BurbMan wrote:
I re-purposed existing buried 3/4" PVC conduit that used to feed the old detached garage with a 20a circuit. I used the old #12 wire to pull new #10 through the conduit back to the panel, and upgraded the breaker from 20 to 30. I considered going to #8 because of the distance, but was afraid it wouldn't pull through the 3/4" conduit.
If you ever wanted to upgrade to #8 (plus ground), it shouldn't be a problem to get it in 3/4". Using plenty of dishwasher liquid soap helps. To keep the pulling end of the new wire as small as possible to pull it easier, you can twist the new/old ends together and solder them and wrap with a bit of tape. Then simply pull hard, lol!