Neutral Bar Capacity

[A/A Fuel GTX]

I've been experiencing many situations lately with neutral bars being completely full with no room for additional circuits. I've also seen more and more terminals with two conductors under the screw, usually the grounded and grounding conductor. I would assume that two grounded conductors under one terminal would not be legal. I called Square D tech support and was told that the neutral bar can only have one wire per terminal but the ground bar if present can have two wires per terminal. I'm wondering what some of you out in the field are seeing and doing when you run into full neutral/ground bars? What if you come across a neutral bar that is full in a panel where the neutral has a bonding jumper to the panel enclosure and you add a ground bar, could you land additional neutrals to this ground bar?

 

[Jhr]

Re: Neutral Bar Capacity

What if you come across a neutral bar that is full in a panel where the neutral has a bonding jumper to the panel enclosure and you add a ground bar, could you land additional neutrals to this ground bar?

Yes, if its the main panel.

 

[roger]

Re: Neutral Bar Capacity

Jhr, I disagree, an enclosure is not a conductor, a direct jumper would be needed from bar to bar.

Roger

 

[jwelectric]

Re: Neutral Bar Capacity

I agree with Roger

 

[iwire]

Re: Neutral Bar Capacity

I agree with Mike and Roger.

 

[jeff43222]

Re: Neutral Bar Capacity

I agree with Mike, Roger, and Bob.

This kind of thing is fairly common with Square-D panels in my experience. This is yet another reason I don't install Square-D panels anymore.

More often than not, when I come across this situation, the panel is already loaded to the gills, and adding another neutral/ground bar would be more trouble than it would be worth, so I sell the homeowner a subpanel installation and move enough grounded conductors to accommodate the feeder neutral. I install Siemens panels whenever possible. I've never run out of neutral/ground terminals in a Siemens panel.

[ January 06, 2006, 11:38 AM: Message edited by: jeff43222 ]

 

[A/A Fuel GTX]

Re: Neutral Bar Capacity

Thanks guys and sorry for posting the question in the wrong forum....I forgot where I was.

 

[infinity]

Re: Neutral Bar Capacity

This always seems to happen when you're on a job just adding a circuit or two and you find the neutral/ground bar full. You could simply add a grounding bar to the panel back box and move the EGC's from the neutral bar or if your really in a bind, just take a bunch of grounding conductors off the bar, spice them together, and pigtail one conductor on to the bar. The pigtail must be sized for the largest EGC.

[ January 21, 2006, 08:08 AM: Message edited by: infinity ]

 

[Jhr]

Re: Neutral Bar Capacity

I agree with the Greatness of Roger and his cool looking pictures .

 

[Shockedby277v]

Re: Neutral Bar Capacity

I'm new to this forum and see this is an older post but I would like to debate the whole enclosure is not a conductor issue. I may be wrong but I believe enclosures are a conductor and can even be used for an equipment ground in some cases. Concentric knockouts I believe are rated for a 20 amps then a bond bushing is needed. Right now, we are building apartments and installing 125 amp panels into each apartment. The bonding between the neutral and ground in those panels is just a little piece of metal that screws to the panels enclosure and inserts into the neutral bus in one of the terminals thus, utilizing the enclosure for bonding. It is green and if I remember right there needs to be so many threads on a ground screw. This may not hold true with high amp panels but these ones do. Again I may be wrong.

 

[celtic]

Re: Neutral Bar Capacity

Originally posted by Shockedby277v:
Right now, we are building apartments and installing 125 amp panels into each apartment. The bonding between the neutral and ground in those panels ....

HUH???

So each unit is not a sub-panel from a MDP and meter stack?

 

[Shockedby277v]

Re: Neutral Bar Capacity

Yes they are. Sorry I wasn't clear on that. We aren't using the bonding jumper because they are fed from a MDP. My mistake. Was just using the panels themselves for case and point.

 

[celtic]

Re: Neutral Bar Capacity

Originally posted by celtic:


So each unit is not a sub-panel from a MDP and meter stack?

Originally posted by Shockedby277v:
Yes they are.... We aren't using the bonding jumper because they are fed from a MDP. .

You had me worried for a second there.

 

[hurk27]

Re: Neutral Bar Capacity

Many panelboards are designd to have and extra grounding bar installed if used with NM cable, read 408.20, One of the worst that required this was T&B panels as they only had as many terminal openings as breaker spaces.
Some Square D panels may also require aditional grounding bars installed when NM is used as they also don't have enough terminals when NM is used.
As for double wires on the neutral bar read 408.21