What type/size of wire should I use for running power from the 200Amp service panel at my house to a subpanel at my wood shop? The length of the run is 300 feet. I need 220V service at the shop and would like to run a 70 amp circuit. I would like the wire to be direct burial, +/- 2 ft deep. Voltage drop limit is 3%.

I was told that I could use #1 THHN copper wire in conduit OR aluminum wire rated for a 100 amp circuit, but was not given a gauge/type of aluminum wire.

What size wire should I use?


1 Answer 1


Here's a good calculator that will answer your question.

It says #1 copper, 2/0 for aluminum.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.