltage panel. I am worried because of the galvanic action of dis-similar metals?


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Sajid khan

Senior Member
Location
Pakistan
I have seen requirement in NEC Code for bimetallic lugs used in aluminium cable when connecting it to copper busbar in LV Panel.

The requirement regarding busway is not mentioned in NEC


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steve66

Senior Member
Location
Illinois
Occupation
Engineer
The manufacturer would know for sure. Why not call them?

That said, I wouldn't think it would be a problem, and I personally wouldn't worry too much unless there is visible signs of a problem.

Aren't tin plated bus bars made to connect circuit breakers with aluminum stabs or bolt on connections?
 

Sajid khan

Senior Member
Location
Pakistan
The manufacturer would know for sure. Why not call them?

That said, I wouldn't think it would be a problem, and I personally wouldn't worry too much unless there is visible signs of a problem.

Aren't tin plated bus bars made to connect circuit breakers with aluminum stabs or bolt on connections?
Manufacturer is not recommending for a bimetaic connection . According to manufacturer they will terminate aluminum (Not tin plated) with Copper Bar(tin plated) of Low voltage panel. But I doubt there could be a problem due to galvanic action.


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jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Retired Electrical Engineer - Power Systems
One of the common reasons copper bus is tin plated is to prevent issues with dissimilar metals, like aluminum.

Ideally the aluminum would also be plated, but there are lots of panelboards installed this way.


There are no unique requirements just because it is busway.
 
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