2 Hots, 1 Breaker?

[aka Larry]

This may or may not sound like a dumb question, but I'd rather ask than get it wrong.

I have the need to run a wire for one circuit in two directions from the panel box. Is it OK to install two hot wires on one breaker? FWIW, it's a 20A circuit using #12 THHN wire.

 

[Charles (in GA)]

Depends on the breaker. This is commonly called "double tapping" but some breakers, such as the Square D Homeline series are made specifically for two wires to be connected to them. A few others also allow two wires, such as Square D QO breakers.

The way you can tell is to look at the wire size and terminal torque information on the breaker itself. I have a Square D QO breaker that says on the tiny white placard above the terminal screw "Type QO 120/240V AC.... 1 pole torque 35 LB-IN..... 1 or 2 AL/CU 8-14 wire"

The "1 or 2" is referring to the number of wires allowed.

If you cannot do this, simply run a 4 to 6 inch pigtail from the breaker, and wirenut it to the two wires you are running out of the panel.

Charles

 

[Mickey O]

Is it OK to install two hot wires on one breaker?

No, unless the breaker is specifically design for that purpose.

 

[rlitman]

No, unless the breaker is specifically design for that purpose.

Correct, and the only breaker I'm familiar with that allows for this, is the SquareD QO.

You can run a pigtail from the breaker, and splice in the two lines inside your main panel with a wirenut, but it is generally considered bad form to use your main panel for splicing.
Better than this, you could connect a box to your main panel with a chase ******, and do the splicing in that box. This keeps the mess in your main panel to a minimum.

 

[Vegaman_Dan]

Doubletapping is usually against code and will fail an inspection later when it is caught.

 

[EOC_Jason]

Better than this, you could connect a box to your main panel with a chase ******, and do the splicing in that box. This keeps the mess in your main panel to a minimum.

^^^^ I would do that, but not stick the box *right* next to your panel as I'm sure it is cluttered enough with all the incoming wires.

I would never double-tap in the breaker box as most areas prohibit that, but also down the line if someone starts disconnecting wires then you can get in a can or worms.

Play it safe, run to a separate box and split out your two directions from there tieing it all together with wire-nuts.

 

[Gooch]

Correct, and the only breaker I'm familiar with that allows for this, is the SquareD QO.

You can run a pigtail from the breaker, and splice in the two lines inside your main panel with a wirenut, but it is generally considered bad form to use your main panel for splicing.
Better than this, you could connect a box to your main panel with a chase ******, and do the splicing in that box. This keeps the mess in your main panel to a minimum.

The Homeline series of SqD does aswell as some newer GE's

Doubletapping is usually against code and will fail an inspection later when it is caught.

Do you have a code section to back this up? The code doesn't deal in 'usually'.

 

[EOC_Jason]

Do you have a code section to back this up? The code doesn't deal in 'usually'.

Things like that will vary by county or municipality... Heck even by fire marshall... Point being, if you just do it the more traditional way then there won't be any issues down the road.

 

[rlitman]

The Homeline series of SqD does aswell as some newer GE's

Hum, I never dealt with the Homeline. Haven't seen this from GE either, but what do I know. SquareD has made it a selling point, but IMHO, it still adds to clutter in the main panel.

I only mentioned attaching a box right to the main panel, to fix a situation where the incoming wires come in from opposite directions, and meet at the panel. You could fix everything up with this, without having to extend one of the wires. Yes, it does eat up valuable knockout space on the panel, BUT you could conceivably use other knockouts on the box too.
In commercial installs, this is par for the course. Run a large conduit or two from your panel, just a couple of feet (usually up) to a splicing box, and have every wire head up there. You could even use that to move the ground bus bar out of the panel into there to free up even more space in the panel (with a large enough copper wire leading from that, to the ground point in the panel).

 

[ishiboo]

Things like that will vary by county or municipality... Heck even by fire marshall... Point being, if you just do it the more traditional way then there won't be any issues down the road.

I think you'll be hard pressed to find an example of a municipality that prohibits this for devices which are designed for it. Perhaps there are some inspectors who are confused by it, but there are also inspectors who think splices aren't allowed in the gutter.

IMO double-tapping a breaker is fine when it's done within reason, you could easily make the box just as nasty filling it with tandems.

 

[Aceman]

Like said above, if it's a Sq D, two wires on one breaker is allowed. Otherwise use a small pigtail and wirenut to the two circuit wires. Adding a box just to splice in when you have a perfectly good panel you can do it in doesn't make sense....

 

[Mickey O]

It is a violation of the electrical code (and a dumb thing to do) to double tap a breaker that is not specifically designed to be double tapped, period, end of story.

Now if you live somewhere that doesn't have an electrical code (there are some places), double tap to your hearts content but be sure to have fire insurance, just in case.

When you have a breaker that is rated to accept two wires (double tap), those to wires must be the same size.

For example:

You have a 20 amp breaker with 12 awg wire hooked up to it and a 15 amp breaker with 14 awg hooked up to it and you need and extra slot to put in a 220 breaker. So you get a 15 amp double tap breaker and hook up the 12 awg and the 14 awg wire to it, seems fine both wires can are acceptable for the 15 amp breaker but you can't do it because both the wires have to be the same gauge, either both 14 awg or both 12 awg, etc.

 

[pattenp]

ishiboo didn't say it was okay to double tap a breaker that was not designed to be double tapped.

Alrighty then, I'll just toss my code book out the window and refer any inspector that has a problem with double tapping to you.

It is a violation of the electrical code (and a dumb thing to do) to double tap a breaker that is not specifically designed to be double tapped, period, end of story, there is no with in reason.

Now if you live somewhere that doesn't have an electrical code (there are some places), double tap to your hearts content but be sure to have fire insurance, just in case.

When you have a breaker that is rated to accept two wires (double tap), those to wires must be the same size.

 

[Mickey O]

ishiboo didn't say it was okay to double tap a breaker that was not designed to be double tapped.

Possibly my mistake, I thought he was saying double tapping a regular breaker "within reason" was acceptable, it's not. If you have a box full of breakers designed for double tapping you can double tap all of them. I'll edit the post.

 

[Charles (in GA)]

When you have a breaker that is rated to accept two wires (double tap), those to wires must be the same size.

As far as the physical aspect of two wires of same or different sizes, due to its design, the Square D Homeline doesn't care if the size or type (solid and stranded) are different. It uses a plate with two V notches in it and the screw sits between the notches, kinda like a back wire commercial receptacle.

Now putting two wires under the same screw, like the QO breakers, reason would lead you to believe that they should be the same (tighten down on larger wire, smaller wire is not pinched and comes loose), but that is not indicated on the QO breaker.

Charles

 

[pattenp]

No foul... I read his okay to double tap remark as being in context with him talking about breakers designed to be double tapped. We'll let him clarify.

Possibly my mistake, I thought he was saying double tapping a regular breaker "within reason" was acceptable, it's not. If you have a box full of breakers designed for double tapping you can double tap all of them. I'll edit the post.

 

[Mickey O]

As far as the physical aspect of two wires of same or different sizes, due to its design, the Square D Homeline doesn't care if the size or type (solid and stranded) are different. It uses a plate with two V notches in it and the screw sits between the notches, kinda like a back wire commercial receptacle.

Now putting two wires under the same screw, like the QO breakers, reason would lead you to believe that they should be the same (tighten down on larger wire, smaller wire is not pinched and comes loose), but that is not indicated on the QO breaker.

Charles

I just looked up the Square D Homeline, looks like on those you can use different size gauge wire within the size listed on the breaker but it looks like both wires have to be copper (interesting).

 

[Displaced Hokie]

My box uses Homeline breakers, and it caught my eye last week that the terminal for the wire specifically has two sets of indentions in it for two wires. First breaker I've ever seen like that...and I had planned to double tap it before seeing this thread. I've got the same conditons - wires gotta go different directions.

 

[Speedy Petey]

Doubletapping is usually against code and will fail an inspection later when it is caught.

You CANNOT "fail" a home inspection.

 

[Speedy Petey]

^^^^ I would do that, but not stick the box *right* next to your panel as I'm sure it is cluttered enough with all the incoming wires.

IMO this is nuts, when a simple wire nut in the panel will do it MUCH cleaner, simple and easier.

 

[Charles (in GA)]

^^^^ I would do that, but not stick the box *right* next to your panel as I'm sure it is cluttered enough with all the incoming wires.

...snip....

Play it safe, run to a separate box and split out your two directions from there tieing it all together with wire-nuts.

IMO this is nuts, when a simple wire nut in the panel will do it MUCH cleaner, simple and easier.

I agree, nothing prohibits a wire nut in a panel, un-necessary boxes and conduit is ridiculous, and adds to the clutter.

 

[aka Larry]

Thanks for all the info guys!

 

[pattenp]

Wire nuts that is. Sorry, couldn't resist.

IMO this is nuts, when a simple wire nut in the panel will do it MUCH cleaner, simple and easier.

 

[Falcon67]

Wire nuts that is. Sorry, couldn't resist.

I did double up on the circuit run to the AC unit. The breakers are made for double, so that part is OK. I ran a short piece of 14 up 3' from the panel so I could mount my 30w EXIT sign above the panel next to the door. It has a pull chain switch on it. You can banish me to Lazytown now.

 

[rlitman]

I agree, nothing prohibits a wire nut in a panel, un-necessary boxes and conduit is ridiculous, and adds to the clutter.

In a residential install, no nothing prohibits this. And if you have a brand spanking new panel with lots of space all around, it sure is a valid option.

BUT it still wreaks of poor worksmanship, and in an older panel with limited wiring space, it can get difficult to hide the wirenut, and the extra wires make it even harder to see (let alone get to) the neutral bar, which may already be lacking on free spaces.

 

[Speedy Petey]

BUT it still wreaks of poor worksmanship, and in an older panel with limited wiring space, it can get difficult to hide the wirenut, and the extra wires make it even harder to see (let alone get to) the neutral bar, which may already be lacking on free spaces.

Sorry, but I have to strongly disagree here (I know, big surprise, right?).

I certainly does NOT reek of poor workmanship. How can you possibly justify this statement? It's a wire nut for goodness sake. Why would you need to "hide" it??

And the added wire? The two wires are already in there. How is that different than splicing outside the panel and bringing in a new longer wire????

I've heard this opinion before and for the life of me I just don't get it.

 

[rlitman]

And the added wire? The two wires are already in there. How is that different than splicing outside the panel and bringing in a new longer wire????

I've heard this opinion before and for the life of me I just don't get it.

It is four extra wires, and two extra neutral bar spaces.

Splice in panel:
Hot #1
Hot #2
Hot Pigtail
Neutral #1
Neutral #2
Ground #1
Ground #2
that's 7 wires by my count.

Splice outside of panel and you just have a single hot, neutral, and ground.
That is 3 wires.

If you go to the store, and buy a panel today, it may be no big deal. Their neutral bars have extra slots. A panel from the 80's may have a neutral bar with only as many holes as breaker slots, and it had several inches less working space on each side.

 

[Speedy Petey]

It is four extra wires, and two extra neutral bar spaces.

Splice in panel:
Hot #1
Hot #2
Hot Pigtail
Neutral #1
Neutral #2
Ground #1
Ground #2
that's 7 wires by my count.

Splice outside of panel and you just have a single hot, neutral, and ground.
That is 3 wires.

If you go to the store, and buy a panel today, it may be no big deal. Their neutral bars have extra slots. A panel from the 80's may have a neutral bar with only as many holes as breaker slots, and it had several inches less working space on each side.

All you are doing is splicing the two hots. The others are all on the ground/neutral bars.

Whatever, it is not a problem that some of us disagree. Our differences are what make us special.

 

[ishiboo]

Possibly my mistake, I thought he was saying double tapping a regular breaker "within reason" was acceptable, it's not. If you have a box full of breakers designed for double tapping you can double tap all of them. I'll edit the post.

Definitely not... I was only saying there is no reason not to do it (since the NEC allows it) on devices which are rated for it.

I just looked up the Square D Homeline, looks like on those you can use different size gauge wire within the size listed on the breaker but it looks like both wires have to be copper (interesting).

Probably not that interesting... copper and aluminum expand/contract very differently... the aluminum wire with a big load on it could probably work the whole thing loose. The diameters would also be different for the same load.

Splice outside of panel and you just have a single hot, neutral, and ground.
That is 3 wires.

If you go to the store, and buy a panel today, it may be no big deal. Their neutral bars have extra slots. A panel from the 80's may have a neutral bar with only as many holes as breaker slots, and it had several inches less working space on each side.

If you're going to stuff the panel full of ****, you're going to stuff the panel full of ****... that's independent of having two wires on one breaker.

How is having a couple breakers double-tapped any different from having a couple tandems in the panel?

I used to split my smoke alarm circuit with a double-tapped breaker, since it's split up into two distinct sections of the house, and there's no reason to have two breakers for .00005 amps of current. However... I switched it to a separate box now because I broke out the signal wire for an alarm relay.

 

[rlitman]

Definitely not... I was only saying there is no reason not to do it (since the NEC allows it) on devices which are rated for it.
. . .
How is having a couple breakers double-tapped any different from having a couple tandems in the panel?

All this still comes down to what the AHJ has to say.

How is it different? It isn't. But older panels with limited space aren't rated for tandem breakers either, so it wouldn't come up there (let's not get into the debate about non-limited breakers).

 

[ishiboo]

All this still comes down to what the AHJ has to say.

How is it different? It isn't. But older panels with limited space aren't rated for tandem breakers either, so it wouldn't come up there (let's not get into the debate about non-limited breakers).

The AHJ should have nothing to say if it's allowed by the manufacturer and the NEC. As I said, there are exceptions everywhere, but that doesn't change the nationwide, 99.9% of the time code that applies to the vast majority of us here.

As I said, a stuffed panel is a stuffed panel no matter how you get there. That doesn't mean there is useful validity to a rule like don't double-tap a breaker which is rated for it with sufficient space in the panel.

 

[EOC_Jason]

LOL...

I once tried to argue with the county that someone was doing something grossly unsafe and pointed out that it severely violated IBC, not to mention had several engineers give statements about the situation... The county's response, "We don't follow IBC."

Yeah...