4 Wire to Sub Panel

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  #1  
Old 10-19-12, 10:48 AM
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4 Wire to Sub Panel

Hello. I have a meter/main on the outside and a main/sub panel in the basement. I know I need the 4 wire from the meter to the sub.

My basement panel has two neutral/ground bars (see pics). As seen in the pics one side has a lug for the neutral wire and the other side a lug for the ground.

My question is do I need to attach the ground wire to the box or to the shared neutral/ground bar. (the two bars are connected and isolated from the box).
Thanks

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  #2  
Old 10-19-12, 11:00 AM
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You need to purchase and install separate ground bars. Those are the neutral bars.
 
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Old 10-19-12, 11:07 AM
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That's what I thought...thanks
 
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Old 10-19-12, 01:25 PM
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Don't attach the bond. That's the copper thingy with the green screw through it near the bottom of the right neutral bar.
 
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Old 10-19-12, 04:23 PM
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My question is do I need to attach the ground wire to the box or to the shared neutral/ground bar. (the two bars are connected and isolated from the box).
Looking at your picture, I don't see that the two installed bus bars are connected. It looks to me as though they are electrically isolated from each other as well as from the box. There also appears to be one bonding strap available, next to the bar on the right.

If that's the case, you don't need to buy and install any additional bus bars. You should connect the incoming EGC to the bar on the right, bond that bar to the box, and terminate all of your branch circuit grounds there. Terminate the incoming neutral to the bar on the left and terminate all of your branch circuit neutrals there. That bar remains isolated.

Terminate the two hot feeders to the two lugs at the top of the buses for the circuit breakers - black on the left and red on the right.

Tech Note: To determine whether the bus bars are electrically isolated from each other, test between them for continuity.
 
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Old 10-19-12, 04:59 PM
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The two bars are connected by the black insulated buss running between them.
 
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Old 10-19-12, 05:05 PM
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If that's what that is, then they are a pair of neutral bars, must remain isolated, and a separate, bonded ground bus is needed.
 
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Old 10-19-12, 07:48 PM
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Yes the two bars are connected. I went ahead and installed a separate ground bar. And did not connect the bonding strap.
Thanks to all for your help.
 
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