NEC 2014 230.82 and 240.21

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DW98

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we have a #6 tap to a legally required standby power system disconnect from a fire pump section in a 2500A switchboard. My understanding is the wiring to the disconnect does not need to be sized to a percentage of the 2500A service conductors. This disconnect wiring is by definition not a tap but service wiring. This wiring was failed by an inspector who cited that it must be not less 1/10 the size of the service feeders. I think feeder taps are being confused with service wiring. Is my understanding correct, or am i missing something.

Thanks as always for reading and replying.
 
Your inspector is wrong. "Service feeders" isn't a NEC term either, you either have service conductors or feeder conductors and different rules apply to each.

Service conductors have no overcurrent protection on the supply end, and is part of reason why they have limitations on entry into a building.

A feeder tap does have overcurrent protection ahead of it, but length of tap is limited according to the conditions. Outside feeder taps can be unlimited length and no minimum ampacity as relates to the feeder OCPD, but have similar requirements as service conductors when they do enter a building.
 
Reply to Reply NEC 2014 230.82 and 240.21

Reply to Reply NEC 2014 230.82 and 240.21

The inspector and I discussed this topic. He was told by the e.c it was a feeder so he agreed that the conductors weren't taps. We then discussed the purpose of the connection ahead of the main, to serve exhaust fans (not for a high rise) which is allowed by NEC 701. He was confused why there wasn't a generator, but I told him a connection ahead of the main was allowed as a legally required source.
 
DW98 said:
The inspector and I discussed this topic. He was told by the e.c it was a feeder so he agreed that the conductors weren't taps. We then discussed the purpose of the connection ahead of the main, to serve exhaust fans (not for a high rise) which is allowed by NEC 701. He was confused why there wasn't a generator, but I told him a connection ahead of the main was allowed as a legally required source.
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Now I am confused, how is it a standby system when it doesn't involve an alternate source? What powers it when utility power is lost - that is a primary reason for standby systems whether legally required or not. As described it isn't a feeder or a feeder tap, it is service conductors and it shouldn't matter what EC says but rather what is ahead of it - no service disconnect on supply side means it is service conductors. Whether or not you can tie into existing service conductors as was done may or may not be code compliant, but they are still service conductors.
 
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