Grounding dc in an ac panel

[Ray D]

Have a dc ground coming in the same conduit as some ac wires, is there any reason I can't connect a dc ground in an ac panel, I would just run the dc ground out to the same chassis point as the ac.

Ray D

[JackConrad]

That would work, although I am not sure about meeting code.  Jack

[Sam 4106]

Hi Ray,
The National Electrc Code (NEC) does not allow both AC and DC wires in the same conduit nor DC wires in an AC panel. It would be safer to remove the DC wires from the conduit and then there would be no need to ground a DC wire in an AC panel.
Thanks, Sam 4106

[Ray D]

Sam,

Only have one conduit going to this area, do you know what the reasoning is for this code, it is not communications???

Ray D

[Len Silva]

The reason is that the code does not allow dissimilar voltages in the same conduit so that a failure or wiring error does not introduce high voltage into circuits not designed for it.  There is also the possibility of induced AC voltages that might cause harm or noise.

Personally, being a code wonk, I would not do it.  That said, if it only a ground bonding wire, connected only to the frame ground (and not the neutral), there is probably no risk.  I doubt that the code ever considered that configuration as it would come up so infrequently.

If it is a current carrying conductor (the DC return for some type of load) and not just a bond,  then I definitely would not do it.

[HighTechRedneck]

From what you described, the ground wire is just going to get chassis grounded anyway.  Is there a place close to the other end to chassis ground it?  Then you could do away with the DC ground wire in the conduit altogether.

[Sojourner]

Amen to HighTechRedneck.

About chassis grounding in buses....it a waste of time, money to conduit the ground wire when it is already neutral (zero voltage). However, it does carry current to complete the circuits which the metal chassis or framing is your base line grounding whether it positive ground or now day is negative ground.
Conduit is primary for:
1)   DC Positive wires
2)   Signal wires
3)   Shield wires
4)   AC wires (both ground & hot line)

Hi Ray,
The National Electrc Code (NEC) does not allow both AC and DC wires in the same conduit nor DC wires in an AC panel. It would be safer to remove the DC wires from the conduit and then there would be no need to ground a DC wire in an AC panel.
Thanks, Sam 4106

FWIW

Sojourn for Christ, Jerry