Neutrals

[ken44]

I have a 3 phase supply system, I am installing branch circuits, I use one neutral per 3 phases;A,B,C. But what if the blueprints call for 6 circuits, 3 which are phases A,B,C and 3 which are phases A,A,A, can I still use one neutral for these 3 phases and if not, then why?

 

[iwire]

Re: Neutrals

Originally posted by ken44:
3 which are phases A,A,A, can I still use one neutral for these 3 phases and if not, then why?

No, the current from each phase A circuit will add up on the neutral.

If three hots of the same phase each had 15 amps of load on them the neutral would have 45 amps of load.

When you have phase A, B, C each with 15 amps of load the neutral will have 0 amps on it.

 

[jimwalker]

Re: Neutrals

You could change there circuit numbers so they are abc abc but get the ok from engineer first.Then only 2 nutrals needed.Keep them in pairs.We do this often here.

[ October 22, 2004, 05:32 AM: Message edited by: jimwalker ]