Triplex or Qradruplex for overhead to sub-panel

Status
Not open for further replies.
A

A.Sinatra

Member
Currently we have a mobile Mobile Office w/ 240v, 1ph, 4w, 100A sub-panel (outdoor). The plan is to run 1-1/4"C from panel and sub-panel to weatherheads. The span distance is currently ~45'. Using 3#2 from panel to sub-panel and #6 from 2x10' ground 5/8" rods spaced 6' at the location of the sub-panel. I have heard about using Quadruplex for grounding, but doesn't code req. the sub-panel its own ground because it is not part of the ex. building?

Thanks.
 
If it were a mobile home, I'd direct you to 550.32 & 550.33, but since its a different type building, I'd say look at 250.32 in the '05 NEC. Definately 4-wire. Also look at the nameplate on the mobile building. It will probably indicate that the building is intended to be served with a 4-wire feeder. :smile:
 
A.Sinatra said:
I have heard about using Quadruplex for grounding, but doesn't code req. the sub-panel its own ground because it is not part of the ex. building?

Thanks.
Click to expand...
Code requires a 4 wire feeder. You must have a main disco and also drive 1 or probably 2 ground rods. Read Fred's references.
 
A.Sinatra said:
I have heard about using Quadruplex for grounding, but doesn't code req. the sub-panel its own ground because it is not part of the ex. building?
Click to expand...
Actually, you need both. At the supply end, treat it like any feeder, but at the load end, treat it like a service.
 
Status
Not open for further replies.
Top