Wiring your shop
So, you’ve added a table saw and a dust collector to your collection of large stationary tools. You’re happy with your purchases and are making more and more wooden projects. In fact, it’s going so well that you are now thinking of buying more equipment. Unfortunately, your present electrical system will not handle the load.
Before opting for a short-term solution, such as adding just one circuit to handle the extra load, why not look at your future needs right now? Make a list of the equipment that you will someday acquire. Make a scale drawing of your shop floor and of the equipment that will fill it. The equipment drawings can be simple box representations. Be sure to include workspace with each unit. For example, a table saw top isn’t that large, but once you add the clearance space in front and back for cutting a sheet of plywood there is a significant amount of area required. Now place your equipment cutouts on the shop floor and move them around until you get them set up the way you want. Don’t forget the upgraded lighting that you may want to install so you can see what you are doing with your new equipment.
Make another list separating your equipment into units that will run on 110 and those requiring 220. Try and run everything you can on 220. The same 2-hp motor will draw half the amps on 220 as it will on 110. This will help you decide how many circuits will be needed and where the plugs will go. Pay attention to what equipment will be running at the same time. If you have the table saw, dust collector and air compressor on the same circuit you could be in an overload situation. You will be running the collector at the same time as the saw and if the compressor should happen to kick in, the breaker will likely trip. Clearly some equipment should have it’s own circuit. These would include anything that draws a lot of current such as larger table saws, dust collectors and large air compressors. Be aware that some large motors will draw more than the 15amp rating of a standard plug and breaker combination. They may draw 17 amps, in which case a 20-amp circuit would have to be installed.
Also, take into account how many people will be using equipment at the same time. If you are a one-person shop then putting the drill press, spindle sander, band saw, scroll saw and lathe on one circuit may not be a problem because it is very unlikely they would be on at the same time. However, if two of you share the shop, make sure the circuit will handle whatever equipment is used simultaneously.
If you find that the number of circuits is more than the present panel will handle, an upgrade in this area may be needed as well. Sound expensive? It is, but you should consider electricity as a very important tool. Without it, woodworking becomes very labor intensive and may not be possible. If you skimp here and have only two plugs in the shop so you can unplug one machine to plug in the next one, you know what will happen. Sooner or later you will use undersized extension cords to plug into a multi-outlet gizmo that allows you to harness the whole shop into one circuit. This eventually overloads the circuits causing a fire hazard or ruins the motor on a power tool, which you will then have to replace. Do it right the first time.
If you do not feel competent enough to do your own electrical work, hire a qualified electrician. Go over what you plan to do in the shop. They may have a few ideas you never thought of.
Put the plugs at least 1.3 meters above the floor. This allows you to lean a sheet of plywood against the wall and still find the plug.
Run all your wires on the surface of the wall using conduit or armored cable. This makes adding or moving a plug a very easy operation. Also, if you outgrow the basement shop and build one in the backyard, you can take your electrical plugs and boxes with you instead of leaving them buried in the walls.
Make plans for tasks lighting at tools that are used for detail work such as the scroll saw and lathe.
You may want to wire the shop through a main shut off located near the door. You can then shut off all the power to the shop with one switch. You don’t have to worry about leaving a fan, compressor or soldering gun on. It can also be a very effective safety device to prevent unauthorized use of tools.