1

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...

enter image description here

enter image description here

gorms
  • 53
  • 1
  • 5
  • Can you post a clear photo of the labeling on the disconnect box? – ThreePhaseEel Nov 12 '17 at 06:29
  • Also, why are you replacing wires in conduit with a cable? – ThreePhaseEel Nov 12 '17 at 06:30
  • 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 07:02
  • 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 07:08
  • 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 07:10
  • Is the conduit metal its entire length? If so, the conduit is the ground. There's not a single green or bare wire in my entire factory building, it's all in EMT. Going from conduit to cable is a huge downgrade from a reliability and maintainability POV... I wouldn't do that. – Harper - Reinstate Monica Nov 12 '17 at 07:50
  • I have added a picture of the label. The conduit is in a really bad place to accommodate in the garage upgrades. It crosses diagonally across the garage ceiling, several inches below the 8 ft ceiling height, interfering with where lights would go and storage areas above the ceiling joists. There are some 220v circuits that use EMT conduit grounds to the sub panel (which I’ll keep) but there are many other 110v circuits that use bare copper ground Romex wiring. I really want this thing gone! – gorms Nov 12 '17 at 18:58
  • Have you considered replacing the conduit with a more suitably placed conduit run? – ThreePhaseEel Nov 12 '17 at 19:16
  • That’s becoming an option as I encounter more issues but the ceiling design would make that difficult. There will be a raised area in on spot that follows the roof peak to allow storage on top of the 8ft ceiling. I have already run SER cable where I want it and have a new sub panel to replace the aging panel that is low on spaces. – gorms Nov 12 '17 at 23:28

1 Answers1

1

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.

gorms
  • 53
  • 1
  • 5
  • Bonding neutral and ground at the sub-panel is a violation of code, I believe. See https://diy.stackexchange.com/questions/28618/how-do-i-properly-ground-my-subpanel-that-only-has-one-neutral-ground-bar – Jean-Paul Calderone Dec 18 '17 at 13:13
  • 2
    The bonding I mentioned would be inside the main breaker, not the sub panel. – gorms Dec 19 '17 at 20:55