Reuben's Home Inspection Blog

Double Tapped Neutrals: This Isn’t A New Rule

By In Double tapped neutrals On May 24, 2011


Double Tapped NeutralThe problem I’m addressing today is double tapped neutral lugs in electric panels.  A ‘double tapped neutral’ is a slang term for saying that one of the screws on the neutral bus bar in the panelboard has more than one neutral wire feeding to it.  This is a no-no, and has been for a long time.

One reason that two neutral wires can’t be connected to a single terminal in a panelboard is so that the circuit can be isolated if it needs to be worked on.  There is a great explanation of this at the Schneider-Electric web site.

The other reason two neutral wires can’t be connected under a single lug is because the connections might come loose, which could lead to a fire.  The images below show an overheated conductor at a double-tapped neutral lug.  The left image shows the original photo, and the right image has a thermographic overlay from an infrared camera.

Overheated Neutral

While panel manufacturers will allow for up to three grounding conductors under a single lug, they typically only allow one neutral wire.  The grounding conductors aren’t going to normally carry current for extended periods of time, so they have a very slim possibility of coming loose.  This isn’t the case with the neutral conductors.

Despite what many seem to think, this didn’t become a new requirement in 2002.  This has been a requirement of UL 67 for a long time, but was spelled out in the NEC in 2002.

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

8 Comments

  • Woody 3 YEARS AGO

    1) Since you cannot work on that panel 'live' the isolation arguement is moot. 2) UL 67 does not apply since those are not neutrals. They are grounded conductors. 3) That makes it a code violation. A safety hazard? Very,very,very remote possiblitity.

    • Reuben Saltzman 3 YEARS AGO

      Hi there, Mike. You're going by "Woody" now? I'd say it's good to hear from you... but, well, you know. 1) Since you cannot work on that panel ‘live’ the isolation arguement is moot. I've heard this tired old argument from you before. In the real world, electricians work on live panels all the time. 2) UL 67 does not apply since those are not neutrals. They are grounded conductors. I'm sure you're already aware of the change in the 2008 NEC to define the term neutral conductor. http://www.iaei.org/magazine/2006/07/analysis-of-changes-part-1-nec-2008/ . You can't seriously believe that UL 67 doesn't apply to neutral conductors. 3) That makes it a code violation. A safety hazard? Very,very,very remote possiblitity. Well, I guess I should be glad that's you'll admit it's a possibility. I have to assume you're digging your heels in on this one because of that blog post you wrote on ActiveRain about two years ago, and long discussion that followed it. http://activerain.com/blogsview/1225687/bad-home-inspection-info-electrical . Yes, yes, I know that most of that discussion was about grounded and grounding conductors being connected under the same terminal, but I also called you arrogant and said you have a chip on your shoulder. I don't think anything has changed.

  • James 3 YEARS AGO

    Isn't double tapped hot into the circuit breaker a no-no too?

  • Melinda 3 YEARS AGO

    Not that this has anything to do with your blog, but there is an article on the MSN about the importance of hiring a home inspector when you purchase a home. Made me very grateful that we hired you. Although you didn't find any major stuff, it was just nice to know what we were walking into and what would have to be fixed down the road. It was totally worth the money.