Multiple Circuits Single Ground

[Mike01]

When installing multiple circuits thru a pull / splice box [480V & 120V] once past the splice box they will be installed in the same conduit can a single grounding conductor be installed from the splice box to the next location where the devices are installed or will each circuit of different voltage require a individual ground?

 

[charlie b]

Voltage is not a factor, when determining the size of equipment grounding conductors. So it does not matter if the circuits are 120V or 480V or anything else. And yes, you can use a single EGC to serve all circuits within a conduit. See 250.122(C).

 

[jumper]

A single EGC sized per 250.122(C) would be allowed as long as the EGCs for all circuits involved of both voltages are spliced together in your box.

A GF will trip the breaker in the applicable panel for the circuit involved.

Personally I keep them separate as far as mixing voltages, but that is a preference.

Edit: charlie b types faster.

 

[electricalist]

I think they have already answered your question. Keep in mind your bonding requirements. More than 250 volts to ground. A or c knockouts and derating when u say multiple circuits.

 

[hurk27]

Think of it this way, if you had conduit as the EGC as the NEC allows in 250.118, and we know we are allowed both voltages in the same conduit, you would have the same thing.