2 Ground Bars in Panel

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Old 03-02-09, 06:49 AM
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2 Ground Bars in Panel

Hello,

I am installing a subpanel in my house. It is a 40 slot QO chassis with a 200 amp main. I have a 4/0 AL 3 conductor with ground running between the main disconnect and the new panel. All bonding to ground rods and water pipe is done at that main disconnect. That means I have to separate the grounds and neutrals at the subpanel.

The question I have is, if I wanted to put two ground bars on this panel, how would I go about this? The part number installed right now is pk23gta. The ground wire coming in from the service cable would go into a lug on one of the ground bars. Is there enough bonding between the chassis and the ground bar that I don't have to run another wire from one ground bar to the other? Or do I have to run an additional wire from one ground bar to the other?

Seems like a simple question, but I can't find the right search terms to find it in the forums already.

Thanks in advance for the help.
 
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Old 03-02-09, 07:14 AM
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That would be a question best answered by the panel manufacturer.

As to myself, I just drill two holes, install self tapping screws, and I also like to run a heavy gauge copper wire between the two ground bars. I like good solid ground connections!
 
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Old 03-02-09, 09:07 AM
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You do not need a wire going between the two (or more) ground bars in the same. The steel case of the panel is enough.
 
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Old 03-02-09, 09:59 AM
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Question

Originally Posted by eaglek96 View Post
The ground wire coming in from the service cable would go into a lug on one of the ground bars. Is there enough bonding between the chassis and the ground bar that I don't have to run another wire from one ground bar to the other? Or do I have to run an additional wire from one ground bar to the other?
Main Disconnect:

Both feeder ground and equipment ground wires are connected areconnected together at a ground bar in the main service disconnect. If you're adding a second ground bar in the main disconnect then a main bonding jumper is required to bond the two ground bars together. T

The bonding jumper is sized based upon the size of the service entrance conductors. I'm assuming the ungrounded service entrance conductors in the main disconnect are 4/0 alum. If that's the case the main bonding jumper has to be either a #4 copper or #2 aluminum.

Subpanel:

The feeder ground and equipment ground are not connected together at the subpanel. Isolate (float) the feeder ground (neutral) at the subpanel. The feeder equipment ground is bonded to the subpanel. Connect the branch circuits' grounds (neutral) to the ground (neutral) bar in the subpanel. Connect the branch circuits' equipment grounds to the equipment ground bar in the sub panel.


Originally Posted by eaglek96 View Post
The question I have is, if I wanted to put two ground bars on this panel, how would I go about this? The part number installed right now is pk23gta. Seems like a simple question, but I can't find the right search terms to find it in the forums already.
That looks like a SQ D part number. Who made the subpanel?
 

Last edited by thinman; 03-02-09 at 10:32 AM.
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Old 03-02-09, 10:20 AM
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The panel is a Square D QO140M200. The main disconnect upstream is a Murray 100 amp panel with a 100 amp double pole breaker that serves as a disconnect. The neutral at this disconnect is bonded to two ground rods and the water main. There are 4 conductors running to the subpanel (the QO140M200). The two black wires go to the main breaker, the white goes to the neutral bar, and the ground wire is connected to one of the ground bars (PK23GTA). I didn't want to have to run a wire from one ground bar to the other because it would look messy because they are on opposite sides of the panel.
 
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Old 03-02-09, 10:33 AM
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Originally Posted by eaglek96;1531129I
I didn't want to have to run a wire from one ground bar to the other because it would look messy because they are on opposite sides of the panel.
Are you talking about the subpanel or main disconnect panel.
 
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Old 03-02-09, 10:38 AM
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Sorry if there's confusion.

Inside the subpanel (the qo panel), I want to put two ground bars, since the pk23gta only has 23 slots, and the panel supports 40 circuits. I'm not changing anything at the disconnect.

I hope that makes more sense.

Thanks again.
 
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Old 03-02-09, 10:46 AM
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Subpanel:

The feeder ground and equipment ground are not connected together at the subpanel. Isolate (float) the feeder ground (neutral) at the subpanel. The feeder equipment ground (4th wire) is bonded to the subpanel's metal. Connect the branch circuits' grounds (neutral) to the ground (neutral) bar in the subpanel. Connect the branch circuits' equipment grounds to the equipment ground bar in the sub panel.

No main bonding jumper is required between the two ground bars in the subpanel. You don't want a parallel path back to the main service disconnect's ground bar.

Curious. Why are you installing a 200 main breaker subpanel when the the main service is only rated for 100 amps?
 
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Old 03-02-09, 10:51 AM
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Thanks Thinman,

I will be upgrading the service as well, as soon as I can afford the new meter socket/disconnect/master electrician. I am replacing one thing at a time, starting with the panel, since I needed more breaker slots immediately. It will all be done in good time, maybe once we don't need heat for a day in a couple months. Still too cold now.
 
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Old 03-02-09, 12:11 PM
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Originally Posted by eaglek96 View Post
It will all be done in good time, maybe once we don't need heat for a day in a couple months. Still too cold now.
What type of heat does the home have?

Good luck with your electrical project.
 
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Old 03-02-09, 01:19 PM
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I don't mean to complain but could we please call it a neutral or the grounded conductor as referred in the Code? "Feeder ground" and "branch circuit ground" is confusing as all get out.

Thank you. (stepping down for soapbox)
 
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Old 03-02-09, 01:47 PM
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You'll have to check the listing (or maybe the label) for that auxiliary equipment grounding bus in the subpanel but most likely it allows for multiple equipment grounding conductors per screw terminal.
 
 

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