I have a 60a subpanel on the side of my house for the pool equipment. There are only two conductors and a ground. Originally the only things that were probably connected were the pool pump and heater, both 240 volts. But the lack of a neutral prevents the extra spaces from being used for 120 volt circuits.

And at some point, that's what happened. There's a 120v receptacle under the panel. Apparently, whoever installed this realized the problem, and at least was smart enough not to use the subpanel grounding conductor as a neutral.

About 20 feet away from the panel, there is another circuit feeding the a/c condenser, which does have a neutral for some reason (its unused by the condenser). So, whoever installed the receptacle ran a single 12 ga conductor (in conduit) from the a/c disconnect to the subpanel and used that for the receptacle's neutral.

Yes, it's infinitely better than using the subpanel's ground conductor as a neutral, but it makes me cringe and I want to add another 120v circuit or two so I want to fix this the right way.

Seems to me I have two choices. One, replace the entire feed to the subpanel with a 4/3 cable, or run a single #4 conductor from the main panel to the subpanel for the neutral. Since you can't buy single conductor Romex, I assume I'd have to run it in conduit. The second option would be much cheaper, but is it against code or a bad idea for some other reason? Could I run the single #4 conductor in 3/8 flex conduit rather than PVC? It would be entirely in the attic.

  • 3
    how is the original feed run? in conduit or a romex-alike? Nov 9, 2023 at 9:34
  • 2
    If your original feed to this 60A panel is in conduit, you can simply pull a new neutral wire to it. If it was fed with a cable, not so much... Edit in pics of the panel with the cover off so we can see how it's been fed. With some cables you might be able to repurpose the current "ground" wire as your neutral and add a ground. Again, pics will allow the actual electricians (as opposed to me who plays one at home but is far from licensed) to make a proper assessment.
    – FreeMan
    Nov 9, 2023 at 13:25
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    Unlike a ground wire, I believe that neutral cannot be separated from the hots. It must be in the cable or the same conduit. Romex/NM-B cannot be outside of the house. Though the wall into the panel is okay, but can't be in conduit outside of the wall.
    – crip659
    Nov 9, 2023 at 13:26
  • 1
    The original feed is a jacketed cable. Through the attic and down inside the wall into the back of the panel.
    – Don Caton
    Nov 9, 2023 at 14:01
  • 1
    You haven't mentioned what sort of 120 volt circuits are wanted, but.. that outlet could be properly installed at the A/C disconnect. This might possibly require replacement of the existing disconnect with a subpanel.
    – Greg Hill
    Nov 9, 2023 at 14:57


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