Handle Ties or Double Pole Breaker for Multiwire Branch Circuit

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gadfly56

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New Jersey
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Professional Engineer, Fire & Life Safety
The CMP feels differently.

This is from the 2008 ROP and makes clear that the CMP does not feel the source is the OCPD. I will admit It does show other people have some confusion on it though.








No, that would not be at the source that would be a 100' away.

Think of it the same way as 'nearest the point of entrance'




I am not going to change my mind, the CMP sees it like I do (or I see it like they did) OTH what you are suggesting is not supported by the words in the section.

Sounds like an expansion is needed, something along the lines of "not more than 6 feet from the OCPD". That would cover it for sure. FWIW I think a multi-pole snap switch next to the panel is fine, but to clarify the intent some boundary should be set.
 

jumper

Senior Member
Appreciate all the professional opinions. The AHJ allowed the use of a DP breaker. To comment on the statement if the NEC doesn't say you can't then you can didn't work here in NC. We used an open top trough on a hotel installation and he (AHJ) rejected it. Department of Insurance agreed and said open top troughs are not permissible, only open bottom where the NEC says you can. The NEC is clear as mud.

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Worked on a large grocery store and the strip shops that go with it in Raleigh and never had any real problems there.
 

Dennis Alwon

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Location
Chapel Hill, NC
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Retired Electrical Contractor
The CMP feels differently.

This is from the 2008 ROP and makes clear that the CMP does not feel the source is the OCPD. I will admit It does show other people have some confusion on it though

All that is saying is if the multiwire branch circuit starts outside the panel then a switch can be used, IMO

No, that would not be at the source that would be a 100' away.

Think of it the same way as 'nearest the point of entrance'

And where does this info come from-- That is you reading into it. Nothing in the wording states what you are saying-- not that I don't agree with you in terms of common sense but that is not what it says.



I am not going to change my mind, the CMP sees it like I do (or I see it like they did) OTH what you are suggesting is not supported by the words in the section.

I am not convinced the cmp is clear on what they mean so again neither of us is going to change their mind...:p
 

roger

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Location
Fl
Occupation
Retired Electrician
Does the branch circuit originate on the bus or the enclosure? If I were the inspector I would interpret it to mean bus. If someone had another way to disconnect the conductors on the bus besides an OCPD then all is well.

JMHO

Roger
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Does the branch circuit originate on the bus or the enclosure? If I were the inspector I would interpret it to mean bus. If someone had another way to disconnect the conductors on the bus besides an OCPD then all is well.

JMHO

Roger


Exactly...

Bob the fact that the cmp states the disconnect does not have to a overcurrent protective device means it could be a switch on the bus. It is also possible for 2 -- 2 wire branch circuits that connect up to a 3 wire multiwire branch circuit. At that point a switch would be the disconnect.

Quite frankly I cannot believe you are really not seeing that in most cases the overcurrent protective device is the origin of the circuit. You state things like "as near as possible" for the disconnect yet there is no code to back up what you stated. It appears you are trying to make your interpretation be the right one but IMO you have not backed it up.

Maybe I am missing something but I don't think so
 

ADub

Senior Member
Location
Midwest
Occupation
Estimator/Project Manager
Appreciate all the professional opinions. The AHJ allowed the use of a DP breaker.

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Well I'd certainly hope so co did wrong it's explicitly nec compliant. Sounds like your inspector needs some educating.


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ADub

Senior Member
Location
Midwest
Occupation
Estimator/Project Manager
Well I'd certainly hope so co did wrong it's explicitly nec compliant. Sounds like your inspector needs some educating.


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Butchered by autocorrect. I was trying to say I'd certainly hope so since its explicitly nec compliant yada yada


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