1

House was built in 50s or 60s, and there was a bundle of wires all grounded to the main ground lug. I removed them and began to separate to disperse them along the ground bar, and three of them are hot. Also they are a mixture of white and bare wires. Do I connect them to the ground bar?

1
  • 1
    Please do not tell us you were doing this will power on to these circuits?!? Jan 8, 2016 at 21:17

1 Answer 1

3

The neutrals are hot until they're connected to the neutral bus whenever the load is connected (switched on or whatever). You have a very dangerous situation there whenever they're disconnected. You should never disconnect neutrals or grounds unless the associated hot is disconnected or the breaker switched off.

More info and explanation

In a main panel, ground and neutral are "bonded", and they share one or more bus bars. The neutrals and grounds for a particular branch circuit should never be installed together under a single screw. It is a code requirement that each neutral be terminated one per hole with no other wires. This prevents inadvertent and dangerous detachment of additional neutrals when working with a single screw.

UPDATE: Here's a good discussion on 408.21, the section that covers this issue. My interpretation is that neutrals must be individually secured, but grounds can be doubled (or even tripled) when the hardware allows. Confusion often stems from the terms "grounded" and "grounding". The former refers to grounded neutrals, and the latter to (typically) bare ground conductors.

10
  • computer spazzing when I tryed to up vote I hope it worked. never pull a neutral with the breaker on + from me most folks dont have a clue. but only 1 ground wire per screw 2 under screw is a code violation
    – Ed Beal
    Jan 8, 2016 at 21:14
  • 2
    @EdBeal, most modern panels and ground bars can legally and safely accept two or even three ground wires of the same size per hole. This typically only applies to #14-10. Jan 8, 2016 at 21:18
  • Thanks for the correction,Speedy. That calls into question either 1) work I've seen from electrical contractors in the last 20 years, or 2) my own memory.
    – isherwood
    Jan 8, 2016 at 21:26
  • Sorry Speedy NEC 408.41 states each grounded conductor SHAL terminate in a individual terminal that is not used for another conductor. So there are no safe ways to put 2 grounded conductors under a screw.this has been code for many years.just checked an 02 code book still there 408.21 in 02 book
    – Ed Beal
    Jan 8, 2016 at 21:26
  • 3
    guys, when @SpeedyPetey referenced "ground wires" he was talking about grounding conductors, which indeed can be doubled up on the ground bar. The grounded conductors (neutrals) can never be. Jan 8, 2016 at 22:32

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.