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#201431 - 05/31/11 10:56 PM Sharing a neutral  
Cinner  Offline
Member
Joined: Dec 2004
Posts: 78
Kelowna, B.C., Canada
On a 3 phase panel - if 2 circuits share a neutral - do you have to use a 2 pole breaker so that if one trips they both trip?


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#201441 - 06/01/11 01:47 AM Re: Sharing a neutral [Re: Cinner]  
twh  Offline
Member
Joined: Mar 2004
Posts: 905
Regina, Sask.
14-010. It depends on whether the circuit feeds lights or plugs.

It isn't a trip issue, though. We can still use fuses as long as we include a disconnect that meets the requirements of 14-010(b).


#201442 - 06/01/11 01:57 AM Re: Sharing a neutral [Re: twh]  
Cinner  Offline
Member
Joined: Dec 2004
Posts: 78
Kelowna, B.C., Canada
It is for receptacles. Can you use 15 amp single pole breakers if the neutrals are being shared to more than one circuit?


#201444 - 06/01/11 12:30 PM Re: Sharing a neutral [Re: Cinner]  
jay8  Offline
Member
Joined: Jul 2005
Posts: 183
Vancouver, BC
the trade practice for three phase 4 wire circuits feeding 120/347 volts loads is single pole breakers. I could see good justification for a three pole breaker to ensure a circuit is completely disconnected included any current on a shared neutral but I dont think any code rule requires it. If the receptacle/load is using more than one phase then you need to use 2 or 3 pole breaker.


#201447 - 06/01/11 04:30 PM Re: Sharing a neutral [Re: jay8]  
jay8  Offline
Member
Joined: Jul 2005
Posts: 183
Vancouver, BC
and before a bunch of posts come about the implications of common breaker handle for single phase loads, I can see some change in installation practice that will reflect the issue of current on shared neutral - such separate neutrals etc



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