new shop electrical questions

[mark espinosa]

Hi All
I have a 19 x 29 shop in the building process that attaches to a two car garage. I have a couple of questions pertaining to receptacles and lighting.
I'm installing 10 quad receptacles, 20 amp. I'm having problems deciding on other standalone circuits as I haven’t bought any equipment. This is a residence so I only have a 200 amp single phase from the city. I plan on having a cabinet saw, a 15" plane, 8" jointer, band saw pretty much your std shop. I think these are the heavy current drawers. So should I put in 3 30 amp circuits or ? I doubt since I’m the only working in this shop I will be working 2 of these machines at the same time.
Also I have laid out what I think is adequate lighting. I have qty 8 four ft T8 fluorescents’. It seems that there will be dead spots and I want to put more but not sure I'm over killing this one. Any help appreciated.
Thanks

[Harlan Coverdale]

Another couple potential heavy current pullers are the dust collector and compressor, which can both have 5hp motors. Right now my compressor is my heaviest load, on its own 40 amp 220v circuit. My other 220v tools are all 2 hp or below and I only run one at a time, so they are all on one of a couple 20 amp circuits. I've also got four 20 amp 110v circuits in the mix for all the other stuff, including my DC.

[John Coloccia]

What I ended up doing was wiring my hole shop with 10AWG wire. That won't fit in those stupid stab connector outlets, by the way. Anyhow, anytime I want a 220 outlet somewhere, all I have to do is change the plug, terminate inside the box to a ganged 220 breaker, and I'm done. the 10AWG is good to 30A in my application.

So that's something worth considering.

[Sam Layton]

Hi Mark,

First of all, welcome to the Creek.

I also have a 200 amp service for my house. I installed a 100 amp sub panel in my shop. I installed 110 duplex receptacles every four feet around my shop (12 Gage wire, 20 amp circuit). I then installed 220 amp twist lock receptacles every four feet around my shop (12 Gage wire 20 circuit, I should have run 10 Gage wire for this one for possible future upgrades). I installed 110 duplex receptacles in four locations on the ceiling. I have pull down reel cords attached to two of them.

All of the above have several receptacles on a circuit. I installed dedicated circuits for my table saw-30amp, jointer-30 amp, planer-20amp, air compressor 30-amp, dust collector-30 amp, drum sander-30amp, AC-20amp.

The 100 amp sub in your shop is good. When my tablesaw is on, 5 HP motor, my dust collector is on, 3 HP motor, my AC may be on, my 5 HP compressor sometimes comes on, and sometimes I need to touch something up on the jointer 5 HP while everything is on. I have never had a problem. The 100 amps covers it all.

Don't forget about air...

Sam

[Bob Coleman]

I have a 20x23 garage turned shop (with a 3x9 closet taking out a chunk of lighted area)

I put in 6 8 ft T8s and 2 4 ft T8s, 4 on each half of the shop. See the attached for a rough sketch. I don't have any dead spots. I have them on two circuits that split the shop in half. If I leave one side off that side is pretty dark. It seems like overkill every time I turn them on, but while working I wouldn't want less.

[Prashun Patel]

Recall that at 220v, machinery actually draws less current than at 110v.

If it were me, for each 30A/220v ckt you were thinking to run, I'd run 2x 20a/220v circuits. The only time I'd run 30A is if one machine demanded it.

I learned during my installation that having 12ga throughout makes it easier to reconfigure and is considerably cheaper and easier to run.

Definitely put yr DC on a separate ckt from the other tools.

[Dave MacArthur]

I did my whole 3 car garage. As above, about the same recommendations:
100A sub panel, use one with a main-breaker you can use as master on/off
7-8 circuits
12 ga wire for 110v and 220V circuits up to 20A
10ga wire for 30A 220v, and I WOULD RUN 3 OF THEM.
--- you can always use the 10ga circuits for 20A stuff, but not vice versa.
--- I never imagined getting a 5HP saw, my 3HP Powermatic 66 was enough... then I got a 5HP saw stop ICS. I never imagined getting above a 3HP band saw, I lusted after the grizzly G0514x2.. then I got a 5HP Agazzani. I never thought I'd get more than a 3HP Dust Collector/Cyclone... then I got a 5HP Pro2000 from Oneida. My point is, all the planned stuff was good on 20A circuits on 12 ga, but now I am sweating it on my 5HP stuff, with temperature and conduit stuffing de-ratings I'm not really good for 5HP amps if inspected. Run at least 3 circuits of 10 ga.
Lighting--put it on two separate circuits! On their own with nothing else on them (no receptacles) so if a circuit blows while running some tool, your lights don't go out.
GFCI-- all circuits above grade in a garage or exterior have to be GFCI protected... with some execptions listed in the NEC, and probably implemented by your local city code. Protect your 110V receptacle runs with a GFCI plug on the first one. If you have a run of 220v plugs, do the same. However, usually circuits with one receptacle and a dedicated machine not easily moved don't have to be GFCI protected. Therefore, table saw, dust collector, etc., this is an area to check with your inspector so your chosen plugs and "dedicatedness" of the receptacle is accepted.

Dust Collector circuit
Air Filter circuit (I also use this for a ceiling quad with retractable pull-downs)
Air Compressor circuit


Here's my wiring diagram that got me 99% of the way through my permit/inspection process, and allowed inspector/permitter to tell me what he wanted additionally (ground via pigtails, not chained):

http://www.sawmillcreek.org/attachme...6&d=1282782550

Also, here's a good thread on the subject that's similar to yours:
http://www.sawmillcreek.org/showthread.php?t=146473

[mark espinosa]

Thanks Harlan This is good I will need to go over my list and make it a more complete list of items that are listed in this post and others below. Wow you have quite a compressor. Mine only needs a 15amp std circuit.

[mark espinosa]

Thanks Sam I have added these item ratings to a spreadsheet I've started. Might be helpful to someone in the future. I did forget to mention that this shop is only a portion of the addition to my house, the rest of the house had new wiring and the electrician ended up putting a 100 Amp sub panel to cover all the additional new items (Air Conditioning and heating system, WhirlPool Bathtub, 4 rooms' lights and plugs. The AC took a 40 amp circuit alone and Tub took two seperate 15 amp circuits. What I don't know is can I put another 100 AMP subpanel in the shop...I don't believe I can.

[Sam Layton]

Hi Mark,

I just did a major remodel to my house including building my shop. I completely rewired my entire house. I installed a 200 amp main panel. I also installed a 100 amp sub panel next to the main panel. I installed a 100 amp sub panel in my garage, and 100 sub panel in my shop. My sub panels have 42 full size breaker spaces each. I also have a spa, I think 60 amp, two electric ovens 40 amps each, I think, I don't remember, AC, don't remember how many amps. My kitchen has 10 circuits alone.

I like running dedicated circuits, and/or not putting much on a circuit. So it takes more breakers, and more space in the panel. My kitchen was 10 circuits (by code) alone.

All of my electrical was permitted and inspected. The inspector said that my 3 sub panels were no problem, everything will not be on at once. I have never had a problem or a circuit pop.

Also, on my lighting in the shop, I used 4 ft 4 tube florescent fixtures. They have two ballasts each. I wired them so I can have two tubes on, or 4 tubes on, (two switches) depending on my lighting needs. That way I always have complete coverage.

Sam

[Mike Cruz]

In a way, you are correct. You alone won't be drawing that much with only one machine at a time. However, if you have all the lights on, the planer, the radio, and...aw shucks, you alone can't draw that much. Just think about things that ARE running at the same time, not just machines. DC runs with every machine. AC/heat runs whenever it needs to. Lights are always on. Other than that, yes you are right, you don't run the TS, Planer, and jointer all at once.

[Ken Fitzgerald]

I wired my shop myself. It has it's own meter and 200 amp service panel. I have 3 lighting circuits....one for exterior lighting and 2 for interior lighting.

I wired 8 220 breakers each feeding a single 220 outlet. 3 outlets down each long wall of the shop and 2 across the short wall south end. The North end of my shop has a 10' garage door and a 36" walk through door and no 220 outlets. All the 220 circuits were wired using 10 gauge copper and I can go to 30 amps if necessary.

I have 5 110 circuits feeding outlets. 1 circuit feeds 110 circuits in the ceiling. The other 4 feed outlets in the walls. No 2 consecutive outlets are fed by the same breaker. Yet, 2 circuits and breakers feed 1 long wall and 1/2 of the short South wall. There are 110 boxes every 48" down each wall. They are 52" above the floor so that sheet goods can be leaned against the wall without blocking use of the outlets and they are above the standard work bench height for ease of use.

I left open 1 220 circuit capable of 60 amps in case I decide to learn to weld and buy a welder. The service panel is located between the 2 doors in the North wall of my shop and the plywood is held on with decorative washers and screws. A few minutes with a screw gun and I can have the plywood off and wire an outlet into that wall for the welder. I could then raise the garage door, move the welder outside the door and weld.

[Nick Walter]

Mike,

I wish I would have used ENT on my shop for outlets. It is a non metallic flexible tubing. In concept it is comparable to EMT conduit but flexible so that it is easy to install and requires no special tools to install. It will probably add $200 to the cost of the project but it will allow you to change circuits around later. Most big box stores carry it. It is usually blue or yellow.

[Joe A Faulkner]

What I ended up doing was wiring my hole shop with 10AWG wire. That won't fit in those stupid stab connector outlets, by the way. Anyhow, anytime I want a 220 outlet somewhere, all I have to do is change the plug, terminate inside the box to a ganged 220 breaker, and I'm done. the 10AWG is good to 30A in my application.

So that's something worth considering.

+1 for John's suggestion. The 10 gauge wire will be more expensive, but once in place, you can easily expand to 30A if needed. In my situation, I decided to run 12 gauge for my 110 outlets and 10 gauge for 220.

[Thomas Canfield]

Mark,

You said that the shop is running off the 200 amp house supply. When you add up all the shop load you need to also look at the house combined load against the 200 amp service. You don't want to trip the main and turn off the house. I have electric AC, dryer,washer, stove top & oven, and dish washer plus general lights and other loads that can all be running at the same time. I expect that the 200 amp would not be adequate for much shop load addition. My shop is on a separate meter with 200 amp service. I made the mistake of only running 2 - 30 A 220v circuits and ended up with a 2 HP dust collector, 2 HP Air compressor, 2 HP jointer, and then also converted my 1 1/2 HP table saw to 220. My solution was to use one circuit for the 2 HP dust collector changing to 20 A breaker, and then using the other 30 A circuit to a mini panel with 3 - 20 amp breakers for the saw, compressor, and lathe/jointer since they usually run 8 amps each or less and only 2 would run at any time together, one being the compressor, and I plug in either the lathe or jointer to use.