Jack of too many trades..
Join Date: Aug 2013
Location: St. Louis
Running 220v/100a to my Detached Garage/Future Shop
Aside from recovery from a broken wrist, the biggest hurdle to me setting up my shop and getting back to serious woodworking at the new house is the inadequate electrical power in the 20x24 detached garage.
My old shop was in my basement right near the main breaker box, so running 220v service for my Unisaw was trivial. Now, I'm looking to set up shop in a detached garage about 45 feet away from the main house. The plan is to set-aside 10x20 feet of space for my 1967 Volvo (plus space for spare parts & automotive tools) and use the rest of the space as my new woodshop.
The garage has a little power already... one 15amp circuit for the garage door opener, lights, and a single GFCI outlet. Period. The power runs from the house in a PVC conduit, under an asphalt driveway, and surfaces at an elbow before entering the garage on the side wall. There's no sub-panel, just a master flip switch for the whole place. Not at all adequate for much anything.
Between my Tablesaw, Radial Arm Saw, Air Compressor, Dust Collector (and eventual Mig welder), I know that I need two or more 220v circuits, plus a couple dedicated circuits for lights, chargers, and smaller power tools. From other threads on this forum, and some web searching, I know that I'll need at least 60 amp service to the garage - probably 100 amp, just to be sure.
I've read up and watched a few videos on the topic and I realize that I've got more factors here than just the breaker size, wire gauge, and outlets per line.
I'm not afraid of doing my own electrical work, but I expect that I'll need to contract this out due to the complexity with wire depths, grounding, code-compliance, and general safety. I've never wired anything larger than 20 amps by myself, and 60 amps with knowledgeable direction.
That said, I was hoping for some opinions on how to tackle this project, even if I pay someone else to actually do the work. If I do pay someone to do this, I want to have the right information available. What sort of key information items do I need to establish (e.g. existing wire depth, total amps needed, etc.)?
I think what needs to happen is this:
1) add a service panel in the garage
2) replace the 40-50ft of wires in the buried pvc conduit with 100 amp appropriate gauge wires
3) add 100 amp breaker to my indoor panel (there's plenty of space for one)
4) hook up everything (use anti-corrosion paste if aluminum wire is used for the run)
5) add supplemental ground rod by garage..?
Whether I do this myself or contract it out, does it appear that I am in possession of the relevant key bits of information? Am I overlooking anything really important with this sort of upgrade. If I do contract this out, is there anything else I should be asking about?
My deceased father-in-law generally advised me on electrical matters, but that's no longer possible w/o a Ouija board.
Thanks for any thoughts and advice.
Last edited by RepairmanJack; 09-22-2018 at 12:16 PM.