Tinned Copper Earth Bars

[BritEng]

Hi,

Can someone please assist. Do we need to tin copper earth bars when bolting tinned copper cable lugs to it. I am working on a project where we have coflicting opinions. Some bars are in a substation and some on site for plant earthing. Project is in the UK.

Best regards

 

[waross]

My understanding is that tinning is to protect the bussbars from the formation of copper oxide. I have used many plain brass connectors with tinned bus bars. It has never been a problem. I also run across distribution transformers with tinned lugs. No problem bolting plain brass connectors.
respectfully.

 

[RajT]

There is no technical reason for not doing what you are doing.Lugs in are generally tinned anyway and earth bars are usually untinned.
As long as the connections are dry, copper oxide should not form.

 

[waross]

Hello RajT
I agree with you. I was refering to the oxide that often forms on the surface of the bars over time. Once a connection is bolted up, with clean surfaces, oxidation does not usually form in the connection. A corrosion inhibiter applied to the surfaces prior to bolting up is a good idea.
respectfully