These 3 wires connect this main disconnect to my sub panel in the back of the garage that powers the whole house. It runs in a conduit that serves as the ground between the sub panel and the enclosure in this picture. I am replacing the cable/conduit with a 4 wire SER cable (separate ground). How would the ground in that new cable attach to this enclosure? Neutral and ground can be bonded since this is a main panel but there is no lug available and no space on the tiny bar that’s there. Can I drill and tap a lug to the enclosure? Doesn’t seem right...

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  • Can you post a clear photo of the labeling on the disconnect box? – ThreePhaseEel Nov 12 '17 at 6:29
  • Also, why are you replacing wires in conduit with a cable? – ThreePhaseEel Nov 12 '17 at 6:30
  • I can add a picture of the inside label but I have reviewed and it only covers the connections shown. No mention of a ground wire that I can see. I am replacing conduit that runs below ceiling level as part of a garage finishing project. – gorms Nov 12 '17 at 7:02
  • is the conduit actually in the way of anything? If not, I'd just get an appropriate paint and finish the stuff a nice color (matte black maybe?) instead of ripping it apart and replacing it with a cable – ThreePhaseEel Nov 12 '17 at 7:08
  • We'll want to see the label anyhow -- it'll tell us make/model of the box, if nothing else. – ThreePhaseEel Nov 12 '17 at 7:10

So I think I am going to mount a small ground bar to the panel under the breaker and add a lug to that bar. Neutral and ground will be bonded through the enclosure.


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