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Feeding wires from a main panel w/o separate neutral & ground

Feeding wires from a main panel w/o separate neutral & ground

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Old 07-18-14, 02:50 PM
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Feeding wires from a main panel w/o separate neutral & ground

I'm in the process of powering an outdoor subpanel and I've pulled my 3 main wires through. Trouble is, the neutral and ground wires in the main panel are on the same bus bar. Everyone says that neutral and ground should be separated in the subpanel, and I agree. On the new panel there are separate bars, but where should I source my green (ground) wire from? If I'm bringing it over from a panel where they are not separated, I fail to see the point in bringing both a white and a green. Should I tie that in with my (original) ground rod instead? Obviously I want to do this the right way. Would appreciate any help with this!
 
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Old 07-18-14, 03:45 PM
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If the service panel you ran the supply from has the first over current protection device the ground and neutral will be connected. The EGC and neutral for the subpanel in that case can both be connected to the neutral.
I fail to see the point in bringing both a white and a green.
It is a safety issue.
Should I tie that in with my (original) ground rod instead?
No your ground does not serve the purpose of the EGC. The EGC is to clear faults (shorts). The GEC is to mitigate atmospheric charges. In addition to the EGC from the main panel you will need a ground rod at the subpanel.
bus bar. Everyone says that neutral and ground should be separated in the subpanel, and I agree. On the new panel there are separate bars,
If both are on insulators they are neutral bars. You need to add a ground bar.

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Old 07-18-14, 07:15 PM
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By isolating the ground from the neutral in a sub panel you remove the chance for current to flow on the metal parts of the system like the panel enclosure.
 
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Old 07-18-14, 08:13 PM
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When the subpanel has two bus bars, both on plastic mountings, you can use one for ground wires (equipment grounding conductors) under these conditions:

1. There are enough holes in the other bus bar for all of the neutral wires including the feed neutral, one per hole,

2. You remove a jumper (if any) between the two bus bars.

3. You bond the bus bar for grounds to the panel using a green screw furnished for that purpose and which perhaps digs into the panel back, or using a jumper wire from one of the bus bar holes to the panel back held on with a screw not used for other purposes.
 
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Old 07-18-14, 08:45 PM
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I find it easier to add ground bar(s) rather separating the two neutral bars. More holes are better anyway.

In addition to the EGC from the main panel you will need a ground rod at the sub panel.
You only need a ground rod if it is a separate building, as Ray's picture shows.
 
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Old 07-21-14, 07:12 AM
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Thanks for all of the helpful information. That helped clear up what I need to do at the main panel. As for the new subpanel, the neutral bar is isolated while the ground bar is bolted right to the panel, so no need for modification.

For the ground rods, I have already driven them into the ground, so they're in there now. For good measure I will use one for the bonding ring and the other for the panel and filter pump. That way the inspector will have nothing to complain about (hopefully).
 
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Old 07-21-14, 08:01 AM
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Pool equipment does not need, nor does the code require grounding electrodes.
 
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Old 07-21-14, 08:23 AM
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Regardless of what else is connected to them, the two ground rods need to be joined together (bonded) using #6 copper wire or equivalent.

The interconnection can be piecemeal, namely making use of any pre-existing #6 copper wire used as grounding electrode conductor.
 
 

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