# adding #4 lug to neutral buss



## crazymurph (Aug 19, 2009)

You can buy a lug that fits into 2 spaces on the neutral bar.


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## wildleg (Apr 12, 2009)

http://ecatalog.squared.com/pubs/Electrical%20Distribution/Load%20Centers/QO%20Three%20Phase%20Load%20Centers/1100CT0501.pdf

page 16


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## McClary’s Electrical (Feb 21, 2009)

A#4 will fit in a homeline buss.


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## McClary’s Electrical (Feb 21, 2009)

billyrr said:


> Using a Sq D Homeline panel I need to attach a #4 to the neutral buss or to the panel can. That buss won't accept a #4. We don't usually use Homeline panels so we're less familiar with them.
> 
> The primary ground lug is taken.
> 
> I know we can add a mechanical lug to the panel can with a self tapping screw, however this #4 is required between the two panels as it is a 400a service with 2) 200a panels, so I'm not sure where to terminate.


 

There is nothing that requires anything between the two panels on a 400 amp service.


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## sbrn33 (Mar 15, 2007)

mcclary's electrical said:


> There is nothing that requires anything between the two panels on a 400 amp service.


Especially a #4


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## electricmanscott (Feb 11, 2010)

mcclary's electrical said:


> A#4 will fit in a homeline buss.


It's tight but it fits.


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## McClary’s Electrical (Feb 21, 2009)

electricmanscott said:


> It's tight but it fits.


 

That's what _she_ said.


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## Dennis Alwon (May 9, 2009)

mcclary's electrical said:


> There is nothing that requires anything between the two panels on a 400 amp service.





sbrn33 said:


> Especially a #4



I think the OP may have run a 1/0 or a #2 GEC to one panel. In this case a #4 is required between the panels.


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## McClary’s Electrical (Feb 21, 2009)

Dennis Alwon said:


> I think the OP may have run a 1/0 or a #2 GEC to one panel. In this case a #4 is required between the panels.


 
That wouldn't be legal because if he ran a #2 to the first panel, then that would mean the GEC from panel #2 would not be continuous to the first electrode.


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## Dennis Alwon (May 9, 2009)

Look at this


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## McClary’s Electrical (Feb 21, 2009)

Dennis Alwon said:


> Look at this


 
That's a different setup than you described. You said run to the first panel with a jumper between them. The connection would need to be continuous, or irreversible crimp.


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## Dennis Alwon (May 9, 2009)

mcclary's electrical said:


> That's a different setup than you described. You said run to the first panel with a jumper between them. *The connection would need to be continuous, or irreversible crimp*.


Okay, you are correct in that there is nothing required between the panels but I was trying to show that if a #2 went to one panel then a #4 could be taken off the GEC in panel #1 to panel #2. This can be done with irreversible crimps or with a listed connector for grounding. I might even state that the bus bar in the panel is a listed connector for grounding and bonding. As long as the #2 is continuous that is all that is necessary. The other is a bonding jumper. I think. At least i get this from 250.62(D)(1)


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## tkb (Jan 21, 2009)

billyrr said:


> Using a Sq D Homeline panel I need to attach a #4 to the neutral buss or to the panel can. That buss won't accept a #4. We don't usually use Homeline panels so we're less familiar with them.
> 
> The primary ground lug is taken.
> 
> I know we can add a mechanical lug to the panel can with a self tapping screw, however this #4 is required between the two panels as it is a 400a service with 2) 200a panels, so I'm not sure where to terminate.


What do you mean by a self tapping screw?


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## Shockdoc (Mar 4, 2010)

Our AHJ has us run the #1 to first panel and bugnut off of it outside panel with #4 to second panel.


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## McClary’s Electrical (Feb 21, 2009)

Dennis Alwon said:


> Okay, you are correct in that there is nothing required between the panels but I was trying to show that if a #2 went to one panel then a #4 could be taken off the GEC in panel #1 to panel #2. This can be done with irreversible crimps or with a listed connector for grounding. I might even state that the bus bar in the panel is a listed connector for grounding and bonding. As long as the #2 is continuous that is all that is necessary. The other is a bonding jumper. I think. At least i get this from 250.62(D)(1)


 
That's interesting and I've never seen that done. The wording in 250.64 (d) (1) says the tap conductors shall be connected by exothermic weld or with connectors listed as grounding and bonding equipment. So the question is, Are ground lugs called connectors? 250.64 (b) (1) demand irreversible crimp or connectors listed for grounding and bonding also. I find it hard to believe you could take a ground buss, stick a wire in both ends, tighten two screws, and meet the intent of the code. Now, picture that grounding buss inside your first panel, stick two GEC's in it, tighten two screws? Not too sure that's the intent.


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## troublemaker1701 (Aug 11, 2011)

*..........*


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## Dennis Alwon (May 9, 2009)

Shockdoc said:


> Our AHJ has us run the #1 to first panel and bugnut off of it outside panel with #4 to second panel.


That is compliant IMO. But it can be done inside the panel also. We just go to the meterbase and we're done.


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## macmikeman (Jan 23, 2007)

Slightly on topic and slightly off topic, but seems to me the people who make panels and meter sockets and so forth seem to be unaware of the fact that using SER cable in many cases, has resulted in running larger cables than what has been allowed to run in past issues of the code. (or at least things were not defined as they are now...)

I used to be able to run #2 AL ser cable for a 100 amp sub panel, usually one of two serving the dwelling, if the incoming service was 200 amps. Now, since the 2008 NEC, I run 1/0 for the same sub panel feeders. The equipment ground conductor in a 1/0 al ser cable is #2. The grounding bus bars on a lot of the factory supplied in the panel grounding bars accepts up to #4 conductors. Ok, I know how to remove and replace a grounding bus with one that has a built in lug that takes larger wires, but it is a bit of a hassle to always stock enough of them on the van given all the panels I end up installing or exchanging in a given period of time. Changing the busbar is still way cheaper a way to go than changing the sub feed to pipe and wire, or to a copper based NM cable, so don't even bother to suggest that as a cure to me....... By the way, the loading on any of those sub feeders never seem to go over 40 amps anyway once I hook everything up............
This is why I get pretty pissed off when I hear about clowns who insist on submitting 20 or so code change proposals every three years. The game they play which is "Look at me, I got 5 passed this time around, aren't I such a great electrician....." Very seldom is any real... and I mean real... safety is added from all this fun and games. Rant over....


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## electricmanscott (Feb 11, 2010)

macmikeman said:


> Slightly on topic and slightly off topic, but seems to me the people who make panels and meter sockets and so forth seem to be unaware of the fact that using SER cable in many cases, has resulted in running larger cables than what has been allowed to run in past issues of the code. (or at least things were not defined as they are now...)
> 
> I used to be able to run #2 AL ser cable for a 100 amp sub panel, usually one of two serving the dwelling, if the incoming service was 200 amps. Now, since the 2008 NEC, I run 1/0 for the same sub panel feeders. The equipment ground conductor in a 1/0 al ser cable is #2. The grounding bus bars on a lot of the factory supplied in the panel grounding bars accepts up to #4 conductors. Ok, I know how to remove and replace a grounding bus with one that has a built in lug that takes larger wires, but it is a bit of a hassle to always stock enough of them on the van given all the panels I end up installing or exchanging in a given period of time. Changing the busbar is still way cheaper a way to go than changing the sub feed to pipe and wire, or to a copper based NM cable, so don't even bother to suggest that as a cure to me....... By the way, the loading on any of those sub feeders never seem to go over 40 amps anyway once I hook everything up............
> This is why I get pretty pissed off when I hear about clowns who insist on submitting 20 or so code change proposals every three years. The game they play which is "Look at me, I got 5 passed this time around, aren't I such a great electrician....." Very seldom is any real... and I mean real... safety is added from all this fun and games. Rant over....


Agreed and some of these guys are right here on this site. :whistling2:

As far as the panel goes run the #2 and use a smaller breaker.


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## Dennis Alwon (May 9, 2009)

macmikeman said:


> This is why I get pretty pissed off when I hear about clowns who insist on submitting 20 or so code change proposals every three years. The game they play which is "Look at me, I got 5 passed this time around, aren't I such a great electrician....." Very seldom is any real... and I mean real... safety is added from all this fun and games. Rant over....


Guilty as charged except that I don't do it for the fame. It is a rare individual that will get 1 passed let alone 5.

Also some of the proposals are made, at least the ones I made, to clarify what was written. Many changes are just rewording or adding a little bit and nothing more. Overall we have a pretty good document although it can be difficult to decipher.


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## 3xdad (Jan 25, 2011)

FWIW. It's interesting that if the sole electrode is only 2 rods, you can run a #6. i would be curious as to what electrode the OP has.


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## billyrr (Oct 31, 2011)

*#4 lug Orig Poster following up*

Sorry I could not respond earlier, but my Comcast was out.

Ok, a few posters wanted to know the OP's exact situation so here we go.

We have 2) 200 amp panels each fed by a separate 4/0 SEU cable.

The first panel is grounded to driven grounds and to the cwp.

The inspector tells me that he requires a #4 bonding jumper between the 2 panels.

So that is what the OP is all about.:blink:


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## Dennis Alwon (May 9, 2009)

billyrr said:


> We have 2) 200 amp panels each fed by a separate 4/0 SEU cable.{/quote] That , IMO may be a violation depending on what cycle the install in under.
> 
> 
> 
> ...


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## billyrr (Oct 31, 2011)

curious what about this service setup might be in violation?

you see it everywhere!


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## Dennis Alwon (May 9, 2009)

billyrr said:


> curious what about this service setup seems to be in violation?
> 
> you see it everywhere!


There are a few arguments. First is that T310.15(B)(6) states that the service conductors must carry the entire load of the dwelling. How can one set of 4/0 carry the entire load. There are two sets so the table is not usable. Now you must use T. 310.16. If the calculated load is 180 or less in both panels then 4/0 seu may be used. If there were an exterior disconnect and these se cables where feeders then you would be limited to 60C. under the 2008.

In reality I doubt you will ever see a problem with it but we are quoting code so....


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## billyrr (Oct 31, 2011)

Dennis Alwon said:


> .... Now you must use T. 310.16. If the calculated load is 180 or less in both panels then 4/0 seu may be used. ......In reality I doubt you will ever see a problem with it but we are quoting code so....


So in large single family residential applications where you can easily have a calculated load over 180a, is it fair to say that it could be a rare instance of inspectors not enforcing a requirement because as a practical matter, those two cables together will easily handle more than 300a?


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## Dennis Alwon (May 9, 2009)

billyrr said:


> So in large single family residential applications where you can easily have a calculated load over 180a, is it fair to say that it could be a rare instance of inspectors not enforcing a requirement because as a practical matter, those two cables together will easily handle more than 300a?



Each cable is only good for 180 amps but because of other factors 4/0 is allowed to be used for a 200 amp service with a calculated load of 200 amps. This is because of the diversity of loads in a home. 

Now when you split the loads to 2 - 200 amp panels someone may load one panel with all the heating/ heat pumps, etc and be over 180 amps. I don't the wire will ever fail as there is safety built into the numbers- I suppose, however it would not be compliant if the load exceeded 180 amps on that panel. 

I agree most 400 amp services will probably never see 300 amps. I believe many inspectors that are aware of this issue may let it go but others may not. I say this because if you work in an area that will not allow it it can be costly.

Had a friend that got nailed on this. He had 2- 200 amp 4/0 ser feeders about 100 feet and not really replaceable so he just took out the 200 amp breakers and installed 150 amp breaker in the panel. In this case they were feeders from ext. meter combo- 400 amps.


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