Reuben's Home Inspection Blog

How To Correct Double Tapped Circuit Breakers

By In Double Tapped Circuit Breakers On January 19, 2010


Double tapped circuit breakers are one of the most common electrical defects that I find while doing home inspections in Minneapolis and Saint Paul, and they’re usually one of the easiest defects to correct.  Today I’ll explain what double tapping is, when it is and isn’t a problem, why it’s a problem, and how to correct this condition.

I didn’t consult with an attorney before writing this article, so I feel like I should add a disclaimer before giving any electrical how-to information:  Don’t do any of this work if you’re not qualified.  You could get electrocuted or start a fire.  This is only an overview.

Definition: When I say ‘double tap’, I’m actually not using the correct terminology; this is just what a lot of home inspectors say when two conductors are connected under one screw or terminal inside a panelboard.  There is no official term for this, so double tap works for me.  Sometimes this refers to two conductors at one circuit breaker, other times it refers to two conductors connected under one screw at the neutral bar.  Today I’ll be discussing two conductors connected to a single circuit breaker.

When it’s NOT a defect: Double tapped wiring is ok if the circuit breaker is designed for two conductors.  If a circuit breaker is designed for two conductors, it will say so right on the circuit breaker, and the terminal of the circuit breaker will be designed to hold two conductors in place.  The circuit breaker shown below is an older Square D designed to accept two conductors.  I highlighted and enlarged the portion of the label that says two conductors can be attached.  This is acceptable.  The only manufacturers  that make circuit breakers that are designed to hold two conductors are Square D and Cutler Hammer… but not all of their circuit breakers can be double tapped.

Square D Breaker

Here’s a newer type of Square D circuit breaker – instead of putting a bunch of text on the front of the circuit breaker, they now just have a little picture on the front of the breaker.

Square D Homeline

They now put the text on the side of the breaker.

Text on side of Square D Homeline circuit breaker

When it IS a defect: This is a defect when the circuit breaker isn’t designed for two conductors; most aren’t.  It doesn’t matter if it’s just a simple doorbell transformer wire that’s added on to the circuit breaker – the issue isn’t about the load imposed on the circuit, it’s about the physical connection.

Double TapSingle Pole Label

Why it’s a problem: If the circuit breaker isn’t designed to hold two conductors, the conductors could come loose at some point in the future, even if they feel very tight today.  Loose conductors can lead to overheating, arcing, and possibly a fire.

How to fix: The fixes I’m going to list below are a few common ways of dealing with double tapped circuit breakers.

Pig Tail:  This is the most common repair, and it’s ridiculously simple.  The offending conductors simply get disconnected from the circuit breaker, connected to a single conductor with a wire nut, and that single conductor gets connected to the circuit breaker.   Now, I know what you’re thinking: “What’s so tough about that?”  The answer is nothing.  This is a quick and easy fix.

 

Pig Tail

Different Circuit Breaker Another simple repair would be to replace the circuit breaker with a type that is designed for two conductors, as long as the panel is designed for it.  This would be more involved than the pig tail repair, and I don’t know why anyone would want to do this, but it would certainly be acceptable.

If there are more problems going on besides just a double tap, the repair might get more involved.  For instance, if a homeowner finished off a basement and added a circuit for the basement bedroom on to the circuit breaker for the bathroom receptacles, simply adding a pig tail for the wires wouldn’t be a proper repair, in part because the bathroom receptacles can’t be on a shared circuit (and the bedroom circuit needs AFCI protection – more on that another day).   In this case, the conductors would need to be split off on to two separate circuit breakers.  There are a few ways to do this.

Add A Circuit Breaker If there is room in the panel, another circuit breaker can be added, and the conductors split off to the two different circuit breakers.

Two Circuit Breakers

Install A Tandem Breaker If the panelboard is designed to use tandem breakers and a tandem breaker can be properly used in lieu of the offending circuit breaker, this is another acceptable fix.  This is basically a way to install two circuit breakers in one space.

Tandem Breaker

 

If a panel will accept tandem breakers, it will say so inside the panel, and the specific locations where tandem breakers can be used will be identified.  A panel may allow all tandem breakers, no tandem breakers, or some tandem breakers.  The photo below shows a panel that allows some.  As you can see, eight more circuits could be added to this panel, as there are currently no tandem breakers being used.  This would take some shuffling around, but it wouldn’t be a big deal to do.

Tandem Breakers Label

When none of the above solutions are possible, the repair might involve replacement of the panel with a larger one, or the addition of a subpanel.  This would obviously get much more expensive.

 

Reuben Saltzman, Structure Tech Home Inspections – Email – Minneapolis Home Inspector

 

        



About the Author

Reuben

Reuben is a second generation home inspector with a passion for his work. He grew up remodeling homes and learning about carpentry since he was old enough to hold a hammer. Reuben has worked for Structure Tech since it was purchased by Neil in 1997, and is now co-owner of the company. Reuben’s favorite customers are the ones who have a lot of questions; he grew up thinking he was going to be a school teacher because he enjoyed teaching others so much. In a sense, that’s a lot of what home inspections are about, so Reuben truly does what he loves. Reuben has an A.A. degree in liberal arts and has attended most of the Building Inspection Technology classes at North Hennepin Community College. Reuben and his wife are the proud parents of two young childen, Cy Alexander and Lucy Nicole, and have a German Shepherd named Stanley. With two young children Reuben doesn’t have much free time, but he still tries to play disc golf as often as possible during the summer. Reuben lives in Maple Grove, MN. Professional Qualifications / Memberships: *ASHI Certified Inspector *President, ASHI Heartland Chapter *Member, Minnesota Society of Housing Inspectors (MSHI) *Licensed Minneapolis Truth-in-Sale of Housing Evaluator *Licensed Saint Paul Truth-in-Sale of Housing Evaluator *Licensed Maplewood Truth-in-Sale of Housing Evaluator *Licensed Hopkins Truth-in-Housing Evaluator *Licensed Robbinsdale Point of Sale Evaluator *Affiliate Member, Southern Twin Cities Association of Realtors

15 Comments

  • Evon Los 10 MONTHS AGO

    Hi. Did not see a mention in your post that double tapping can also increase the amount of outlets on the circuit to which code only allows 12-14 depending on your local in northamerica. Lets say the first circuit wire had 10 outlets then one with 7 is added for an addition. There are now to many outlets on that circuit.

    • Reuben Saltzman 10 MONTHS AGO

      @Evon - that's correct. I didn't mention anything about the number of outlets for two reasons: 1. There is no limit to the number of outlets on a circuit. There was a limit of 12 outlets per circuit over 80 years ago, but that limit went away in 1933, provided there was one 15 amp circuit for each 500 sf of dwelling. Today, the minimum requirement is one 15 amp circuit for each 600 sf of dwelling. 2. Even if there was a limit to the number of outlets on a circuit, it wouldn't have anything to do with double tapping. The maximum number of outlets could be exceeded without double tapping a circuit breaker, and a circuit breaker could be double tapped without exceeding the maximum number of outlets. The two aren't related.

  • Michael Leavitt 1 YEAR AGO

    Reuben, I like your double tap explanation, but I feel that you did not deal with another primary reason that our home inspection industry identifies all of the double tapping and recommend immediate evaluation and repair by licensed electricians. Yes there is the fire safety and overheating issue from the poor connections, but the other key point is that the added work was done by somebody lacking electrical experience. Here in Utah we have 95% basements with the majority being finished by well-intentioned homeowners and wannabe electricians after the original build. The double tap is the “Red Flag” that alerts us of unsafe workmanship, and we routinely recommend that a licensed electrician repair the double tap and evaluate the affected circuits. It also shows that the work was NOT completed with the benefit of building permits, which is required by law in our area when circuits are added. The bigger issue is not the ease with which double taps are repaired, but the lack of confidence conveyed by the sub-standard and unsafe workmanship. Keep up the good articles! Michael Leavitt - Orem, Utah - ElectricalFire.info

  • Peter Notarfrancesco 1 YEAR AGO

    Not all installers are competant. I had Sears install a 3.5 ton AC in my house. When I inspected the job they had double tapped breakers to make room for the 208 volt breaker. I bitched at them and they told me that was a common practice. I asked them:" Is it Code?" They double talked but never answered. So I asked the question again but louder and they replied that their source did not have the tandem breakers for my box. I told them where to get them and they obtained the correct breakers. All is now code.

  • Sean Sumter 1 YEAR AGO

    My incoming HDTV lines are just under my electrical panel. Due to weak signals, cable company wants to add a powered amplifier. Was researching a method to add electrical outlet to panel to feed a 12v power source for amplifier when I found your site. Perfect for what I need. Thanks for the effort you put into it!

  • Reuben Saltzman 1 YEAR AGO

    Hi Julia, that might be a good question for an attorney that specializes in real estate matters... however, correcting double tapped circuit breakers is usually a very quick and easy fix for an electrician. I would contact the electrician who did the original work; they're the ones who are ultimately responsible for doing it right the first time. If they made a mistake, maybe they'll stand behind their work and fix it for free.

  • Julia Gamble 1 YEAR AGO

    We bought a home in 2005-new construction. It passed the town inspection & a separate home inspection. We go to sell it 2013 & the buyer's inspector notes "double taps" in the report. We have a Siemens electrical panel. Some of the lower circuits allow for tandem wires as shown by the schematic on the panel door, but that's not where the doubling occurs. Do I have an recourse with the home inspection company that we hired in 2005, the town inspector, or with the original electrician?

  • Tim Hegadorn 1 YEAR AGO

    This is a very well written and illustrated article. Great job!

  • Po 1 YEAR AGO

    Thank you for a very easy to follow and thorough explanation.

  • Glen Copealnd 3 YEARS AGO

    I like your explanation of double tap wiring and the photos. Thinking about adding more photos to my site http://www.electricianpdq.com/electrical-problems/request-to-remedy.php

  • Kevin G 4 YEARS AGO

    Reuben, I had been reveiwing the home inspection report on a property we are considering buying and I was in the dark about double taps and how they can be corrected, your expalantions and the photos were a huge help Many Thanks Kevin

  • David Meek 5 YEARS AGO

    Thank you for your detailed explanation here, Reuben. I am an Indianapolis real estate agent and have seen double taps on home inspections for over a decade but wasn't sure what the right fixes were. Good photos! Thanks, David

    • Reuben Saltzman 5 YEARS AGO

      Hi David - I don't think you're alone. Most people assume that another breaker always needs to be added.