Electrical wiring for shop

[Maurice Elefant]

I am running new wire for garage shop for guitar building. I originally planned for two 20amp circuits to power 2 sets of outlets. Is this enough for bandsaw, drill press, router table, thickness sander, belt sander etc. and anything else that needs to plug in? Is there any use for a 30amp or more circuit?

[Mario Proulx]

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Run at least a 60 amp service to your shop, and from that panel, size your circuits according to use.

[Jim McConkey]

Are you planning to heat or cool the garage shop? If so, you will need an entire circuit just for that. Most of the time you will not be running more than one machine at once, but don't forget the bender and dust collector and lighting and sound system, etc which can and will be on at the same time. Most jurisdictions in the US require conduit if the wiring is not run in a wall and some require GFCI outlets everywhere in garages. Just be aware of your local restrictions. You may get away with less for many years, but if you ever sell the house, you will be forced to bring it up to code. Do it right the first time.

[Michael Lewis]

What Mario and Jim said! Run 220V to the service box and split off 115V for the individual circuits from there. Go ask your county building department regarding code for wiring. You will probably have to get permit from the same department.

The reason for building codes is safety. You can get by with sub standard wiring, until something goes wrong. If you have a fire due to overloaded wiring most likely your home owner's insurance won't cover it because the wiring is not up to code.

[Maurice Elefant]

Heating and cooling will be supplied with an add on duct from the air handler in the garage. No additional electric required. Sound system will be one zone of the whole house audio system. No additional electric needed. I was going to run a separate 20 amp circuit for lighting alone. With 2 devices running at the same time- bender and one other tool- I thought I would get away with two 20 amp circuits for outlets but then I had not thought of dust collector. I am aware of running conduit for surface wiring and other concerns regarding overload and safety. With all that said I think putting at least a 60 amp subpanel in the garage and running everything off that is the way to go. Is 60 amp sufficient?

[David King]

Maurice,

Most stationary equipment with induction motors can be wired for 220V. I'd take advantage of that whenever possible. You'll cut the amperage in half. The sockets and plugs aren't much more than their 120V cousins.

I'd also run 3/4" steel conduit around the room rather than the cheaper and easier to bend 1/2" EMT. It will be much easier to pull more wire through later. If it were my shop I'd install an outlet every 4 feet regardless of the intended layout.

[Jim McConkey]

You need to check local regulations on the conduit. PVC is required in some places (and it is much easier to deal with than metal pipe, anyway). It doesn't apply to this situation, but barn wiring in my county is required to be in PVC. Metal conduit is forbidden because of the possibility that the conduit itself can become hot if a wire gets loose, potentially electrocuting animals. If you do run metal conduit, also check if you are required to use a separate ground lead. Many people like to leave out the ground and rely on the conduit itself as the ground, but that is not allowed in all areas because corrosion and other damage can make it a less-than-adequate ground lead.

[Barry Daniels]

When I converted my finished garage into a workshop we used Wiremold to house the electric lines. It looks very finished and has the advantage that I can move it or modify it in the future.

[JC Whitney]

My vote: yes, if it's a hobby shop 60A should be sufficient - especially as you're taking lighting out of the equation. Because you're in a garage, you'll most likely have to be ground fault protected due to the possibility of a wet floor. I'd second the suggestion for receptacles every four feet or so (having spent far too many precious hours plugging and unplugging equipment).