Ground bar for multiwire circuit sub panel?


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Old 04-19-15, 10:58 AM
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Ground bar for multiwire circuit sub panel?

I'm running a multiwire circuit from my main panel to an outdoor shed. On the shed I have a sub panel with two 20 amp breakers. My question is whether I need a ground bar on the sub panel or if I can just tie the ground wires together in the panel? I don't see any factory holes to attach a ground bar.
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Last edited by pschumac; 04-19-15 at 11:15 AM. Reason: adding picture
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Old 04-19-15, 11:17 AM
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Some brands require holes to be drilled for the ground bars. The panel label should show where to install the bar.
 
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Old 04-19-15, 12:06 PM
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For only two 20 amp circuits you don't need a subpanel. Opinion: If you are going to the effort of a subpanel it should be larger. If all you need is two 20 amp, 120v circuits a simple multiwire circuit will do the job and no subpanel or ground rod needed, just a disconnect either one intended for an A/C or a 20a DPST switch.
 
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Old 04-19-15, 04:05 PM
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Thanks for the replies.

The diagram shows that the ground bar goes to the right of the breakers. There doesn't seem to be much room there.

Yes, I only need two 20 amp circuits.so a larger subpanel isn't necessary. Good idea to use an AC disconnect switch. However, since I already have this panel installed, I'd like to make this work. Do I really need to install a ground rod?
 
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Old 04-19-15, 04:15 PM
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Do I really need to install a ground rod?
Yes, at least one. It needs to be eight feet long by one half inch in diameter minimum driven flush with the ground. Ground wire is usually #6. You can use less thnt #6 but then you would need to protect it with conduit.
 
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Old 04-19-15, 07:49 PM
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Do I really need to install a ground rod?
It's just a 20 amp multiwire branch circuit. Take out the panel and use the A-C disconnect (about $6.50 at Lowes) and you don't need to add a ground rod/rods.
 
 

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