Reuben's Home Inspection Blog

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Double Tapped Neutrals: This Isn't A New Rule

While I try to make most of my blog posts somewhat generic and appealing to most, this one ain't that.  This post is about a very specific electrical defect that I frequently run across, and I'm writing this post so I can give my clients a better explanantion of this defect.  Oh, and also so I can give my clients proof that this isn't some new requirement that I just heard about.

Double Tapped NeutralThe problem I'm addressing today is double tapped neutral lugs in electric panels.  A 'double tapped neutral' is another way of 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 very 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 theSchneider-Electric web site.  The other reason you can't have two neutral wires connected under a single lug is because the connections might come loose.  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.   Oh, and for the record, if a home inspector recommends a repair of say, a double tapped neutral, they're doing it for the reasons listed above; not because it's "code".

Reuben Saltzman, Structure Tech Home Inspections

        

Comment balloon 18 commentsReuben Saltzman • May 24 2011 06:05AM

Comments

Had one just yesterday!  See them all the time!  And the County seems to brush over it as well...

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

Good morning, Ruben. I see this frequently too. The municipal inspectors seem to let this slide as well. As long as the wiring size is the same, I don't say anything. It is what it is...

Posted by TeamCHI - Complete Home Inspections, Inc., Home Inspectons - Nashville, TN area - 615.661.029 (Complete Home Inspections, Inc.) over 7 years ago

Jay - the county inspectors don't care, even to this day?  Even though it's spelled out in the code?  Even though it's prohibited by panel manufacturers?

Michael - what about double tapped circuit breakers?

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

Ruben great information and should give cause for us to at least take a look in the panel box

Posted by Myers Jackson, America's Auctioneer (Auctioneer, Texas Flip N Move ) over 7 years ago


They just seem to miss it.  I see it all the time.  Could be they never go into the box...  hmmm... go figure.

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

Myers - every time :)

Jay - Hmm... you're probably right.  My dad had a new panel installed at his house about a year ago, and the inspector never even looked inside.  Hey, what happened to your eye?  I suppose I better check your blog.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

Check it Reubs, but between you and me, don't believe a word of it...   shhh!    ;>)

Actually I was really, really lucky.  It was close enough that I would never have laughed again at that line in the Christmas movie, "You'll put your eye out kid!"

Posted by Jay Markanich, Home Inspector - servicing all Northern Virginia (Jay Markanich Real Estate Inspections, LLC) over 7 years ago

We work in somany different jurisdictions there is no point in citing codes and regs. We just advise about unsafe, at risk. or potential expense conditions. And that pretty much covers everything.

Posted by Robert Butler, Montreal Home Inspector | Aspect Inspection (Aspect Inspection) over 7 years ago

Reuben, I see this all the time and I call it out all the time.  The most I have seen under one screw is 7 and they were all aluminum :)  The other thing I always mention is that this is a supper easy thing for the electrician to fix.

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) over 7 years ago

Ruben,

 I see this way too often also. Got a better one yesterday triple tap main lug. Got to love that one. No problems there, right, they all black; )

Posted by Donald Hester, NCW Home Inspections, LLC (NCW Home Inspections, LLC) over 7 years ago

Jay - I love that line!  I don't know how it happens, but I'm pretty sure I watch some of that movie every year.  

Robert - whenever I hear about someone talking about all the different codes and jurisdictions they need to keep track of, I'm grateful to be inspecting here in Minnesota, where the codes are truly uniform.  They might not be enforced uniformly, but they're supposed to be.

Charles - SEVEN?  I don't think I've even seen that many grounds under a single screw.  It's super easy to fix if there are extra lugs to use :).  What prompted this post was a voicemail from an electrician telling me he wasn't going to fix the doubled neutrals because it wasn't code when the panel was installed, and I can't make someone fix something that was installed to code.   Gee, thanks for telling me how I'm allowed to do my job, dillweed.  

I called the electrician, and the real reason he didn't fix the doubled neutrals was because there wasn't any more room for neutrals, he wasn't aware of UL 67, and he didn't have any extra neutral bus bars with him when he was at the property.

Donald - it didn't happen to be an old fuse panel, did it?

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

Interesting link to Jim Pauley's article.  It sounds to me like he is referecing a dangerous work practice, working on a live panel and only de-energizing a single branch circuit.   No doubt a risky and dangerous work practice with a single or double tapped neutral bus.

I do not recommend working on a live panel, even if the neutral bus has only single tapped connections.

In my experience, wire connections loosen due to several factors that induce movement.  The changes in heat, or use of the circuits will vary the expansion/contraction characteristics of the conductors and connectors.  Single tapped neutral bus connections are not immune to loosening.

Another one of your well written articles with a reference to a credible source.  I am not in agreement with Jim Pauley on this one.

 

Posted by Jim Mushinsky (Centsable Inspection) over 7 years ago

Reuben, I guess my memory isn't what it used to be :)  The 7 neutrals were copper.  The 7 aluminum were grounds.

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) over 7 years ago

Jim - thanks!  But as far as working on a live panel... you've never done it yourself, even at your own house?

Charles - yeah but still.  Yeah but still.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 7 years ago

I call this out all the time as well. It is probably more common that double lugged breakers.

Posted by James Quarello, Connecticut Home Inspector (JRV Home Inspection Services, LLC) over 7 years ago

Reuben, thanks for the pictures and explanation.  I did not know what that was or why it wasn't OK.  Now I do!

But hey, that's why I don't do anything with electrical work.  :)

Posted by Jeremy Wrenn, President, Wrenn Home Improvements (Wrenn Home Improvements) over 7 years ago

This is a great post and the sort of thing I love to share with my buyer clients.  Thanks for the information.

Posted by Gene Riemenschneider, Turning Houses into Homes (Home Point Real Estate) over 7 years ago

From what I can tell from the comments, is that double lugging is not a hazard for the standard operation of the home.  It is a hazard when working on / troubleshooting / modifying the box.  Is this true?  If not why?

Posted by MVen over 6 years ago

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