Another Subpanel Question


  #1  
Old 01-09-04, 02:11 PM
DIY_Dave's Avatar
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Question Another Subpanel Question

I'm adding a subpanel to service the basement area I am remodeling. Aside from the ground running back to the main in the 6/3 cable I am using between these panels, are there any other grounding requirements? i.e. does it require a separate #6 ground cable?

Thanks in advance.
 
  #2  
Old 01-09-04, 02:22 PM
charlie b
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At the sub-panel, the neutral bus and the ground bus must not be connected to each other. The separation must be maintained all the way to the main panel. Therefore, if the sub-panel is a 120/240 volt panel, then the 3 wires in a 6/3 would be for the two hots and the neutral. This is not enough. You also need a wire to serve as the equipment grounding conductor (EGC). If the feed to the sub-panel is 60 amps or lower, then a #10 EGC is sufficient. If it is between 60 and 100 amps, you need a #8 EGC. Reference is NEC Table 250.122.
 
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Old 01-09-04, 05:33 PM
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The bare #10 inside 6/3NM is perfectly adequate to ground your sub-panel.
Depending on your panel you may need to buy a separate ground bar which is screwed right to the back of the panel box. The neutral bond screw/strap included with the panel is not used.
 
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Old 01-09-04, 08:44 PM
J
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Charlie made the assumption that your 6/3 does not include a bare grounding wire. Speedy made the assumption that it does. Follow the advice of whomever made the correct assumption.

Do not reground your same-structure subpanel to a water pipe or grounding rod. The grounding conductor from your main panel is all you need or want.
 
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Old 01-10-04, 07:46 AM
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Do they even make cable without an EGC anymore?
 
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Old 01-10-04, 08:11 AM
J
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Yes, but they don't carry it at the places DIYers shop, so we usually just assume it.
 
 

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