robert_duncan
Member
- Location
- dallas, texas, usa
What is the difference between a protective and operating ground as refer to in the 2011 NEC 810.51(I) ?
Hello Robert welcome to the forum.:thumbsup:What is the difference between a protective and operating ground as refer to in the 2011 NEC 810.51(I) ?
Best guess...What is the difference between a protective and operating ground as refer to in the 2011 NEC 810.51(I) ?
Hello Robert welcome to the forum.:thumbsup:
Do you mean 810.21 (I)..?
I believe you are correct. I had it backwards.In the 2008 it is mentioned in 810.58 B and C.
I just did a class on radio bonding and grounding. I take it to mean that the protective conductors are the grounding conductors that connect the antenna ground to the grounding electrode system and the operating conductors are the conductors that connect the equipment to the grounding electrode system.
Neither are defined by the NEC. If my interpretation is different (after being an amateur radio operator for 20 years come July) and can be proven incorrect I would like to know about that.
Hello Robert welcome to the forum.:thumbsup:
Do you mean 810.21 (I)..?
You could try to get a formal interpretation, but there are specific rules and your question must be formated in a manner so it can be answered "yes" or "no". A call to the NFPA staff would get you an informal answer, or you could submit "public inputs" (proposals) for the 2017 code and see what the panel statements say when the "first draft" (ROP) comes out.Would there possibly be a way to get the official definitions of 'operating ground' and 'protective ground' from the NFPA?
We are pretty much left to guess what they mean, and I don't think we should have to do that.
You could try to get a formal interpretation, but there are specific rules and your question must be formated in a manner so it can be answered "yes" or "no". A call to the NFPA staff would get you an informal answer, or you could submit "public inputs" (proposals) for the 2017 code and see what the panel statements say when the "first draft" (ROP) comes out.
You could also look the the ROPs and ROCs from when the language became part of the code and see what the substantiations and panel comments said.
You could try to get a formal interpretation, but there are specific rules and your question must be formated in a manner so it can be answered "yes" or "no". A call to the NFPA staff would get you an informal answer, or you could submit "public inputs" (proposals) for the 2017 code and see what the panel statements say when the "first draft" (ROP) comes out.
You could also look the the ROPs and ROCs from when the language became part of the code and see what the substantiations and panel comments said.
Technically there is no difference, both terms refer to the bonding conductor (or bonding grounding electrode conductor) used to bond between grounding electrodes (rod to rod or rod to concrete encased electrode (see 250.52). The term is based on language used in European standards where protective ground or protective bonding is used where the grounding electrode system is specified in US standards. An effort was initiated in NFPA 79 to use such IEC terms wherever a grounding term was used. However, it just created confusion and such terms were put into an Annex for the 2015 edition of NFPA 79 along with explanations for their use in the IEC standards. See the information figure 800(a) and 800(b) for an example of such bonding conductors. Protective grounding (earthing) is another IEC term for the grounding electrode system in US standards. The reference in 800.58 refers in one mode the connection to earth for operating with regard to the lead-in conductors and the other simply for protection similar to the grounding electrode system in 250.50.
Mark Cloutier
Sr. Electrical Engineer