Thread: neutral terminal

What are the odds that this terminal is rated for two wires? This place was huge, and was wired very pro, but this showed up in one of the 7 panels. It feeds from one panel to the next one beside it. I searched on the web but can't find any single hole lugs that size rated for two wires.


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I can't see the photo.

Originally Posted by Jim Port

I can't see the photo.

Thanks. Not sure what happened there.

I agree with you Jim, one only. This could be confirmed by checking the label in the panel that should show the number and acceptable size range.

Looking at the photo I think it is a tough call to make one way or the other. They do make lugs that are designed for two conductors that look just like that one. The actual lug is marked for the number of conductors and the size , but it it tough to see as it is normally stamped on the part that bolts to the panel. That lug looks deeper than most. The lugs that look like that one and are designed for two conductors will normally have an elongated opening for the two conductors thus making them deeper than the standard. That's just my 2 cents worth

I've spent about 30 minutes on Thomas and Bett's web site, and I can't find one lug that is rated for two conductors that doesn't have two separate holes for the wires. My report isn't due until Monday. I have a call in to my old boss who has been a commercial electrician forever, so I'll see what he says.

Originally Posted by Jim Robinson

I've spent about 30 minutes on Thomas and Bett's web site, and I can't find one lug that is rated for two conductors that doesn't have two separate holes for the wires. My report isn't due until Monday. I have a call in to my old boss who has been a commercial electrician forever, so I'll see what he says.

Do you have a photo showing that terminal lug from a different angle? It is quite possible, due to the apparent height of the lug (or is that an optical illusion?), that the terminal lug is rated for two conductors.

I've seen some which had (as best I can think of describing them): two 'half holes' in the terminal, one above the other, and the terminal lugs were identified as being rated to 2 conductors along with the size of the conductors allowed in the terminal.

That's the only photo I have. It was in a tough spot to get the photo. Any recollections of what brand had one with the two wires allowed? I have looked and looked, and I can't find one. That's a 2/0 and #2 wire I think. I have to look back in my notes.

It is round, not oval of figure eight shaped.

It would also help if you had posted the manufacture and model of Panel that it is in.From what you said in your original post I am curious if it a factory designed feed thru panel?

The panel looks like a SQ D NQOD, do you have a catalog number of the panelboard interior? It may help in deciding if it is OK , if info is avail. online or in a SQ D catalog.

Originally Posted by Jim Robinson

It is round, not oval of figure eight shaped.

Then, most likely, it is only rated for one conductor.

It is a good practice to take a photo of the panel label, especially if you have any questions about it, but taking a photo of the label anyway (questions or no questions) will make it easier to answer questions which may come up later.

I don't see anything in 408.41 (2011 NEC) that restricts the application of the rule of one grounded conductor per terminal to branch circuits in a panel regardless of the listing of the lug. This application would require a lug with 2 separate connections (2 holes, 2 setscrews)

408.41 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.

I should have written down or photographed the data sticker, but I didn't. Good call on the NQOD, I do think that is what the panel is, circa 1998. The only spot where I can see that two wires are allowed are when there is a pass through lug installed. That is not the case here.

I found a PDF for a similar, if not the same, panel. Page 11 shows the pass through lugs, which don't look like this one.

http://static.schneider-electric.us/...1630CT0701.pdf

I'm confident enough to cut that part loose. Now if I could just verify my boiler pump wiring once and for all.

highlighting with bold and underlining are mine:

Originally Posted by Bill Kriegh

I don't see anything in 408.41 (2011 NEC) that restricts the application of the rule of one grounded conductor per terminal to branch circuits in a panel regardless of the listing of the lug. This application would require a lug with 2 separate connections (2 holes, 2 setscrews)

408.41 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.

Could thye be parallel conductors? They look to be the same size.

Does't anyone else think that that lug is NOT original to that equipment?

It does look strange with the mounting bolt appearing to be under the neutral bar. It does look taller than the normal factory lug.

Originally Posted by Jim Port

It does look strange with the mounting bolt appearing to be under the neutral bar. It does look taller than the normal factory lug.

I just pulled a lug off a scrap SQ D interior, and the angle of the photo just makes it look strange, wanted to look at the data on the lug & it was a "standard" single conductor lug made by Ilsco w/ a range of 6 AWG to 300 MCM.

Reason it's scrap is the deadfront is missing.

Not parallel conductors, just tapping over to the next sub panel beside this one. I also think the lug was added to the panel. I'm on safe ground here. If that lug is rated for two conductors of that size, I can't find it in any electrical supply catalog.

Originally Posted by Jim Robinson

Not parallel conductors, just tapping over to the next sub panel beside this one.

Then the exception to allow two grounded (neutral) conductors in one terminal which is identified for two conductors does not apply - meaning it is not allowed (even if the terminal had been designed and listed for two conductors).

Originally Posted by Jim Robinson

What are the odds that this terminal is rated for two wires? This place was huge, and was wired very pro, but this showed up in one of the 7 panels. It feeds from one panel to the next one beside it. I searched on the web but can't find any single hole lugs that size rated for two wires.

Seven panels. Have you considered the possibility that these are serivice conductors and the adjacent panel is not being fed, but supplied as additional service equipment? Where is the bond to the local grounding system taking place (outside - meter can ? or inside)? What sort of raceway between these adjacent panels and how are they bonded? I don't recall you're having said in the discussion that the hot conductors from one panel to the next one beside it" were actually OC protected in the first, just that this panel suposedly "feeds", and I am suspicious of that conclusion without more information and guess that there just may be more than one MCB service panel constituting the "service". Are there multiple metered occupancies present?

If there is an engraved "2" on the lug this would be definitive, as would a notation on the wiring diagram/label for the panel. From the the shadowed poorly lit and staged vantage point of the photo and presuming the same type the grounded (service?) conductors appear to be the same size.

Originally Posted by H.G. Watson, Sr.

Seven panels. Have you considered the possibility that these are serivice conductors and the adjacent panel is not being fed, but supplied as additional service equipment? Where is the bond to the local grounding system taking place (outside - meter can ? or inside)? What sort of raceway between these adjacent panels and how are they bonded? I don't recall you're having said in the discussion that the hot conductors from one panel to the next one beside it" were actually OC protected in the first, just that this panel suposedly "feeds", and I am suspicious of that conclusion without more information and guess that there just may be more than one MCB service panel constituting the "service". Are there multiple metered occupancies present?

If there is an engraved "2" on the lug this would be definitive, as would a notation on the wiring diagram/label for the panel. From the the shadowed poorly lit and staged vantage point of the photo and presuming the same type the grounded (service?) conductors appear to be the same size.

Thanks for joining in a week after the last post and bringing all sorts of extraneous questions to the table. The question certainly seemed easy enough to understand and answer for all the other contributors without all the sidetrack.