Handle Ties or Double Pole Breaker for Multiwire Branch Circuit

Transportation Guy

Senior Member
Location
Williamsburg,VA
Good afternoon. We are having to install some handle ties for some existing panels. Section 240.15.B.1 states "Individual single pole circuit breakers with identified handle ties shall be permitted as the protection for each ungrounded conductor of multiwire branch circuits. " I dont see where it says a 2 pole is permissible. However I have seen many drawings showing 2 pole breakers as acceptable. If I have 2ea branch circuits @120vac sharing a neutral, can they be protected on a 2 pole breaker versus 2 singles with handle ties? I have never used them but have seen this done. I dont see in the NEC where it is permissible.
 

Transportation Guy

Senior Member
Location
Williamsburg,VA
Thanks Dave. I see that but reading item 1 which references multi wire branch circuits, it doesn't say a 2 pole can be utilized in a multi wire branch circuit. I'm going to speak with our AHJ. If the book doesn't specifically state it, he doesn't allow it.

Sent from my SM-N920V using Tapatalk
 

jumper

Senior Member
Thanks Dave. I see that but reading item 1 which references multi wire branch circuits, it doesn't say a 2 pole can be utilized in a multi wire branch circuit. I'm going to speak with our AHJ. If the book doesn't specifically state it, he doesn't allow it.

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That MWBC section says "permitted", an allowance from the "shall" below.

(B) Circuit Breaker as Overcurrent Device.
Circuit breakers shall open all ungrounded conductors of the circuit
both manually and automatically unless otherwise permit-
ted in 240.15(B)(1), (B)(2), (B)(3), and (B)(4).
I am at a loss as how you do not see this applies to a 2P breaker.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
Check this out

210.4(B) Disconnecting Means. Each multiwire branch circuit
shall be provided with a means that will simultaneously
disconnect all ungrounded conductors at the point where
the branch circuit originates.
Informational Note: See 240.15(B) for information on the
use of single-pole circuit breakers as the disconnecting means.
 

iwire

Moderator
Staff member
Location
Massachusetts
Thanks Dave. I see that but reading item 1 which references multi wire branch circuits, it doesn't say a 2 pole can be utilized in a multi wire branch circuit. I'm going to speak with our AHJ. If the book doesn't specifically state it, he doesn't allow it.

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Consider this, MWBCs are installed from old fuse panels as well. In those cases you would have to put a double or triple pole switch beside the panel. It's for reasons like this the code allows other methods than handle ties.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
Consider this, MWBCs are installed from old fuse panels as well. In those cases you would have to put a double or triple pole switch beside the panel. It's for reasons like this the code allows other methods than handle ties.

Bob where is the exception to allow a dp or 3 pole switch- I assume you mean snap switch
 

iwire

Moderator
Staff member
Location
Massachusetts
Bob where is the exception to allow a dp or 3 pole switch- I assume you mean snap switch
Or any means.

210.4(B) Disconnecting Means. Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates.
Why would I need an exception? I would be doing exactly what it asks of me.
 

iwire

Moderator
Staff member
Location
Massachusetts
How does a dp switch disconnect the power when a breaker trips. The dp breaker does not disconnect the all the conductors since the breaker feeds the switch
Having all circuits open during a fault is not what is required.

The means of disconnection is all about servicing the circuit, it has nothing to do with the overcurrent protection of the circuit.
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
While I know it's not code and I've been allowing it anyway, the handbook says, "....two single-pole circuit breakers with an identified handle tie or a two-pole circuit breaker...."
 

GoldDigger

Moderator
Staff member
While I know it's not code and I've been allowing it anyway, the handbook says, "....two single-pole circuit breakers with an identified handle tie or a two-pole circuit breaker...."
The handbook ID redundant, which is allowed.
Since (B) allows a multipole breaker there is no need to mention it in what amounts to an exception, that is (1).

Actually it is more of a clarification than an exception, since IMO (B) already allows both.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
IMO if that is what they meant that is what it would say.

Is it your position a MWBC cannot originate from a fuse panel?

Bob you posted this

210.4(B) Disconnecting Means. Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates.
 

jaggedben

Senior Member
If you ask me, the bar connecting the two poles of most two-pole breakers is a handle tie. It's kind of ridiculous to suggest otherwise.

(I would say I've never seen a 2-pole breaker without a handle tie, but recently my guys brought an old QO back from a jobsite that was two full-space handles in one housing, not tied together, and clearly said 'common trip.' So never say never, I guess. That breaker was probably 40 years old.)
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Electrical Contractor
While I know it's not code and I've been allowing it anyway, the handbook says, "....two single-pole circuit breakers with an identified handle tie or a two-pole circuit breaker...."

We are not talking about ties on sp breakers nor dp breakers but a dp switch after the overcurrent protective device. I think so anyway
 
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