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Discussion Starter #1
Forgive me if this has been answered before, but I see postings on home inspection forums that say something to the effect that "no breaker can have two wires on it" and then gives the advice that if such a condition exists, that "a pigtail should be run to the breaker, and the two wires now going to the breaker should be connected to the pigtail with a wire nut." I have been looking at quite a few panels in the last few weeks, and many have this issue. I don't want to tell people they should have things changed unless this change is necessary, and would like to know why the breaker manufacturers say in their directions that their devices are designed for use with one OR two wires.

I just checked on Square-D QO series on the Square D website, and they say that two conductors on one breaker is okay. Are the two-wires on one breaker rule something new, something that is selectively enforced, or something that maybe is permissable in some commercial or industrial environments, but not in homes.
 

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Sparky
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706 Posts
Most breakers are NOT identified for 2 wires, under the same screw.

A lot of newer Square D breakers are identified for 2 wires.


EDIT. See NEC 110.14(A)
 

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Licensed electrician
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13,379 Posts
It is a matter of how the makers ask UL to test their breakers.

Bothe the Square D Homeline and QO series in the 15-30 amp sizes will accept 2 conductors. Some C-H Classic Brown will also accept 2.

Even the older SqD QO were listed for 2 conductors. Look on the breaker side for the acceptable number and sizes.
 

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Scared Electrician
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the advise you get from home inspectors is incomplete at best. As a golden rule: yes they are correct- breakers aren't supposed to have more than one wire, BUT they never mention the exception- if listed. SO in most cases it is a code violation and the wire should be pigtailed- something they also tell you you can't do (which is complete BS) However a lot of the newer breakers are allowing it.
 

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A breaker that accepts two wires will have ridges or grooves or a retaining washer that holds two wire ends in place fully under the screw head without wrapping them around the screw shank and just before the screw is tightened.
 

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Licensed Electrical Cont.
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As a golden rule: yes they are correct- breakers aren't supposed to have more than one wire, BUT they never mention the exception- if listed.
This is actually not technically true. There is no rule that breakers are not supposed to have more than one wire, and there is no "exception" that allows it.

Jim Port's post and Techy's NEC reference of NEC 110.14(A) are dead on.
 

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This is actually not technically true. There is no rule that breakers are not supposed to have more than one wire, and there is no "exception" that allows it.

Jim Port's post and Techy's NEC reference of NEC 110.14(A) are dead on.
Speedy, doesn't the following imply that a terminal not identified as accepting more than one conductor must be used with only one conductor?

NEC 110.14(A) said:

Terminals for more than one conductor and terminals used to connect aluminum shall be so identified.
 

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Don't know it all, yet!
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sirsparksalot,
Seems that common sense would lead you to think that.

I'm not an electrician but I can tell you that if my dad told me to be quiet and sit down, I didn't have to ask for how long. Common sense told me not to get up until he told me to. Well, that and the misfortune of having gotten back up one time.:(
 

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sirsparksalot,
Seems that common sense would lead you to think that.

I'm not an electrician but I can tell you that if my dad told me to be quiet and sit down, I didn't have to ask for how long. Common sense told me not to get up until he told me to. Well, that and the misfortune of having gotten back up one time.:(
I understand, downunder, but I don't think Speedy would consider my question as second-guessing him. I trust, but like to verify. :)
 
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