paralleling nuetrals

[jazer]

Where in the code can I reference the concept of not using 3-#10's as a substitute for a single #8. This would be the nuetral wire of a three phase/four wire circuit. I think it is shady and I cannot find it to prove the point.
Thanks

 

[charlie b]

310.4 - NEC 2008 and earlier.
310.10(H) - NEC 2011.

 

[jazer]

I thank you, sir.

 

[dana1028]

Charlie -

Even though the OP titled his topic are 'paralleling neutrals' and you pointed him towards parallel rules, it seems he is really asking about multiwire circuits...i.e. he mentioned using a #8 in lieu of (3) 10's on a 3-phase, 4-wire circuit.

If that is the case - look at Art. 100 for the definition of what a multiwire branch circuit is [Branch circuit, multiwire], and 210.4 about rules for Multiwire Branch Circuits.

 

[Barndog]

Charlie -

Even though the OP titled his topic are 'paralleling neutrals' and you pointed him towards parallel rules, it seems he is really asking about multiwire circuits...i.e. he mentioned using a #8 in lieu of (3) 10's on a 3-phase, 4-wire circuit.

If that is the case - look at Art. 100 for the definition of what a multiwire branch circuit is [Branch circuit, multiwire], and 210.4 about rules for Multiwire Branch Circuits.

I agree with Charlie on this. I believe he is asking if 3 # 10's can be used instead of 1 # 8 for a neutral on a three phase panel. I also thought you cannot parallel anything smaller than 1/0 anyways.

 

[charlie b]

. . . i.e., he mentioned using a #8 in lieu of (3) 10's on a 3-phase, 4-wire circuit.

If the issue were turning a single circuit (of the MWBC variety) into three separate circuits (of the single phase variety), then we would be talking about substituting (3) #10's for a single #10. I can't see having #10 phase conductors and a #8 neutral as part of a MWBC.

 

[infinity]

You cannot use 3-#10 conductors to replace 1-#8 conductor in a 4 wire circuit.

 

[jazer]

You cannot use 3-#10 conductors to replace 1-#8 conductor in a 4 wire circuit.

This is the case. I am not trying to create a multiwire branch circuit. It is for a trash compactor. Specs call for a 40 amp service, 208v, three phase plus a nuetral. Near the location of the new compactor is an unused welding/charging receptacle. Three #8's and a #10 ground. In the conduit feeding the receptacle are three more #10's that used to feed another three phase receptacle, no longer in use. The person who owns the contracting company that does work in my facilities yelled at the guys doing the work that they should have just used the three #10's as the nuetral required for the compactor. I couldn't reference the code quick enough to prove this point during the discussion/argument. Thanks again for the reference and clarification.

Jazer

 

[jazer]

you cannot parallel anything smaller than 1/0 anyways.

This is the statement I was looking for.