Dear Experts, I have some trouble with NEC grounding code provisions. I've been doing this for a long time from Electrical Plans of different Design Companies for industrial plants & comm'l complexes even in power staion switchyards & substations but only now that I begin to queston. Here it is :
I am running an insulated Equipment Grounding Conductor from MCC grounding busbar to motorised equipments (pumps compressors HVAC equip) along with the phase wires terminating on motor ground lug or terminal box itself.
Also I am running a "bare cooper wire from motor chasis to a ground bus" on the room wall then two wire loops around other ground bus on other rooms, each ground bus has a wire going to the grounding electrode (ring & rods or grids) outside.
- What do I call this "bare cooper wire from motor chasis to a ground bus" ,seemingly second type of ground wire?
- Where in the NEC states that it is needed, required or safe to install this? Is it always required?
- What is the equivalent of this on the IEC standards? I ve read from an ABB manual that there is only one PE ( the equivalent of EGC) for all T-systems.
- I suspect that this wire can defeat the purpose of GFrelays that fault current running on the EGC will too weak to de activate the breakers since fault current will be divided via "second ground wire". if relays are not set properly. Is it correct.
If its no in the NEC then it is not violation if it is removed? Really need the views from the Roughnecks out there before I go to Mike Holt or McPartland. Thanks Guys