Thread: Multiple neutrals under same lug

Does anyone else have a problem when they call out two neutrals under one screw, or a neutral and ground under same screw? In my area local building department and electricians say its OK, or choose to ignore it. Now the owner of the real estate company where I get most of my work thinks I dont know so much.....

Similar Threads:

• multiple NM cables entering panel enclosure through one fitting
• condo - grounds / neutrals
• Multiple vents through one opening
• Grounds and Neutrals
• Multiple siding layers

2 neutrals under a single lug not a problem.

Grounds and neutrals should be separate.

Upset realtor: Who gives a *#!& ?

I write up multiple neutrals, or neutrals mixed with grounding wires, under same lug all the time - nearly every inspection. Never had a complaint.
According to the IRC and NEC and most manufacturers, it is a problem.

I always call out multiple neutrals terminating to the same lug on the buss bar. Never had a a problem with electricians, many have commented to the positive however. But, to each geographical location its own I guess.

Paul If I was you I would print out the NEC pertaining to this issue and show them you are correct. Just because Electrician does it does not make it correct. Hopefully Jerry will post the NEC for this so you have the Ammo.
If you do a search I am sure you can find it.

2006 IRC E3606.4 Grounded conductor terminations. Each grounded conductor shall terminate within the panelboard on an individual terminal that is not also used for another conductor, except... yada yada about parallel conductors where the terminal is identified for more than one...
2002 NEC 408.21 Same wording.

Originally Posted by Rick Hurst

2 neutrals under a single lug not a problem.

Yes, that IS a problem.

Grounds and neutrals should be separate.

True, but NEUTRALS should ALSO be separate.

As should two hot conductors.

From the NEC.
- 408.21 Grounded Conductor Terminations.
- - Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.
- - - Exception: Grounded conductors of circuits with parallel conductors shall be permitted to terminate in a single terminal if the terminal is identified for connection of more than one conductor.

But that Exception gets into what was posted on another thread - the smallest conductors allowed to be paralleled are 1/0. So, that Exception does not apply to your standard panelboard with neutral terminals sized 14-1 (although none probably are sized beyond 14-8 for the typical terminal, not counting the main neutral line terminal, which is still only rated for one conductor, so the Exception would not apply to it either.

Jerry not to question you, but I did an inspection in a newer home last week. The buyer was a older gentleman who owned a large electrical business and is an longtime electrician himself. As we looked at the distribution panel, there were some neutral wires that were doubled up under one lug. I stated this is not allowed and he agreed, and then said but if the panel states it is rated for this, it is OK. We read the fine print on the panel and sure enough it did state that two wires could terminate under one lug. Now the question is, is this still wrong even though the manufacture states it is OK?

if the grounded conductors of two branch circuits were terminated at a single connection point and it was necessary to isolate one branch circuit for the purposes of troubleshooting, the fact that the circuit not being tested remains energized can create an unsafe working condition for service personnel disconnecting the grounded conductor of the circuit that is being tested.

See 408.20 for the requirements on panelboard terminations for grounded and equipment grounding conductors-- some panelboard instructions allow a single termination point for more than one conductor, ONLY IF SPECIFIED. Otherwise, this is prohibited by the NEC.

Richard

Richard I understand that it is allowed "only if specified". But, if I am reading Jerrys comments correctly, he is saying it is only allowed if the conductor is equal or larger than 1/0. Am I missing something here?

Originally Posted by Todd Erickson

and then said but if the panel states it is rated for this, it is OK. We read the fine print on the panel and sure enough it did state that two wires could terminate under one lug. Now the question is, is this still wrong even though the manufacture states it is OK?

Nope not allowed, regardless, not for those size conductors.

What you read, I am assuming - because it is in most panels, is that two GROUNDING or *equipment ground* conductors are allowed.

NOT two "neutrals" or "groundED conductors".

Only when you get to paralleled conductors, which must be 1/0 and larger, is that allowed, and only then *if the terminal is identified* for more than one conductor.

Here's part of a label from a Siemens panel. To the right of where it says "Neutral/Ground Bars" it shows the size of cu and al wires acceptable. Under that, where it says Ground Conductors Only, it then shows that 2 or 3 conductors of the sizes shown can be used, but those are equipment grounds, not "neutrals".

I guess this is wrong huh

You mean because of all the equipment grounds bunched at the big terminal at the top and/or the single equipment ground at the big terminal at the bottom?

I provide this PDF Document to my clients when discussing this issue.

Originally Posted by Mike Huppi

I guess this is wrong huh

Mike, It's not perfectly clear in your photo... but, it looks like the top grounded conductor is not in the same set-screw as the grounding(ground) counductors-- which would make that set up ok.

The grounding (ground) conductors CAN have multiple conductors under teh same set screw but there should-not be grounded conductors (think neutrals) with multi-conductors under the same set-screw. Nor should there be both a grounding and grounded conductor under the same set screw at that bar.

Clear as mud??

Originally Posted by Richard Rushing

The grounding (ground) conductors CAN have multiple conductors under the same set screw

Whoaaaaa there Nelly.

"Multiple conductors"?

Okay, yes, as in "2" and a few panels may even allow "3", BUT ...

THAT SHOWS many more than 2 or 3, and THAT is not allowed.

I wrote it up for an electrician. All of the grounds on this entire home were under 3 lugs. I do not think that is correct or safe.

I hope this is an appropriate thread for this question.....

I'm having a brain-fart when it comes to aluminum branch wiring. In the panel(s), what am I looking for? How is the presence of aluminum branch wiring or branch circuits identified? I'm new at this and just tryin' to learn !

Originally Posted by Bob Stark

I hope this is an appropriate thread for this question.....

I'm having a brain-fart when it comes to aluminum branch wiring. In the panel(s), what am I looking for? How is the presence of aluminum branch wiring or branch circuits identified? I'm new at this and just tryin' to learn !

Hi Bob, we are all learning!

It would have been best to start a new thread, for future reference.

The best way is to take a look inside the panel and at the outlets. Also the time that the house was built is always a red flag. Mid 1960's to the late 1970's tends to be the most common time frame.

Bob,

Take a look here:

The Aluminum Wiring Information Website - How to Identify and Repair Aluminum Wiring in Buildings, COPALUM connectors, Aluminum Wire connectors,Aluminum Wire Pigtailing Repairs, COPALUM Certified Electricians Directory, TYCO, AMP, Copper Pigtailing,I

Thanks Scott! And thanks for the "new thread" tip.
Micheal, that's quite a website! Very useful. Thanks !

I posted this on another thread, but don't have time to look for where. This article may help to understand why all the above groupings are a bad idea.

Hello to all,

What does "...or for all combinations of up to three #10 solid wires." in this label mean? 2 neutrals and a ground, 2 grounds and a neutral, 3 neutrals, 3 grounds? If no, then what does "combinations" mean?

Thanks.

Originally Posted by Shane Pouch

Hello to all,

What does "...or for all combinations of up to three #10 solid wires." in this label mean? 2 neutrals and a ground, 2 grounds and a neutral, 3 neutrals, 3 grounds? If no, then what does "combinations" mean?

Thanks.

It means combinations of grounds, the combinations part refers to the conductors, combinations of size and material, not combinations of their functions.

To help clarify what Bob said ...

That is referring to what we have been saying - "groundING" conductors, as in "equipment groundING" (green or bare) conductors.

For groundED (neutral) conductors - no, that is not allowed.

Bob, Jerry, Thanks.

So, for example, it's okay to have, say, a #14 & #10 equipment ground under the same lug? That doesn't make sense, as the smaller conductor won't be clamped as much by the lug screw.

Some panel labels read something to the effect that multiple wires are okay, but only if the same size. Why do some panels read this way, while the past few comments indicate different sizes are okay? Just a little confused here.

Originally Posted by Shane Pouch

So, for example, it's okay to have, say, a #14 & #10 equipment ground under the same lug? That doesn't make sense, as the smaller conductor won't be clamped as much by the lug screw.

That is what it says, weird though.

Some panel labels read something to the effect that multiple wires are okay, but only if the same size. Why do some panels read this way, while the past few comments indicate different sizes are okay? Just a little confused here.

I have no idea, guess you would need to ask them (the manufacturers) why they tested it the way they did.