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Cornhusker Joe 12-21-2012 01:22 AM

splice in breaker panel
 
I got a little carried away in the earlier part of my wiring project, thinking I could never use all available slots for breakers because it is a modest sized home. Now that I'm down to the last room, the kitchen, I am 1 slot short and have decided I need to combine two circuits. I ran 4 20A circuits to outdoor GFI receptacles and I now know that was overkill. i want to combine 2 to free up a slot. I understand pigtailing the hot from the breaker, but do I need to pigtail the nuetrals, or can I leave them as they are conncted to the nuetral buss?
Thanks guys.
Joe

kbsparky 12-21-2012 07:26 AM

No need to pigtail the neutrals. Also, if you have Square D breakers, you can legally terminate 2 conductors on a breaker without having to pigtail.

AllanJ 12-21-2012 09:42 AM

You may not pigtail two branch circuits' neutrals (grounded conductors) to become one because you ran out of holes in the neutral bus bar. You may not put two neutrals into one hole.

But you may pigtail two or more branch circuit ground wires (equipment grounding conductors) to become one, say, to free up holes in the bus bar. The pigtail itself must be of the size of the larger(est) EGC. Also you may put two EGCs of the same size into one hole, not criss crossing. (The set screw will probably not hold both in place if they are of different sizes.)

Some jurisdictions do not permit pigtailing (and splicing) in the panel, even one for one so as to extend an otherwise too short wire). This is sorta' silly since you would end up withdrawing the branch circuit cable from the panel, installing a junction box nearby, and adding a sufficiently long cable to continue on to the panel.

Some jurisdictions do not allow circuit conductors to pass through a panel, including conductors in conduits entering and then exiting with no splice, while permitting splicing on a pigtail to extend a too short wire.

(added later) For two incoming cables to be served by one breaker (technically being one branch circuit), pigtailing the neutrals is optional, although if the cables are assigned to separate breakers later, the neutrals will need to be given their own holes in the bus bar.

The significance of required pigtailing of neutrals applies to outlet boxes and when dealing with a feed and a downstream continuation, which is not the case in the panel here. In an outlet box, if the feed and continuing hot are connected directly to each other, then their corresponding neutrals must be connected directly to each other with a pigtail as needed to reach the receptacle or other device in the box. This prevents leaving the two neutral ends loose while the hot wires remain connected should the receptacle be removed for some reason or other. If the power was on and a light downstream remained switched on, the continuing loose neutral end would end up hot.

philS 12-21-2012 10:22 PM

pigtailed neutrals?
 
Hmm, I have two #12 neutrals pigtailed in my panel (using a #10 pigtail). My inspector has been up to his wrists in the box at least 3 times and has never said anything. The wire nut and pigtail are right out in the open so i doubt he just missed them. What's the logic here behind not doing this? I did it obviously because I'm out of neutral holes and we're not allowed to double-lug neutrals. Grounds yes, but not neutrals.

k_buz 12-21-2012 10:27 PM

You can pigtail neutrals if the associated hots are also pigtailed.

Cornhusker Joe 12-21-2012 10:57 PM

Thanks guys. It is a Square D panel, so being able to connect 2 hots to 1 breaker makes it even easier. When I started this project I never thought I could ever, ever, fill the panel. When I'm getting down to the end I needed 1 more space. The cover over the breakers has more knockouts than spots on the buss bars, so I was thinking I had a couple of extra spaces.
All better now, thanks for the help.
Joe

philS 12-22-2012 06:53 AM

Quote:

Originally Posted by k_buz (Post 1077758)
You can pigtail neutrals if the associated hots are also pigtailed.

Unfortunately that makes perfect sense. Thanks.

AllanJ 12-22-2012 08:03 AM

Quote:

Originally Posted by philS (Post 1077754)
Hmm, I have two #12 neutrals pigtailed in my panel (using a #10 pigtail). My inspector has been up to his wrists in the box at least 3 times and has never said anything. The wire nut and pigtail are right out in the open so i doubt he just missed them. What's the logic here behind not doing this? I did it obviously because I'm out of neutral holes and we're not allowed to double-lug neutrals. Grounds yes, but not neutrals.

Why we don't pigtail neutrals of different branch circuits entering the panel, or double-lug neutrals on the panel bus:
1. To avoid overloading the neutral (the pigtail itself). (Some folks don't upsize the neutral pigtail.)
2. To avoid accidentally unhooking a neutral of a circuit that was not being worked on and was still powered on.

Your inspector might not know the limitations of pigtailing neutrals in the panel and for that reason let it go.

If you unhook the neutral pigtail serving two branch circuits and one circuit is still powered on with devices switched on then both circuits' neutrals up through the pigtail and possibly the other circuit hot wires will be live. This can catch many folks by surprise starting with the spark that is seen when the neutral is unhooked considering that many folks incorrectly equate neutral with ground.

philS 12-22-2012 11:16 AM

Quote:

Originally Posted by AllanJ (Post 1077865)
Why we don't pigtail neutrals of different branch circuits entering the panel, or double-lug neutrals on the panel bus:
1. To avoid overloading the neutral (the pigtail itself). (Some folks don't upsize the neutral pigtail.)
2. To avoid accidentally unhooking a neutral of a circuit that was not being worked on and was still powered on.

Your inspector might not know the limitations of pigtailing neutrals in the panel and for that reason let it go.

If you unhook the neutral pigtail serving two branch circuits and one circuit is still powered on with devices switched on then both circuits' neutrals up through the pigtail and possibly the other circuit hot wires will be live. This can catch many folks by surprise starting with the spark that is seen when the neutral is unhooked considering that many folks incorrectly equate neutral with ground.

Thanks. It always good to explain this stuff.

As for my inspector, I'm sure he saw it. But we had bigger fish to fry. Reality is after 22 years of changing this and that, and two major additions to the house (built 1975), the entire service entrance panel and cable need to be completely redone. Major aspects of it are not up to current code. Inspector is letting me grandfather the issues for now but next year I'm hoping to have time to redo it completely.

dbooksta 12-22-2012 12:33 PM

Assuming we're talking about wires of the same gauge and type, can somebody clarify:

1. Which breakers allow termination of two conductors on the breaker itself? Or how can you tell when that's legal? And why would it be legal for some but not others? (I have CH breakers and panel.)

2. If you are terminating two conductors on the breaker then is it also legal to terminate the associated neutrals in the same hole on the neutral bar?

3. Confused by @PhilS practice: If you're pigtailing conductors to the same breaker does the pigtail have to be stepped up in capacity? I assumed that if we're pigtailing two #12 conductors to a 20-amp breaker the pigtail can also be #12, since the whole circuit is still limited to 20 amps.

tylernt 12-22-2012 12:39 PM

Quote:

Originally Posted by Cornhusker Joe (Post 1077771)
The cover over the breakers has more knockouts than spots on the buss bars, so I was thinking I had a couple of extra spaces.

Ugh, I found that out too. 20 slot panelboard under a 24 slot deadfront. So annoying! Square D has other annoying things too, like some of their meter/main enclosures have no factory interlock kit available, even years after they started making them. :furious:

tylernt 12-22-2012 12:44 PM

Quote:

Originally Posted by dbooksta (Post 1077995)
1. Which breakers allow termination of two conductors on the breaker itself?

On Square D, you can look at the connector and it has two slots in the plate under the screw.

Quote:

And why would it be legal for some but not others?
It's only legal if the panel manufacturer designed it for double-lugging AND had a nationally recognized independent lab test it and approve it and list it for that purpose (such as the UL, Underwriters Laboratory).

philS 12-22-2012 02:07 PM

Quote:

Originally Posted by dbooksta (Post 1077995)
Assuming we're talking about wires of the same gauge and type, can somebody clarify:


3. Confused by @PhilS practice: If you're pigtailing conductors to the same breaker does the pigtail have to be stepped up in capacity? I assumed that if we're pigtailing two #12 conductors to a 20-amp breaker the pigtail can also be #12, since the whole circuit is still limited to 20 amps.

dbooksta - Good question. I wasn't clear about what I did. First, it's definitely NOT my practice but I had no choice, other than to replace the panel. I'm completely out of neutral lugs, even with a 10-lug add-on. So now I have two separate 20-A circuits combined onto one neutral pig-tail. Potentially, that's 40A, though it will never happen.

Now that I think about it more, it's possible they're on opposite phases, in which case the pig-tail will be unlikely to see even 20 A. But I didn't think about that, just up-sized the pigtail to #10.

As I said, this is ONLY temporary. And if anyone other than me is going to work on the panel, I will definitely warn them about what I did.

What you're talking about, bringing two home-runs into the panel and combining them on one breaker is, AFAIK, perfectly ok. Obviously they have to not, in combination, draw more than the beaker is rated for. Realistically, when you start to max out in your panel, and if you have some dedicated lighting circuits, combining them into one breaker may be a quite good way to free up a slot. Obviously, tandem breakers are an even better way but that's precisely why I've run out of neutral lugs.

Anybody see errors in what I just said, you know what to do. I'm here to learn.

Dave632 12-22-2012 03:26 PM

Quote:

Originally Posted by philS (Post 1078052)
dbooksta - Good question. I wasn't clear about what I did. First, it's definitely NOT my practice but I had no choice, other than to replace the panel. I'm completely out of neutral lugs, even with a 10-lug add-on. So now I have two separate 20-A circuits combined onto one neutral pig-tail. Potentially, that's 40A, though it will never happen.

...

But all it has to do is exceed 20A to be beyond the capacity of a #12 pigtail. I'd leave the #10 pigtail in place (unless you're sure they're on different sides of the split-phase service).

Jim Port 12-22-2012 04:32 PM

Quote:

Originally Posted by dbooksta (Post 1077995)
Assuming we're talking about wires of the same gauge and type, can somebody clarify:

1. Which breakers allow termination of two conductors on the breaker itself? Or how can you tell when that's legal? And why would it be legal for some but not others? (I have CH breakers and panel.)

Square D and Cutler-Hammer CH are two brands that do in the 15, 20 and 30 amp versions

Quote:

2. If you are terminating two conductors on the breaker then is it also legal to terminate the associated neutrals in the same hole on the neutral bar?
No, one neutral per hole, regardless.


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