i am designing a 320 amp service for an existing shop and future house(under construction now).
the shop is currently fed with a 200 amp meter at the begining of a drive way about 200 feet away underground(meter on 4X4 pole and no disco between it and shop panel)
the power company will change the x-former to a 320 for new house.
here is my plan i will build a stand(using maraine plywood and two 4X4's)to mount a 320 amp meter can from which i will feed two 200 amp 3R disco's one for new house other for existing shop. i will drive two ground rods here for my new service split bolt off grounding electrode for 4th wire to feed new house 200 amp sub-panel and drive two ground rods there for seperate building and all neccessary bonding(h20,gas,ect...)for new sub- panel.
I will seperate grounds and neuts from existing shop panel since this will be a sub-panel(shouldn't it already be since its 200 feet from meter?)here is where it gets tricky there isnt a 4th wire back to the meter since the previous electrician treated this as a main panel and now it will be a sub panel and require the 4th wire(ground) can i split bolt the 4th wire at the house and trench over to the shop(about 75 feet instead of the 200 back to the new 320 service)to meet the 4th wire requirement?
any thoughts will be much appreciated,
thanks h20
p.s. is a 320 considerd a parallel service?
there are two sets of line conductors single phase(which seems self explanitory) but i am somewhat confused if each disco fed from load side of meter can should follow 310.4 rules.
