jar546
Forum Coordinator
The 2011 NEC has a change in article 250.121 that reads:
Many want the entire section removed from the NEC but the CMP has held steady on this one with the following comments:An equipment grounding conductor shall not be used as a grounding electrode conductor.
Do any of ya'll ("yous guys" if you're from NJ/NY) have an issue with this section or a problem with ECs complaining about it?The panel re-affirms the position that the GEC and EGC’s have different functions and shall not be used as both. The substantiation for the proposal contains some of the reasons this proposal is not acceptable. This includes the fact that the two conductors are installed for different purposes, are sized differently and have different installation requirements. Here are a few illustrations of why the rule needs to remain in the NEC. (1) An equipment grounding conductor is required to be installed with the circuit conductors to the transformer enclosure. 250.30(A)(4) requires the grounding electrode to be “as near as practicable to, and preferably in the same area as the grounding electrode conductor connection”. These locations could and often are widely separated.
(2) A feeder is installed from a source in a building to a transformer that is located outdoors. 250.30© requires the grounding electrode connection to be at the transformer that is the source of a separately derived system. A combination grounding electrode conductor/equipment grounding conductor run to the source location would not be acceptable.
(3) A supply to a transformer-type separately derived system is installed from a sub-panel (feeder panelboard). Where would a combination grounding electrode conductor/equipment grounding conductor be connected? To the neutral terminal bar? A clear violation of 250.24(A)(5). To the equipment grounding terminal bar? The equipment grounding conductor supplying the panelboard may not be large enough.