Electrical question.

I need to install 2 runs of #8 gauge VW-1 / THWN copper stranded wire 135 feet under ground in 3/4" PVC conduit to my outbuilding shed. With these two runs of #8 wire, with a 30 amp 220 breaker from the house end, to feed two - 20 amp single circuit's in my shed, just for lights and small 115v hand tools, what size of a unshielded copper ground wire do I need? The shed will have the 30amp breaker box, 120amp breakers and ground rod. In the shed, it won't be wired for 220, just single 120 breakers maybe 2 or 3 circuits. Thank you Don M.

Good morning Don,

Just for starters, you need to pull a four wire cable from the house to remote building. The ground wire will be in the cable,

Also, when you get the cable to the building and connect it t the panel board, you cannot bond Neutral and ground together, Remove the green screw from the secondary panelboard.

Your choice of wire size is marginal. #8 AWG wire will drop 2.5% volts over the 135 ft. That translates to a working voltage of 117 volts. A better choice would be #6 AWG. This size cable will only drop1.6 volts and get you a little higher working voltage at the end of the wire run,