Grounding for multiple raceways and cable tray.

D

derekmman

New User
Location
Memphis, TN
Hello everyone,
I have a scenario on a project that we can't seem to agree on and would like your input.
I have a 480 volt, 1140amp circuit that is coming out of our MDP that is feeding a load a few hundred feet away.
It is being paralleled 3 times with 500MCM tray cable. It goes from 3 conduits, one per parallel, to cable tray back the to 3 conduits at the load end.
The question is, do we have run three separate 3/0 grounds or could we run one 3/0 in the tray and tap it at the ends for the conduit?
 
I want to make sure what "One per parallel means. Are you saying one set of Phase A conductors in one conduit, etc or do you mean one set of the phases in each conduit.
 
Each conduit will need an equipment grounding conductor that is large enough to trip the breaker-- based on 250.122. I assume you are not using the conduit as a ground.

I just realized you are asking about cable tray bonding. I would assume the tray would only need one equipment grounding conductor..
 
Each raceway needs a 3/0 EGC and the tray needs one 3/0. Note that if the tray is aluminum and has a cross sectional area of at least 1 square inch, the tray itself can be the EGC.
 
You must log in or register to reply here.
Top