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installing new dedicated circuit - neutral bus full

8K views 12 replies 10 participants last post by  SD515 
#1 ·
My goal is to install a new 20A single pole breaker to be used solely for a 125V/20A HFCI outlet. Unfortunately when I opened up the breaker box I realized that there was only 1 empty hole available on the neutral bus bar.

However, I did notice that there were 2 unused ground bus bars on either side of the breaker box that were labeled "Equipment ground only". So my question is can I use the last remaining hole on the neutral bus bar for the neutral wire and then attach the ground wire to the "equipment ground only" bus? If that's not possible then how would you suggest installing the new breaker with only one hole available on the neutral bus bar?

Would it be possible to attach a small section of ground wire to the neutral bus bar, attach the other end to the equipment ground bar, then attach both the neutral and ground from my new outlet to the equipment ground bar? Since neither of the equipment ground bars are being used at the moment I thought it might be possible to use one of them to extend the neutral bus bar. But I'm not a professional electrician so there's a good chance that I'm suggesting something that either won't work or isn't recommended. :)
 
#2 ·
So my question is can I use the last remaining hole on the neutral bus bar for the neutral wire and then attach the ground wire to the "equipment ground only" bus?
Yes, that's the way you should do it.

This will work in any situation. Putting the grounds and neutrals together on the same bar can only be done in the first disconnect so you have to be mindfull of that. But in your situation just do as you proposed.
 
#3 · (Edited)
Not trying to hijack this thread but I guess I am:( but it does seem appropriate.

Assuming all the slots in a neutral/ground buss( at the main panel/ first disconnect location) are full. Can you take 2 neutrals off the buss and pigtail them to a single wire and connect to one slot on the buss. Thus freeing up a slot on the buss.

Making sure that the neutrals are on different legs of the panel (think multi-wire branch circuit).
 
#6 ·
Though it has been interesting reading all the resourceful ideas. The situation faced by the op was answered by Proby in post #2. Everything after that is irrelevant to what 7green is dealing with.
 
#7 · (Edited)
Extending Neutral bus {Neutral bus full]

Reading the original message, and Probys reply, I have the same problem. I would like to clarify that I can do the same; In my case I have a 400 amp Service outside that feeds a 200 amp SquareD HomeLine panel at the house in the garage which has a 200 amp breaker of course, and all branch circuit breakers are here too. Do I consider this my Main? The green screw is NOT installed in this panel. Neutral and ground wires are mixed on one (left hand) bus bar and the second bar (right hand) has nothing but ground wires on it. Although this panel still has room for three more breakers, only one position is left in each of the aforementioned bars.

What I want to do is to add a HOM280, 80 amp dual breaker here in this 200 amp panel with 2-2-2 AL wire plus #4 AL ground wire to feed underground to my shop building. I am thinking I will add a new equipment grounding bar to the metal surface of the box where screws are provided to add one of these. Then I would move some of the existing ground wires from the bar that currently has mixed neutral & grounds now.

This would free up space for me to add an LK100AN "Neutral Terminal" onto this existing bar so I can connect the #2 Neutral wire that feeds over to the shop. I would put another one of these LK100AN's onto the new equipment bar and connect the #4 AL ground wire that also goes to the shop.

I hope I made sense, and hopefully what I indicated above is ok to do?
 
#8 ·
For both panels ifthis is the first disconnecting means after the meter than grounds and neutrals can be on same term strip. Storyoilco would need to install gren ground screw or strap.
2 grounds wires can be under same term but only 1 neutral wire is allowed under a term
 
#10 ·
You said you have a 400A service outside. Does that have a disconnect in it, and is the first disconnect after the meter? That’s what it sounds like. If so, that would be your main disconnect. Your 200A panel becomes a feeder panel, which is why the green bonding screw is not installed, and shouldn’t be. The neutral and ground wires should not have been mixed in the 200A panel either. In feeder panels, the neutrals have to be isolated from the grounds, including the panel itself.

You are correct in adding a second ground bar to your 200A & moving the grounds off the neutral bar. Same thing when you put in the panel in the shop fed from the 80A breaker. It will also be a feeder panel…grounds and neutrals separated and don’t use the green bonding screw. Also, sounds like your shop is a detached building…which will require at least one ground rod. Make sure you have a hole in your ground bar to accept the grounding electrode conductor.
 
#11 ·
re: neutral bus full

SD515 -
I was just puzzling over that. You are correct re the 400 amp meter panel has a Main disconnect in it, therefore the panel at the house, in the garage will be fed from that main and thus as my groggy mind recalls what is correct, is indeed a Feeder panel as will my new one at the shop.

It is interesting that the one in the garage passed inspection when house was built for us as all of the branch circuits in it were there. This is correctable. Quality of work by the electrician otherwise looks superb and to code as best as I am re-loading into my brain. It has been many many years since I've done any of this.

Ok re the ground rod(s) at the shop. I put in two eight foot, 5/8 diameter rods, spaced six feet apart.
 
#12 ·
SD515 -
I was just puzzling over that. You are correct re the 400 amp meter panel has a Main disconnect in it, therefore the panel at the house, in the garage will be fed from that main and thus as my groggy mind recalls what is correct, is indeed a Feeder panel as will my new one at the shop.

It is interesting that the one in the garage passed inspection when house was built for us as all of the branch circuits in it were there. This is correctable. Quality of work by the electrician otherwise looks superb and to code as best as I am re-loading into my brain. It has been many many years since I've done any of this.

Ok re the ground rod(s) at the shop. I put in two eight foot, 5/8 diameter rods, spaced six feet apart.
My understanding is that all panels after the main disconnect (in your case, the 400amp d/c outside - IF it has a disconnect, i.e. breaker, in it) are subpanels, and the grounds and neutrals are to be kept separate.
 
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