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#17275 - 11/23/02 04:23 PM Equipment ground bar
Electricmanscott Offline
Member

Registered: 01/12/02
Posts: 1478
Loc: Holden, MA USA
Helped out a fellow sparky today on a remodel job. Panel was full, added a few mini breakers. The neutral bar was also full so he installed another ground bar. He connected the egc's and neutrals to this bar. This is in a service panel where the main ground bar is bonded to the panel. He insists it's ok but I don't think so. I have never thought about doing this so I haven't given it much thought. Ok guys discuss!

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#17276 - 11/23/02 04:30 PM Re: Equipment ground bar
txsparky Offline
Member

Registered: 05/25/01
Posts: 578
Loc: Magnolia,.Texas U.S.A.
Hmmmm...
That would make the neutral solely dependant on the mounting screws used.Doesn't sound like a good idea to me.There should(IMO)be a jumper wire installed from the existing bar to the new one.
_________________________
Donnie

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#17277 - 11/23/02 04:36 PM Re: Equipment ground bar
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
You'd have neutral current flowing through part of the panel's outer casing during normal operation.

That doesn't sit well with me.

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#17278 - 11/25/02 04:12 AM Re: Equipment ground bar
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
Paul,
remember, our entire system from the MBJ to the x-former is a combo noodle/grounding conductor.
(that evil noodle of ours...the root of many problems here....)

The 02' has dictated that all noodles be under dedicated terminations, so this then creates a space problem for which added G-bars is going to be a common fix.

Now i'm wondering about how to obtain a 'floating' G-bar for similar sub-panel dilema's

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#17279 - 11/25/02 06:51 AM Re: Equipment ground bar
HotLine1 Online   content

Member

Registered: 04/03/02
Posts: 6804
Loc: Brick, NJ USA
Gentlemen:
If it's the main panel, with the main disco, then that's where the neutral is bonded to the ground conductors, correct?
If you are adding another termination bar (neutral/ground) the bar you are adding should (IMHO) have a jumper connected to the "factory" bar. The "jumper" should be sized according to the incoming neutral that is connected to the "factory" bar.

If it's a sub-panel, then there has to be a "ground" bar, and an "isolated" neutral bar, with a "ground" and "neutral" conductor for each.

If the "added" bar in your scenario is "mounted" to the panel enclosure, then you are using the panel enclosure for a "neutral & ground connection back to the "factory" bar & bond. The current passing through other "grounds" depending on the resistances. Not Good.

Hopefully my explanation above is clear enough to understand.
John
_________________________
John

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#17280 - 11/25/02 09:00 AM Re: Equipment ground bar
Redsy Offline
Member

Registered: 03/28/01
Posts: 2138
Loc: Bucks County PA
It would have been better to relocate the grounds from the original neutral bar to the new ground bus to free up the spaces for the new neutrals.

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#17281 - 11/25/02 09:04 AM Re: Equipment ground bar
sparky66wv Offline
Member

Registered: 11/17/00
Posts: 2339
Loc: West Virginia
And still have a #4 bonding jumper between the bars...
_________________________
-Virgil
Residential/Commercial Inspector
5 Star Inspections
Member IAEI

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#17282 - 11/25/02 10:06 AM Re: Equipment ground bar
ElectricAL Offline
Member

Registered: 10/10/01
Posts: 615
Loc: Minneapolis, MN USA
E Scott,

Interesting twist!

The problem is that the branch circuit neutral current is forced to return to the bond point through the enclosure of the service, even though we're only talking about half a foot or so. This applies to each neutral that is connected to the added ground bar.

That "half foot or so" of sheet metal can't be a neutral, even though its the service disco.
_________________________
Al Hildenbrand

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#17283 - 11/25/02 12:38 PM Re: Equipment ground bar
jes Offline
Member

Registered: 07/12/02
Posts: 103
Loc: CT
My Square D info says that the add-on bar is for equipment grounding ONLY. The factory installed neutral bar(s) are required to have a minimum number of terminals for landing neutrals based on the number of circuits the panel is arranged to supply. Where there are a large number of equipment ground conductors they MAY be landed more than one to a terminal IF the panel is so listed (and marked) OR an additional bar kit must be installed. Terminals used for equipment grounding are treated differently than those for neutrals because the connection does not undergo the cyclic loading and expansion/contraction of the current carrying neutral.

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#17284 - 11/25/02 01:10 PM Re: Equipment ground bar
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
 Quote:
That "half foot or so" of sheet metal can't be a neutral, even though its the service disco.


then what do we can an all mettalic service ?

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