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Double Taps


Garcha

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I've been bouncing this idea about double taps around and off of as many electricians as possible. Where do you guys stand on double taps. And if that wasn't enough todays house actually had a triple tap, that worried me... a little. There was enough other stuff like the AL wiring, the 12-2/ 30Amp A/C circuit and open outlet box under the sink. So I was just thinking about this and wondered what you all thought. I wish I could drop the Pics in for you[;)] maybe if someone explained it to me r--e--a--l s--l--o--w, I could get it right for a change.

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The concensus around here is that double-taps are only kosher on the one or two breakers actually designed to accept them (certain Sq. D & Cutler-Hammer models), and triples are never allowed.

Aluminum wiring depends on the details of the situation. Got details?

The #12 30 amp AC circuit is probably fine. The code allows going one size under on those circuits.

The open outlet box is just plain bad, an accident waiting to happen. With a switch no less...you reach in, your finger slips, and....[xx(]

Brian G.

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Originally posted by Garcha

I've been bouncing this idea about double taps around and off of as many electricians as possible. Where do you guys stand on double taps.

Like anything else, I stand slightly to the left and downstage.

And if that wasn't enough todays house actually had a triple tap, that worried me... a little.

OK. Here's the general rule: Breakers are only supposed to hold one wire unless they're identified to hold more than one. Easy to remember, right?

It's a product standard, and it's been that way pretty much forever.

There are three reasons why double taps are a bad thing:

1. Unless the terminal is designed to hold more than one wire, the wires may not make a good connection and they could overheat.

2. It makes it impossible to isolate individual circuits without disconnecting both of them.

3. It may be an indication that the breaker is overloaded.

I've done quite a bit of research on this particular topic and I know of only two brands of breakers that are designed to accept more than one wire. It just so happens that one of them is in your picture. The Cutler Hammer breaker with three wires is a type CH breaker and is designed to accept two (not three) wires. They can be #10-#14, either two of a single size or a combination of two different sizes, and they must be copper, not aluminum. Furthermore, when double tapped, the terminal screw is supposed to be torqued to 30 lb-in. That's pretty tight. Note that the breakers above and below that one are also Cutler Hammer, but are not type CH and are NOT rated for more than one wire.

The other brand is Square D. SOME (not all) of their breakers have terminal screws that tighten a pair of metal saddles that have channels designed to capture two wires, one on each side of the screw. These will accept two wires between #10 and #14. You can use two of the same size or two different sizes. These terminals are supposed to be tightened to 36 lb-in. That's very tight.

With both of these breakers, this information is cast onto the body of the breaker.

There was enough other stuff like the AL wiring,

The stuff in the pictures is copper. You do know that aluminum wiring is only a problem in the 15 and 20 amp ranges, right? Large appliance circuits can be wired with aluminum wihtout any problem.

the 12-2/ 30Amp A/C circuit

Not to pick on you, but the 12/30 AC circuit might be just fine. What did the AC data plate say?

and open outlet box under the sink. So I was just thinking about this and wondered what you all thought.

The missing 99-cent coverplate is the least of the problems in that pic. If I were going to pick on that, I'd be sure to also pick on the fact that the box is improperly mounted (it's an old-work box that's mounted with screws through the back) and that the romex is improperly exposed to physical damage. The box itself may also be damaged where the left yoke is supposed to connect to it.

- Jim Katen, Oregon

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Just adding real life experience here. Double taps are a bad thing and should be called except in breakers like Brian described.

My last home had several breakers double tapped and I planned on replacing the undersized panel. In my normal state of procrastination, I let a few years go by and still hadn't done it and while working in the basement one day I heard a buzzing sound. I narrowed the noise to the panel and pulled the cover about the same time the wires were so hot that the insulation was dripping off of them.

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Sorry, never mind I figured it out. I'm from PA what else can I say.[:-dunce]

I can think of worse States to be from (about 40) and the one you moved to is about at the bottom. [;)] (I went to school in Springfield and have family in Dayton & Cleveland.)

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The CHP 115, 215 & 315 can be used with a solid & standed wire together. I do not know of any CH Breaker that can be used with 2 solids, if there is one I am sure someone will enlighten me.

Why was this question on Double Taps not posted in the Electrical Forum

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Originally posted by monte

The CHP 115, 215 & 315 can be used with a solid & standed wire together. I do not know of any CH Breaker that can be used with 2 solids, if there is one I am sure someone will enlighten me.

Why was this question on Double Taps not posted in the Electrical Forum

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Richard & Jim - I was wrong on my interpretation of this Note 2 on Page 3-21 and 3-25.

I contacted the support center at Cutler-Hammer (DIY Support Center 877-932-9322 option 3) and asked them about my interpretation of the Note 2 on page 3-21 & 3-25 "Solid and stranded wire can be used together". They are going to sub jest to there engineers, a change of the wording to "Solid and/ or stranded wire can be used together" when they redo there Production Selection Catalog for these 15 AMP Circuit Breakers

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Thanks all, Sorry I dropped out for a couple days- it's nice to be working. I thought that the major problem with the double taps was the bad connection and I knew the triple was a bad play. I didn't know they made breakers that accept doubles until you mentioned it and then I remember seing them all over.

Jim I knew about the stranded wire and the A/C was not pulling enough to get full operation out of the compressor which explained the minimal temp drop and a lot of other stuff. Please pick on me all you want I only know what I know and my ego can handle correction from the old silverbacks. [:-dog]

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  • 5 weeks later...
Originally posted by chrisprickett

Does anyone have any documentation regarding the Square D HOM type breaker being ok for double tap? I know it's ok, I just want to have documentation for my records. I don't see anything on the panel, either way

The documentation is cast into the moulded case of every breaker.

Other than that, try here:

- Jim Katen

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Jim,

I appreciate the link, but I had already spent nearly 2 hours trying to find a document that pertains to "double-tapping" an HOM type breaker. I can get installation instructions on just about every type of breaker, but nothing that specifically says you can double tap.

I have pics of the wording on the individual breaker, but was try to find a document. I teach at a school, and want something to pass along to the class.

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Originally posted by Brian G.

Chris,

My Dad is still in the wholesale electric supply business here, at a place that has Square D everything. I'm sure I can get you copies of the relevent pages in the Sq. D catalog, would that help?

Brian G.

Brian,

I'd love that! I'd be happy to reemburse you for faxing the docs. 623 551 1784

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Got it. Just for the record, the HOM line specs allow 1 #14 - 8 or 2 #14 - 10 (copper) on single pole breakers between 15 - 30 amps. I can't imagine trying to get a #8 under that lug myself, but whatever. Strangely, the double poles from 15 - 30 appear to also allow double-tapping...haven't seen that yet.

Brian G.

Double-Lugging Is What You Do With Twin Babys at a Mall [:-crazy]

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