Grounding

[canova]

I have a 4000 amp 480/277 volt three phase four wire bussed weather head with main disconect for one building 300 amp and three more mains will be added. Will the main ground be sized for 4000 amps or will each main have a seperate ground

 

[charlie]

Re: Grounding

I am having a bit of trouble understanding what you have. Assuming a single 4,000 ampere switchgear with multiple disconnecting means, you will size the grounding electrode conductor for a 4,000 ampere service. Assuming up to six disconnecting means in separate enclosures, you will need a separate grounding electrode conductor for each.

In the second scenario, you are also permitted to run a single grounding electrode conductor and tap off of it to each individual service disconnecting means.