Originally Posted by I5runner
My detached garage is about 5ft away from my home, I would like to run 4 12/3 wires inside a 3" pvc conduit under ground to avoid having to use a sub panel in the garage. Is a sub panel required or can I save a few bucks and just run the 4 wires directly into the outlets and lights. My main panel is about 6ft from the garage if this matters.
ok there are a few issues with this. first romex is not allowed in counduit unless it is sleeved for physical protection only, it is also not allowed underground, (type uf cable is and it can be direct burried). second you would would have to derate the ampacity of the wire based on the number of condutor in the conduit per NEC table 310.15 (B) (3) (a) you would be looking at a 50% derate of ampacity.
the last part is you have to have a disconnecting means as soon as the power enters the building/garage. so you have have to have 4 double pole disconnects or 8 single pole disconnect they way you are talking about doing this. 8 would be a code violation also, so the bottom line is you really should use a sub panel. they are cheap and i would recommed that is what you use. then use the 3" conduit for you feeder wires to the sub panel. from there you can add all the circuits you want.