ken44
Senior Member
- Location
- Austin, TX
I am working on a commercial remodel job which requires several isolated ground panels. The job requires working with a State Agency and they have their own electrical supervisor/inspector who I am at odds with on the following code issue. The diagram on the blueprints shows a 3 wire system with the conduit(EMT) being the equipment ground. The supervisor/inspector says the system must have a fourth wire because the EMT is not sufficient for an isolated ground receptacle, he cites article 250-30 which makes mention of seperately derived systems, I dont see where he is coming from, we are using EMT with steel, set screw connectors and steel, set screw couplings, I am of the understanding from my past mentors and the NEC that this is sufficient for an equipment ground. For those of you who are knowledgeable in these isolated ground systems, I would appreciate your insight and sharing experience which lends itself to this subject.