two pole breakers used for single phase loads?

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jcd

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Just returned from a foreign installation. I observed that they have utilized two pole 20A circuit breakers for 120v, single phase lighting circuits. i know, wierd! They have a phase wire and a neutral wire exiting the circuit breaker going to the load. the (japanese) panelboard is configured in such a way that the neutral wire is connected to the CB, and the neutral bus. so, there is no break between the neutral concuctor and the bus.
Here's my question: is there anything in the NEC that requires single pole circuit breakers for single phase 120v loads? Or is it a NEC violation to use a two pole CB for a 120v, single phase load?
 
Re: two pole breakers used for single phase loads?

You might be able to use 110.3(B) to throw a flag on the play. I don?t think that what you describe would comply with the manufacturer?s listing or labeling.
 
Re: two pole breakers used for single phase loads?

I can not see how this would be prohibited by the manufacturer or UL. I do know, the NEC specifically allows the grounded conductor to be protected/switched by a multi-pole circuit breaker.

There are many international ciruit breakers that look like a 2 pole device but are really 1 OCPD and 1 switch. This is similar to our "switched neutral" breakers except the grounded conductor plugs on to the busbar.


edit:added comments

[ August 05, 2004, 12:34 PM: Message edited by: jim dungar ]
 
Re: two pole breakers used for single phase loads?

For years many manufaturers had 2 pole breakersthat you could remove the dual tripper arms. Square d murray and certain large size ge breakers are usable as such.
 
Re: two pole breakers used for single phase loads?

The only thing the NEC says in RE: to this is that if on the same yoke has to be a simotanious break in the ungrounded conductors.Maybe they had allot of 2 pole breakers lying around :D
 
Re: two pole breakers used for single phase loads?

I am a military spouse currently working on a military base in Okinawa Japan as the Electrical Supervisor of the Facilities Management Branch. Now that that is out of the way :D . It sounds to me like it is an Earth Leakage Breaker, although I have no idea why it would be installated on the building lighting circuit. They are similar to GFCI breakers only they trip at 15 milli-amps (international standard). I have a few pictures of Japanese panels with them installed if anyone is interested.
 
Re: two pole breakers used for single phase loads?

Keep in mind that allot of foreign installations don't use a center tap transformer for dwelling services. and only have a source and return. while most bond the return to earth some do not. in each case there is no neutral. But as Jim has said the NEC does allow the neutral/return to be switched as long as both the source and the neutral/return is switched simultaneously.

230.90(B)
404.2(B) Exception
430.85
430.105
514.11(A)
 
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