Wiring A Garage | Tips For Planning Your Workshop Or 240 Volt Circuits. If you use your garage as a workshop, I would recommend installing a 240 volt circuit, or at least having that capacity available. There are lots of power tools that require 240 volts - full size air compressors, many welders, and some of the bigger table saws, wood lathes, etc. Electrical Wiring for a Garage Workshop - Ask the Electrician Electrical Wiring for a Garage Workshop. The project and circuits to be installed are the following: I will use two 30Amp circuits, 3 wire + equipment ground, #10 wire, in 3/4″ underground PVC conduit to provide the power to the garage. I plan to install a 30Amp load center in the garage with two 20Amp circuit breakers. Can I use an MLO..