I have an existing 2" ID PVC U/G ductline from my house to our steel barn, approximately
400 ft. We plan to run 120/240V cable in the ductline to the barn, mainly for fluorscent lighting, and possibly one small electric 'hotplate'.What size, and type cable do you recommend? Hopefully 50 Amp min. AL or CU ? :confused::confused:

Dave Owen
Retired

Assuming worst case of 50 amps at 120 volts, you need a #1 copper wire or #3/0 aluminum to the Voltage drop just below the maximum recommended 5% Vd.