0

Our building (built in 1960) has 5 sub panels everything being run in rigid or emt conduit. The neutrals are isolated. If I need to add some 15A receptacles can I add a ground bar to panel cabinet without running a ground wire back to the main about 40 ft away.

3
  • It would help to note where you are located and what kind of building it is. In the US, at least, there are restrictions on what can be done in commercial & rental properties by DIYers.
    – FreeMan
    Commented Sep 16, 2021 at 11:22
  • I think this question is really about what is the proper way to attach neutral if it is needed generally speaking.
    – r13
    Commented Sep 16, 2021 at 16:42
  • Are you adding new circuits in metal conduit or cable like Romex or MC?
    – DrSparks
    Commented Sep 19, 2021 at 4:08

3 Answers 3

1

You don't need any ground bars or ground wires at all.

All of your wiring is being done in metal conduit. The metal conduit successfully carries the grounding for you.

Simply extend the metal conduit to your new receptacle locations, fit metal boxes, and fish individual black and white THHN wires through the conduits.

If your notion is to do the additional circuits in Romex, forget it. The original builders would have done that if it was legal.

1
  • The OP did not specify the wiring method for the new circuits. Also, how do you derive the conclusion you made about the reason for using all EMT? Houses are wires in EMT all over here in WI and we love our Romex more than cheese!
    – DrSparks
    Commented Sep 19, 2021 at 4:11
1

If metal conduit is installed properly then it serves as the equipment grounding conductor, and an additional wire is not required. If you choose to run one it needs to be sized per NEC Table 250.122.

Since you have no ground bar I would take a moment and verify that the panels were installed correctly and the bonding screws or straps are NOT installed in the sub-panels.

Normally the model number for the correct fitting UL/CSA/ETL Listed ground bar can be found on the label inside the panel door. Normally Inspectors won't call out a non-listed ground bar if installed properly but they can and have.

-1

I think the OP is considering adding additional circuits to the panel via Romex. If so, yes you can just add a ground bar to the sub panel and you don't need to run a ground wire back to the main panel as the conduit serves as the equipment ground conductor.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.