sharing neutral and voltage drop of differnet size wires

[Jodonnell]

Not sure if I can do this. I have three receptacles circuits that I would like to share the neutral on. I have to increase the size of the wire for voltage drop.

Circuit A #6 wire .9kw
Circuit B #8 wire .72kw
Circuit C #10 wire .30kw

Can I have the hot wires #6, #8, #10 and then the neutral wire #6 or do I have to increase all of the hot wires to a #6 in order to share the neutral. I have never seen this completed and not sure what the correct answer is. I have not been able to find anything on my searches or in the NEC.

Thanks

 

[iwire]

Mix sizes as much as you want.

 

[Volta]

Depending on your voltage drop, the grounded conductor can be as small as your #10 hot, or even a 12 if 20 amp circuits. For lowest VD, of course, larger will help, but not needed.

Don't forget 250.122(B) which will require you to upsize the grounding conductor in relation to the ungrounded wire(s).

If you only increase the size of the grounded conductor, however, you can lower the VD and won't need to increase the EGC. Might be the cheapest alternative.

 

[cchongj]

Not sure if I can do this. I have three receptacles circuits that I would like to share the neutral on. I have to increase the size of the wire for voltage drop.

Circuit A #6 wire .9kw
Circuit B #8 wire .72kw
Circuit C #10 wire .30kw

Can I have the hot wires #6, #8, #10 and then the neutral wire #6 or do I have to increase all of the hot wires to a #6 in order to share the neutral. I have never seen this completed and not sure what the correct answer is. I have not been able to find anything on my searches or in the NEC.

Thanks

Article 250.122(b) states that ungrounded conductors are increaseed in size, equipment grounding conductors shall increased in size proportionately according to the circular mil area of the ungrounded conductors.