Outside Panels Copper vs Non-Copper Buss

[Ravenvalor]

Hello,

So about 3 - years ago my local Siemens supplier stopped selling meterbase panel combos with copper busses. This has led to more expensive jobs where a meterbase panel combo would have saved on labor and material. Is there still a corrosion issue of a non-copper buss in an outside panel?

Thanks again for the guidance.

 

[Coppersmith]

I buy non-copper bus outside panels all the time and never had any complaints.

 

[robertd]

Hello,

So about 3 - years ago my local Siemens supplier stopped selling meterbase panel combos with copper busses. This has led to more expensive jobs where a meterbase panel combo would have saved on labor and material. Is there still a corrosion issue of a non-copper buss in an outside panel?

Thanks again for the guidance.

I thought the buss bars were all plated with tin, both copper and aluminum.

 

[Coppersmith]

I thought the buss bars were all plated with tin, both copper and aluminum.

They are either copper or aluminum. The copper ones are copper colored so no plating there. I don't believe the aluminum ones are plated either but it's hard to tell at a glance. (My answer is for resi panels. I don't know how industrial panels are done.)

 

[petersonra]

They are either copper or aluminum. The copper ones are copper colored so no plating there. I don't believe the aluminum ones are plated either but it's hard to tell at a glance. (My answer is for resi panels. I don't know how industrial panels are done.)

I think all aluminum bus is tin plated. otherwise it gets a coating of aluminum oxide over time.

 

[jim dungar]

I thought the buss bars were all plated with tin, both copper and aluminum.

Depends on the manufacturer. For example Square D QO yes, Cutler Hammer CH no

 

[curt swartz]

From the Square D and Eaton load center specs.

Square D HOM
Tin & copper plated aluminum bus bars

Square D QO
Tin-plated copper bus bars

Eaton BR
Tin-plated aluminum

Eaton CH
One Piece Silver Flashed Copper Buss

Siemens does not plate their copper bus loadcenters but does tin plate the aluminum bus loadcenters.

I have not worked with GE/ABB in a long time but as I remember all of their loadcenters were tin plated copper.

 

[GoldDigger]

I think all aluminum bus is tin plated. otherwise it gets a coating of aluminum oxide over time.

Which means that to be acceptable all metal to metal connections to an unplated Al bus must be gas tight. The act of making the connection mechanically breaks the oxide layer(s) and that metal to metal contact does not allow oxygen to reach the contact surface.
The alternative is to use an anti-oxidant and/or conductive coating.

Copper oxide is also non-conductive, but has a rediculously low breakdown voltage. Copper oxide rectifiers, before semiconductor diodes, needed a lot of layers.

 

[Ravenvalor]

Copper Buss panels have a longer warranty, so I am told.

 

[kwired]

Copper Buss panels have a longer warranty, so I am told.

So instead of being warrantied until as soon as you walk out the door it is good until you leave the driveway?

 

[norcal]

The AL bussed Gould/ITE 200A meter main on my rental installed in 1980 is still in good shape, even remember the price paid for it. ($100) Used it as a example since the entire history is known, and was shifting things around during a remodel in 2018 & to remove any non ITE or Siemens breakers.

 

[Ravenvalor]

Which means that to be acceptable all metal to metal connections to an unplated Al bus must be gas tight. The act of making the connection mechanically breaks the oxide layer(s) and that metal to metal contact does not allow oxygen to reach the contact surface.
The alternative is to use an anti-oxidant and/or conductive coating.

Copper oxide is also non-conductive, but has a rediculously low breakdown voltage. Copper oxide rectifiers, before semiconductor diodes, needed a lot of layers.

With this in mind it seems like a Siemens AL buss may work well. One idea would be to put a breaker on each buss regardless of whether a circuit is connected to it or not. It might prevent oxidation at the point of contact.

Probably want to try to avoid using tandems and quads to keep the heat down.

 

[petersonra]

With this in mind it seems like a Siemens AL buss may work well. One idea would be to put a breaker on each buss regardless of whether a circuit is connected to it or not. It might prevent oxidation at the point of contact.

Probably want to try to avoid using tandems and quads to keep the heat down.

I seem to recall most panelboards used to come with a thin coating of grease on the bus bar. Do they not do this anymore?

 

[jim dungar]

I seem to recall most panelboards used to come with a thin coating of grease on the bus bar. Do they not do this anymore?

The Square D QO and I-line breakers have the 'grease' on the breaker jaws. You are not supposed to relocate the breakers without checking the Plug-on Joint Compound, which is sold in small squeeze tubes.

 

[kwired]

With this in mind it seems like a Siemens AL buss may work well. One idea would be to put a breaker on each buss regardless of whether a circuit is connected to it or not. It might prevent oxidation at the point of contact.

Probably want to try to avoid using tandems and quads to keep the heat down.

If you can plug on a 2-20 amp tandem on the same spot you can plug on a 100 amp breaker - I doubt this is really much of a problem.