Bonding grounding electrodes conductors
Bonding grounding electrodes conductors
(OP)
Is it necessary to bond the grounding electrode conductor when it enters metallic enclosures at the sevice equipment and separately derived systems. My design did not call for a connector at the point of entrance to the metallic enclosure and the Electrical Inspector is requiring that I use the appropriate listed fitting.






RE: Bonding grounding electrodes conductors
Remember, if you start a war with the inspector, he has bigger "Guns". You may win some battles but you will definitely lose the war. Your best course of action is to ask the inspector politely what he requires, listen quietly, and proceed with his wishes.
RE: Bonding grounding electrodes conductors
RE: Bonding grounding electrodes conductors
My copy of the NEC is out of date, but it covers induction heating, which is a direct result of the "Choke" effect the inspector is concerned about. It gives a specific exemption for grounding conductors.
I respectfully disagree with the inspectors interpretation of the code. However, after discussion with him, I would comply with his wishes.
Now if this was 50 completed housing units, and I was looking at a large labour expense to correct it, I may consider a challenge to the ruling.
Further more, the main result of the choke effect is to heat the metal enclosure by the action of circulating currents. It will not limit the current to the extent that over current devices fail to operate.
I was aware of some tests conducted about 30 years ago by an Electrical Contractors association. They ran several hundred amps through a test conductor. They then passed the test conductor through a 10' length of 1/2" steel conduit. They found that the conduit choked the current of to about 100 amps. They then connected to conductor to the conduit at each end and found that about 100 amps flowed through the conductor and the rest flowed through the conduit.
I would suspect that the choke effect caused by a sheet metal enclosure would be related to the ratio of the thickness of the panel to the length (10') of the steel conduit.
How big is this installation? Sometimes size makes a difference. Is there something out of the ordinary here?
respectfully
RE: Bonding grounding electrodes conductors
RE: Bonding grounding electrodes conductors
NEC index under
Conductors; Parallel
Induced Currents in Metal Enclosures or Metal Raceway.
In an older edition, rule 300-20 (a), Exception number 1.
What type of connector is he requireing?
Is this grounding requirement applied anywhere else in the country?
respectfully.
RE: Bonding grounding electrodes conductors
Thanks for the imput.
RE: Bonding grounding electrodes conductors
respectfully