Bonding metal boxes with EMT connection

[Jpflex]

It would seem redundant if within a metal gang box for standard 120v System, you connected ground conductors together with a third ground conductor (pigtail) Joined between them and a listed ground screw to the metal gang box and have to repeat this at the receptacle box down stream or any consecutive box thereafter over and over when EMT conduit already bonds all metal to first point of Pigtail bonding jumper

Therefore, would an inspector fail you for not bonding every metal gang box? Or what is NEC interpretation?

 

[infinity]

Yes you need to pigtail to every box even when the EMT can serve as an EGC when the box contains splices. The wire type EGC is optional with EMT.

 

[winnie]

Putting post 2 in a different way: in any junction box where wires are spliced you are required to splice _all_ EGCs that happen to be present (with the exception of 'isolated grounds').

This means that wire EGCs and conduit EGCs must be joined.

You can avoid this requirement simply by using the conduit alone as the EGC. But if you want the redundancy of conduit and wire, you have to join them at each box with splices.

As I recall, boxes that are pull points without any splices or devices don't require a jumper between box and wire EGCs.

Jon

 

[electrofelon]

It would seem redundant if within a metal gang box for standard 120v System, you connected ground conductors together with a third ground conductor (pigtail) Joined between them and a listed ground screw to the metal gang box and have to repeat this at the receptacle box down stream or any consecutive box thereafter over and over when EMT conduit already bonds all metal

Putting aside the logic or reason for having to bond a wire EGC to a box that is already bonded by a raceway, It's redundant to run a wire EGC when you already have a perfectly good conduit EGC, so just skip it and save some time and money and pipe fill.