Out of space on Neutral Bar

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  #1  
Old 09-17-07, 10:52 AM
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Out of space on Neutral Bar

I'm adding a new grounding bar to my service to complete a much-needed panel reorganization to accomodate replacing my 60+ year old wiring with new NM cable, AFCIs for the kids room, etc. Plus the previous owner seemed to 'abandon ship' on projects before their time (found wire-nut connections plastered over in the walls with no boxes, improper ground bonds to boxes, bare, energized wires nailed to joists in the basement, etc.)

I ran out of space on the neutral bar in the main service for the returns and ground wires. Note that I DID NOT overload the panel with tandem breakers or anything goofy like that -- it seems insufficient from the manufacturer -- the neutral bar was short spaces after the original installer added water pipe and ground rod bonds.

So I am connecting the original panel ground bar to the neutral bar with a #6 jumper, and adding a third ground bar to the panel (also connected to the neutral with a #6 jumper -- I am edgy about fault currents on the ground conductor, plus I don't like the often-performed practice of 'doubling up' neutral connections). The new ground bar is made for the panel (a Crouse-Hinds 100A panel installed about 1993), and I am mounting it to existing drilled and tapped holes in the panel itself (i.e. I am NOT modifying the panel). I _think_ this is OK, from what I have read -- it seems to depend upon the inspector.

My question is, I would like to install the ground bars such that the wire enters them from the same direction that the hot wires enter the breakers to give myself more room to make the panel neat and tidy. The problem is that this seems to put the ground bar about 1/4" from the outside edge of the breakers when they are installed. No mechanical interference, just... it's close.

Is there is a problem with this idea? I can flip the ground bars the other way, but there is only about 1" between the outside edge of the breaker column and the ground bar... it seems very cramped to me and you end up jockeying ground and neutrals around in a very cramped space.

Thanks in advance...
 
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  #2  
Old 09-17-07, 11:57 AM
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When a panel manufacturer adds a neutral bar, he assumes that the panel will contain a mixture of 240-volt and 120-volt circuits. Perhaps you have all or mostly 120-volt circuits and are using more neutral wires than usual.

Your solution, however, is standard and fine.

I'm not sure why you want the grounding wires to enter from the same direction as the hots. I'm not sure why that is necessarily neater, and I suggest you abandon this idea.

I'm sure you know that the oft-performed practice of doubling up neutrals is a code violation, so I'm glad you're not going to do it.

I'm not sure exactly what your concern is about "fault currents on the ground conductor". In fact, I'm not sure what you mean by "ground conductor". Are you talking about the "grounded conductor" or the "grounding conductor"? Note that the purpose of the grounding conductor is to conduct fault currents, so I don't know why you'd be concerned about it.
 
  #3  
Old 09-17-07, 01:24 PM
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Hi John,

Thanks for the reply.

I have mostly 120V circuits and a couple of 4-wire 240 circuits. Plus, the panel manufacturer allows 4 tandem breakers in specific positions on the panel, so those were populated with tandems. But no more than allowed by the manufacturer.

The reason that I am thinking of orienting the ground bars as I described is that they mount on these 'L' brackets that offset them. One way you get 2" of space beside the ground bar to insert wires, but the bar is 0.25" from the side of the breakers (and the ground/neutrals enter in the same direction as the hots).

The other, the ground bar is in the center of the panel free space, but you end up with only about 1" of space to play with , and the grounds/neutrals end up smooshed into this space (between the ground bar and the side of the breaker).

As for 'fault current', if you have a fault current from line-ground or neutral-ground on a feeder circuit (when the circuit is carrying current), you would end up having the service panel metal case itself carrying the fault current for a brief moment, if you don't jumper the ground bars back to the neutral (which is connected to the exterior ground post and the service entrance neutral wire). Even worse, the fault current would pass via the screw threads that mate the ground bar to the case.

I have heard some people say that jumpering the grounds as I describe is fine, others say that their local inspectors may or may not tell them to remove the jumpers (I can see this on a subpanel, but on the main??)
 
  #4  
Old 09-17-07, 05:20 PM
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In " theory", the jumper serves no purpose. I agree completely with your reasoning, as I just did the same to My panel. Oddly , I had no ground bar, GEC ran directly to neutral buss bar, and -- If doubling neutrals is a no-no....
The original installer had 3 and 4 wires twisted together under the screws. I added 2 full size ground bars , and still wound up with doubles. Im not familiar with your box, but my SQ -D has spaces for additional neutral busses, which are staggered in height, so the extra wires slip under the first and screw down in the "INNER" bar. I ran the perimeter of the box with bare #6 and tied them all together. The only issue I can see is space restraints.

Without Hijacking your thread, A question....The screw holes in my ground bars were one space off from the "Nuetral Bars" . I drilled out the appropriate hole in a ground bar, and mounted the "NEW" hole in the plastic part of the gut, as opposed to the strip. The pre-existing hole is tight to the strip.

Any one have a problem with this???--A second opinion will put my mind at ease...
 
  #5  
Old 09-17-07, 05:49 PM
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All new and existing neutral bars are connected physicaly by the #6?

Make sure, if so you sound ok. None should be isolated.

As far as doubleing up...... Your a bad man!!!!

I can't condone it,but won't rip it either.
 
  #6  
Old 09-17-07, 06:44 PM
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Unclediezel:
AFAIK, GEC to neutral bar in the main panel is OK (NEC 2005)
Inspectors REALLY hate doubling/tripling ground and return (neutral). Again, AFAIK, its OK to drill out the ground bar, but NOT OK to drill out the panel, but that's not what you did.

lectriclee:
Yep, all new and existing gnd bars are connected back to the neutral with nice, hunky #6. I've had lots of electricians tell me that doubling up is OK, but, hey, it's my house, my family.

And I am an electrical engineer (though lacking the time-tested practical experience of a residential electrician), so I really respect the effects of even a loose return in a panel with even a couple of amps of current...
 
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