How to install a new circuit in an empty slot, and then run multiple outlets off of it?
There are a lot of Code requirements you have to comply with to do this seemingly simple task safely & correctly; so I, too, will say “Call a qualified, licensed professional to do the job for you.” Now, just to let you know what you will have to contend with, I will describe, in general, what needs to be done according to the National Electrical Code – and you will probably have some local amendments to deal with as well. Contact your local Building Department before you begin (and don’t forget to obtain a Permit for the work). First, as previously mentioned, the distance is not a problem. To comply with Code requirements, I would run a single 3-wire circuit to the shed, originating on a double-pole 20 Ampere breaker (two single-pole breakers are also acceptable, under the 2005 NEC and any previous editions. Make sure they are positioned right above and below each other in the panel, to keep the neutral conductor from sharing two legs from the same side of the panel. The 2008 NEC will
This is a very basic electrical problem. Start by marking on the garage walls where you want the items, then call a qualified professional electrician to come out and install the circuits and the wiring and do the complete project. This is faster and safer for all concerned now and in the future. Typical the wire should be 12/2 wg and you can load the circuit to about 16 amps maximum, the outlets are computed 1.5 amps each and the lights need to be added. The outlets are wired in parallel. I repeat, call a qualified professional electrician to do the work. Then it will be done right and not potentially void your fire insurance for installing electrical circuits without inspections.
The loads you mention will be fine on one 20a. circuit, and the 40′ length is no problem, but there are a lot of rules to running that wire safely, (especially out of doors, but inside as well), and getting it out of your house and into the garage. Too much to go into here covering all possibilities. Outlets in the Garage will ned to be GFI protected. Get a home wiring book and lay out the best ways. It’s not undoable, but you need to do some homework.
