A job that I am bidding is calling for a 600A service with 300MCM paralleled in 3" conduit. The service disconnect is on the outside of the building and there is a MDP inside so this will be a subfeed.
They just decided to add an isolated ground for 2 pieces of equipment that are on 20A 120V circuits.
I have never had to parallel an isolated ground before so...
Can I just install a an extra 1/0 copper in one conduit in addition to the 1/0 grounding conductor in each conduit.
Or, do I have to install an isolated 1/0 in both conduits. If I did this I would have (4) #300MCM and (2) 1/0 in each conduit. This would seem like overkill for two 20A 120V circuits.
Thanks
Brian
