Mutli-wire circuit circuit breaker
- Thread starter olc
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JeffBabineaux
Member
- Location
- Minden, LA
False. 240.15(B)(1) allows for single-pole circuit breakers, as long as it can still be simultaneously disconnected 210.4(B). The 2011 handbook has an example of this for a single phase installation using two single-pole circuit breakers with a common neutral. Make sure it has an identified handle tie for all connected breakers.
- Location
- Connecticut
- Occupation
- Engineer
luckylerado
Senior Member
- Location
- Lake of the Ozarks
True. 3 pole breaker or single pole breakers with handle ties
- Location
- Connecticut
- Occupation
- Engineer
Wouldn't the part in red make the question false?
luckylerado
Senior Member
- Location
- Lake of the Ozarks
IMO the handle tie makes it mulitpole.
- Location
- Massachusetts
Absolute not.
A multipole breaker is factory built with an internal common trip. With a multipole breaker a short circuit on one pole will always open all poles.
On the other hand two or three single pole breakers with handle ties will not open all poles due to a short on one pole. This is due to the required 'trip free' design of breakers.
- Occupation
- Licensed Electrician
Absolutely right.
mwm1752
Senior Member
- Location
- Aspen, Colo
- Location
- Connecticut
- Occupation
- Engineer
Still false. A 3 pole circuit breaker can be a simultaneous disconnect, but so can three single pole circuit breakers with a handle tie.
A 4 conductor mwbc does not NEED to be connected to a 3 pole circuit breaker.
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
And just FWIW, a three pole circuit breaker does not HAVE to be common trip. Almost all of them are though.
A single two pole breaker with handle ties but without common trip is often found as part of quad breaker sets.
- Location
- Massachusetts
Can you post an example?
luckylerado
Senior Member
- Location
- Lake of the Ozarks
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Probably not (in terms of three pole low voltage consumer breakers.)
But they exist at the utility distribution level. http://www.iso-ne.com/rules_proceds...eakers_used_for_independent_pole_tripping.pdf
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
If the question had asked if a 3 pole breaker could be used then the answer would be Yes but saying that it needs to be a 3 Pole is incorrect. However if this is a test it is no telling what the test making may want as an answer
mwm1752
Senior Member
- Location
- Aspen, Colo
The my statement was true did not insinuate it was the only method availiable (can)
- Location
- Connecticut
- Occupation
- Engineer
The answer to the OP's question cannot be both True and False. It is False.
mwm1752
Senior Member
- Location
- Aspen, Colo
Sure seemed like you were only responding to my statement as false when you used a partial quote. I thought I adressed the OP's statement with the skinning cat verbage as false which means there is more than 1 method to achieve the same goal.
- Location
- Connecticut
- Occupation
- Engineer
I'm not sure I understand your point. There being more than one way to skin a cat doesn't make the OP's question any less false.
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