Equipment Grounds for Mixed Voltages

[jwatts]

Installing 3 phase, 480V receptacle feed and single phase, 240v receptacle feed in a common IMC raceway. Do I need separate equipment grounds, or can I use a common ground and terminate on a ground bar at the trough where circuits are originating?

 

[jumper]

I think you may use a common ground.

250.122(C)

(C) Multiple Circuits. Where a single equipment grounding
conductor is run with multiple circuits in the same
raceway, cable, or cable tray, it shall be sized for the largest
overcurrent device protecting conductors in the raceway,
cable, or cable tray. Equipment grounding conductors installed
in cable trays shall meet the minimum requirements
of 392.10(B)(1)(c).

 

[Dennis Alwon]

You do not need an equipment grounding conductor as IMC is suitable as an egc. art.342.60 unless the specs call for it. In that case I believe one egc is needed sized to the largest OCPD for conductors in the raceway.