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#201431 - 05/31/11 07:56 PM Sharing a neutral
Cinner Offline
Member

Registered: 12/01/04
Posts: 77
Loc: 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 - 05/31/11 10:47 PM Re: Sharing a neutral [Re: Cinner]
twh Offline
Member

Registered: 03/11/04
Posts: 892
Loc: 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).

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#201442 - 05/31/11 10:57 PM Re: Sharing a neutral [Re: twh]
Cinner Offline
Member

Registered: 12/01/04
Posts: 77
Loc: 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?

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#201444 - 06/01/11 09:30 AM Re: Sharing a neutral [Re: Cinner]
jay8 Offline
Member

Registered: 07/28/05
Posts: 183
Loc: 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.

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#201447 - 06/01/11 01:30 PM Re: Sharing a neutral [Re: jay8]
jay8 Offline
Member

Registered: 07/28/05
Posts: 183
Loc: 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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