Bonding for under 250 volts

[dnunez]

250.97 states "For circuits of over 250 volts to ground, the electrical continuity of metal raceways and cables with metal sheaths that contain any conductor other than service conductors shall be ensured by one or more of the methods specified for services in 250.92(B), except for (1)." exception "Where oversized,concentric, or eccentric knockouts are NOT encountered, or where a box or enclosure with concentric or eccentric knockouts is listed for the purpose, the following methods shall be permitted."
My question: I have a 120/208V 100A 1Ph sub panel (concentric Knockouts)which is fed with a 3/1 cu Feeder MC I am using a Regal 6244 insulated throat MC connector. The fitting is sized to fit into a standard 1 1/4" KO and is threaded an shouldered. I feel I neither need a Plastic bushing or a grounding bushing. I would love your input. Thanks

 

[peter d]

Re: Bonding for under 250 volts

It's 120/208, so why would the section you posted apply?

The plastic bushing requirement is for raceways, not cables.

 

[infinity]

Re: Bonding for under 250 volts

First of all, the MC cable has it's own EGC and the outer jacket could not be used as an EGC since it is not listed as such.

Secondly, as mentioned, the section you quoted is for over 250 volts so that wouldn't apply here either.

 

[tom baker]

Re: Bonding for under 250 volts

There is a type of MC cable that the outer sheath is listed as an EGC. The spiral interlock is the most common type and its outer jacket is not listed as an EGC.