Minimum Size Grounded Conductor for a Branch Circuit

[Dennis Alwon]

Smart I think you make a very good point, however, I would be curious if the intent was to mean the grounded conductor to be smaller. Good find.

Personally I think there should be a statement in 210.19 that states the grounded conductor for a branch circuit shall never be smaller than the egc. That would be consistent with the rest of the code and, I believe, that is the intent.

 

[Smart $]

Smart I think you make a very good point, however, I would be curious if the intent was to mean the grounded conductor to be smaller. Good find.

Personally I think there should be a statement in 210.19 that states the grounded conductor for a branch circuit shall never be smaller than the egc. That would be consistent with the rest of the code and, I believe, that is the intent.

I agree, and doubt the intent was to permit a circuit conductor to be smaller than its EGC. I believe the possibility has simply been overlooked due to other requirements keeping the probability of such extremely low.

 

[kbsparky]

Geez Charlie, so why do we have a #12 EGC in 12/2 NM cable and not #14? ...

They do in Canada. It's called "NM-D"

 

[kbsparky]

I've connected several hot tubs with a reduced neutral. They required a 50 Amp circuit, but the neutral was only for the control wiring and a light. All the main loads operated on 240 Volts.

So, we installed #6 hots, a #10 neutral, and a #10 ground.

FWIW, the internal neutral wire was only a #14 coming from the terminal block.

 

[Dennis Alwon]

I've connected several hot tubs with a reduced neutral. They required a 50 Amp circuit, but the neutral was only for the control wiring and a light. All the main loads operated on 240 Volts.

So, we installed #6 hots, a #10 neutral, and a #10 ground.

FWIW, the internal neutral wire was only a #14 coming from the terminal block.

Yeah but what goes on inside the tub is not our issues. I have seen reduced neutrals also but they have never been smaller then the EGC.

 

[Dennis Alwon]

but the neutral was only for the control wiring and a light. All the main loads operated on 240 Volts.

Exactly, the load for the neutral could have been a #12 but they probably realized it was a bad idea to have the neutral smaller than the egc.