600v rated cable support in concrete pit

zeilzabob

Member
I have a 4000 amp 480v service and below is a concrete pit approx 10' wide 5' deep and 25' long. Engineered steel structure for the service to sit upon on top. The idea is to bring feeder conduits into the pit and then free air from where it enters to the associated branch breaker. In some cases this will span 20'. I cannot find in the NEC the support requirements for the cabling within the pit. I see in 328 its 6' but I do not find anything for 600v rated cables. Any help is appreciated.
 

zeilzabob

Member
According to a local electrical engineer it falls under 328.30 new for 2017. Since the MV grounding conductor is run with MV cable and approved to be routed with the 6' support rule these would fall under the same rule.
 

zeilzabob

Member
480v install. But the grounding conductor that would be pulled with the MV cable is 600v rated and required to accompany. That is where he is getting the interpretation.
 

zeilzabob

Member
The facility was already inspected and signed off on. It was just recently brought up as a question.
 
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zeilzabob

Member
The inspector reviewed the pit, and the switchgear sitting above. I am unsure if he had seen how the cabling was supported. There was conversation on the pit and gear and there was no issue with it at that time.
 
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