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Garage finish

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  • Garage finish


    I had a new garage built last year and am currently finishing it. It will be used primarily as my woodworking shop (but may park my wife's car occasionally!).

    So here's my question:

    I had a subpanel with 60amp service run out there. I have run seven (7) circuits;

    2 lighting circuits
    1 20amp 12/2 circuit with the garage door on it and 3 outlets
    2 single outlet dedicated 20amp 12/2 circuits
    2 4 outlet 15amp 14/2 circuits

    Enough? Overkill? Not enough?

    I will be running a table saw, miter saw, jointer, band saw, drill press (all Ridgid models), a small air compressor as well as various hand tools. At some point soon I'd like to add a mid-sized dust collector.

    Should I perhaps run a 240 circuit for the dust collector?

    Also, I can't find any wattages on any of the stationary tools. Any idea how to find those so I'm not blowing circuits all the time?

    Thanks for your input!

  • #2

    A 220 line, not 240... sorry!


    • #3
      I'm not an electrician, but I am a tool user. I have three 110 duplex outlets on the same GFCI 15a circuit and one 110 duplex on the same 20a circuit as my garage door. One separate light circuit. Wish I had more and don't have the bandsaw or joiner, but I make do. The locations of the outlets and the amperage greatly limit my options for future tools at this point. I make do but use a lot of hand tools (hand planes, etc). However, a couple observations:

      If you run a 220v circuit, you may be able to put more on it than your DC. For instance, my Ridgid TS3650 saw can be changed to 220 very easily. It pulls 13 amp at 110 but only 7.5 at 220v. I think the joiner and maybe some of the others can be changed as well. If you are unsure how to do it, have the electrician that runs the 220 v circuit change them for you. This may require a higher amp 220v circuit than you originally plan, but does free up 110 outlets for sanders, drills, biscuit cutters, battery chargers for all those new 24vLi tools,etc.
      The formula for watts is: Watts = Volts x Amps. So the saw listed above would be 110v x 13 amps = 1430 watts (1.43 kilowatts)
      To figure out what you will need, figure out how many tools you'll be running at the same time. The bigger ones probably won't be operating at the same time unless you have someone else working with you. However, things like a dust collector, shop vac as an alternate, air compressor, all may be running in conjunction with the other tools. I mention the air compressor because it may decide to cycle and kick on while something else is running, Altho the normal running amperage draw of several tools may allow them to run at the same time, the surge of the motor starting may overload the circuit.
      The reason I mention this is because my saw pulls 13 amps, and my shop vac pulls 7. Should be okay on a 20 amp circuit. However, If the vac filter is dirty so its working harder (pulling more amps). the surge voltage of starting the saw could overload the circuit and pop the breaker.
      Also, you may want to consider that future tools may pull more power. Routers used to pull 5 - 7 amps. Some of the newer ones (gotta have more power to drive those 1/2" shank bits) pull close to 15.
      Sorry to confuse the issue, but these are some things to help you plan, and its info the sparkies on the site can use to better advise you. They can give you the limitations of your current set-up and advice on what and how to add if necessary.

      Practicing at practical wood working


      • #4
        It is always a interesting calculation to determine the duty cycle of your circuits in order to check your expected loads and balance your circuits. Probably the simpliest way is to determine your maximum expected load. Which could include all lights on (assume 100w bulbs or about 1 amp per light), one major tool running (assume 15 amps), the future dust collection system (assume 15 amps), and then someone opens the garage door (probably 10 amps). Unless you have alot of lights, or some other continuous loads (like an electric heater), or you are plannign to run multiple tools at once, your 60 amp service should probably be good.


        • #5
          well, if your dust collector is 240-volt 1 horsepower, you are looking at something in the region of 4 amps .. [and it is 240 volts and 120 volts, some places it is 125/250 or 130/guess what?]

          a garage door openeer is probably 1/2 hp max - so maybe 6 amps max at 120.

          Any tool that requires 15 amps to run needs its own 20-amp circuit.
          You could put a water heater out there and not bother your 60-amp panel a bit!
          Licensed Philadelphia electrician
          Philadelphia emergency lighting certification


          • #6
            Most contractor's stationary table saws anymore have 1 - 2 HP motors and many are not high efficency designed. Because most are 3450 (approx) RPM they require a good bit of starting current. To be safe (not keep tripping circuit breaker) I would try to wire the motor for 240 Volts rather than 120 Volts. This requires that the switch be 2 poles so as to break both hot sides. I would have an electrician install a NEMA 6-20 receptacle that's wired to a 20 Amp. 240 Volt circuit. Now if you have a cabinet saw with a 3 or 5 HP motor, you'll need a minimum of a 30 Amp. 240 Volt circuit. In such a case it would do well to install a low voltage push button switch, control transformer and a proper magnetic starter based on the motor. Something many of us forget is the starting current which is several times what the normal running current of a motor is. We need to think about Voltage drop during startup. As for a dust collector, the electrical requirements will be based on the motor used to power it. A small 1/2 HP is very different from a larger, powerful 5 HP model as I'm sure most of us here know. If you can do so, I would try to have several 20 Amp. 120 Volt circuits with single 5-20 receptacles, and 2 or or more 20 Amp. 240 Volt circuits with 6-20 Receptacles and also 1 circuit that's 30 or maybe 50 Amp. 240 Volt with a 6-30 or 6-50 receptacle. If you ever get an arc welder, you'll be glad to have a 50 Amp. 240 circuit setup. In addition, you could rig up a heavy duty electric heater to plug into that receptacle. I'm talking about a serious heater and not the norm for home use.

            My point is that you really would have to go totally crazy to overkill the electricals in a garage workshop and especially one that's a 2 car or larger size. If your woodworking becomes serious, you'll be having all kinds of electrical loads and what a PITA if you have to constantly unplug one machine so you can run another.

            Something many of us never think about is that if you work at night, please think about installing an emergency light in your shop. It can get very dangerous real fast when you have a power failure or trip the circuit breaker for your lighting circuit. They aren't that much $$$ and can be your little buddy when needed. If your garage is cold or damp, you'll need to look into one that can deal with such. In a dry and climate controled shop that won't be an issue.

            Finally, you should considder installing small emergency lights in your house to light up stairs and main hallways. I know this may seem crazy, but when you need them, you'll be glad to have them.

            Please everyone Think SAFETY FIRST


            • #7
              emergency lighting is a great idea
              Licensed Philadelphia electrician
              Philadelphia emergency lighting certification


              • #8

                I'm glad you like the idea about emergency lighting. I have small emergy lighting 3 units in my house to so that stairs and halls are illuminated during power failures. In the basement, I made use of 2 remote heads. My garage isn't my shop so I didn't worry about that. I do keep several flashlights in clips that mount to the wall handy and have them all over the place. Call me crazy, but in my area we have loads of power failures. I'm not an electrician, but I happen to know a few good ones. What am I is TOTALLY INSANE and I know it.

                Part 2: RW Do you get into doing installation of residential standby generators or inverter systems? It's a growing business with some nice $$$ in it. The main customers are the YUPIE types with all kinds of $$$ to their name and loads of fancy electronic equipment. The others are older people that want the safety and security of having one.
                Last edited by Woussko; 01-14-2007, 02:50 PM.


                • #9
                  no, I have made motions in that direction, but I suffer here from the same problem I have everywhere else in my field.

                  stolen comment: "Low price guarantee!" [I guarantee I do not have the lowest price .... just the best work..]

                  I will always be underutilized....because people are stupid and think a low price means a bargain ...
                  Licensed Philadelphia electrician
                  Philadelphia emergency lighting certification


                  • #10

                    I know that one only too well. This my own saying to them. Quality only costs more until put to good use. Then it cost you far less over the long run. People in my area that make $250,000 per year being of the YUP type howl about $15 battery powered smoke detectors. FOOLS I can't wait for our new county law that requires CO detectors if you want to have home owner's insurance. They just can't get the idea that such is very cheap life insurance. Then another thing that gets me is that they all run around in nice new $50K plus cars, but refuse to have the oil changed. In a short time their car is scrap metal, and they *&&^$^ that it's a pile of junk.

                    I want to see safety code enforcement in movie theatres. EXIT signs that are totally dark, missing fire extinguishers, emergency lights with the heads busted off and no pilot light on and more. It sure looks like the problem is that big corp. $$$ payoffs (bribery) keep them from being shut down.


                    • #11
                      Re: Garage finish

                      It is unnecessary to resort to bribery when incompetence serves to accomplish the same ends admirably.
                      Licensed Philadelphia electrician
                      Philadelphia emergency lighting certification