Need help!!?

[garnerm]

I designed a 208V panel to be feeded from a dry type transformer which is feeded from a 480V panel in the same elec. room. I sized the ground for the transformer to the panel on the secondary side via the equipment grounding table 250.122 in the NEC. My city electrical inspector said that the ground needs to be sized via the service entrance table 250.66. I think this is BS. has anybody ever run into this issues and if so how did you deal with it? Also, if you think he is right please explian why, and if not please help me figure out some key points in the code where I can build a case. Thanks for your help.

PS, I know this shouldn't be a service entrance ground because we are not changing buildings, this is in the same building, even the same room.

 

[david luchini]

The inspector is correct. That conductor would be, I think, either the system bonding jumper or equipment bonding jumper of the Separately Derived System (depending on where the grounding electrode conductor is connected.)

Either of those would need to be sized per 250.66. See 250.30(1) and (2).

 

[raider1]

I agree with the inspector, (And David )

The equipment bonding jumper between the the transformer and the panelboard would be sized based on Table 250.66. (See 250.30)

Chris

 

[garnerm]

Thanks for your help

Thanks for your help

Thanks for answering my question, after reading the code and handbook, I also agree with you guys and my inspector. We will be making the changes. Thanks again for the quick response.