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Forum topic by g1hopper posted 11-12-2013 07:40 PM 1537 views 1 time favorited 33 replies Add to Favorites Watch
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65 posts in 3481 days

11-12-2013 07:40 PM

Topic tags/keywords: question shop electrical

I am having a new home built and am trying to make sure I think of what I need for the shop are. The new shop will be part of an attached garage. Shop dedicated space will be about 525 sq. ft. I am considering having an electrical sub panel ran into the shop area.

Do you think this is a good idea?

How many amps should the sub panel be? The estimate I was given was for 60 amps or 100amps.

Current I have an electric heater that runs on 240v. I have to have a gas heater at the new place, but may still need an outlet for this one for a short time.
I hope to upgrade my table saw and maybe dust collector someday to 240v also.
I would like to hear your thoughts. Maybe anything else I should be thinking about while I am at it.

-- Steve, Omaha, NE

33 replies so far

View bigblockyeti's profile


5112 posts in 1717 days

#1 posted 11-12-2013 07:47 PM

Go with 100 amp, if you find yourself with a large planer working hard and a big dust collector working with it you could be very close to 60 amps with just those two, not to mention lighting, and everything else that’s in the shop. It’s a little more money now, or a whole lot later on.

View 489tad's profile (online now)


3363 posts in 3008 days

#2 posted 11-12-2013 07:47 PM

Its a good idea if there’s not enough room in the main. Easier to do it now. One thing I did in the event I ever converted to 220 was to have the proper gage wire installed. I never did the switch. I hope this helps.

-- Dan, Naperville IL, I.G.N.

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Monte Pittman

29224 posts in 2334 days

#3 posted 11-12-2013 07:49 PM

Always go bigger in the beginning. You will never hate yourself for it.

-- Nature created it, I just assemble it.

View grazer's profile


3 posts in 2511 days

#4 posted 11-12-2013 07:50 PM

100 amps. Better too much than too little and not a lot more money to accomplish in the building phase unless you are a long distance from the main panel. The reality is that you are never going to be utilizing all of the big amp draw equipment at once since you are not a production shop. However, what man doesn’t want more?

View Wes1952's profile


1 post in 1653 days

#5 posted 11-12-2013 07:51 PM

Yes add the sub panel. You’ll find it money well spent and a convenience that will pay you back when you make changes and upgrades later.

View crank49's profile


4030 posts in 2967 days

#6 posted 11-12-2013 08:05 PM

Yes to the sub-panel.
I am just starting to do the same thing.
Going with 100 amp because I also weld and I want enough juice to run an air conditioner.
Why limit your future?

View g1hopper's profile


65 posts in 3481 days

#7 posted 11-12-2013 09:45 PM

Thanks everyone, that is what I thought you would all say.

-- Steve, Omaha, NE

View dhazelton's profile


2767 posts in 2293 days

#8 posted 11-12-2013 09:54 PM

Whatever you are using for heat I would see if you can add the garage as it’s own zone now. May save you money down the road and be more comfortable vs. a propane space heater.

View Jeremy Greiner's profile

Jeremy Greiner

568 posts in 2768 days

#9 posted 11-12-2013 10:06 PM

I just had a subpanel added to my basement and I got 100amp, as everyone before the cost difference shouldn’t be a huge amount, and it’ll be way more expensive to upgrade to 100amp should you ever need too later.


-- Easy to use end grain cutting board designer:

View Todd's profile


398 posts in 1673 days

#10 posted 11-12-2013 11:24 PM

Subpanel – absolutely! If you have more than 6 circuits you’ll need a main breaker.
I have 60 AMP service to mine and my shop is 16×24. I have all the tools I need and haven’t run out of juice yet; however, 100 AMP would probably be a good idea. Definitely if you ever weld.

I wired my own shop. I made sure to put separate circuits for my compressor and DC. That way I can run my DC, a power tool on another circuit, and not have to worry about my compressor cycling while all of this is going on. Maybe slight overkill but I wired it myself and I had a main breaker so I could put as many circuits as I wanted.

Since your shop is attached you’ll likely have to use drywall. I used OSB in my detached shop so I could mount most anything on my walls without worrying about studs. The added bonus is I don’t have to worry about punching holes in the walls accidentally.

-- Todd, Huntsville, AL

View mahdee's profile


3883 posts in 1764 days

#11 posted 11-13-2013 12:01 AM

Yes, for sure 100 AMPS or better. Allow at least two 240 Volt runs as they are more efficient than 110/120. You can save a lot of money using a 240 volt heather (forced air) than a 120 one.


View DocSavage45's profile


8549 posts in 2839 days

#12 posted 11-13-2013 12:51 AM

Is the wiring in conduit? Not only a big panel but make sure it will accommodate the maximum load you intend to run. Make sure the draw is from both sides. Use copper not aluminum. ground faults as well.

Will you run a big dust collector and a big cabinet saw?

-- Cau Haus Designs, Thomas J. Tieffenbacher

View Whiskers's profile


389 posts in 2023 days

#13 posted 11-13-2013 04:59 AM

Ground fault outlets are not supposed to be used on circuits that use large electric motors from what I had read, electric motors supposedly kill them.

View darthford's profile


601 posts in 1920 days

#14 posted 11-13-2013 05:55 AM

I just had a house built last year, I really wasn’t planning to get back into woodworking at the time so I paid no attention to electrical in my 3 car garage in prep for this. Here’s my list…

Go repeatedly cuff your electrician sub in the head until he’s paying attention and taking notes then…

1. Tell him you want to conserve breaker slots for later use, I found they will waste 15 amp slots on short runs that no way will ever pull 15 amps. They focus on what easiest and quickest for them to get the job done. They will also run whacky illogical runs, they have no master plan, they give no thought to laying things out before they begin, and they don’t keep track of what breaker feeds what and mark it accurately. I’m talking the general runs, obviously they do mark the big breakers correctly for oven, drier, heat pump etc.

2. There are some 15/30/15 Square D breakers that give you two 15 amp 120v breakers plus one 30 amp 240 volt breaker in the same space a single 30 amp 240 volt breaker takes up. They cost more but free up 2 breaker slots.

3. Consider your dust collector, I have this 1.5 HP Grizzly G0703 Cyclone that pulls over 60 amps on start up. The breaker will usually take that surge without tripping but I found it would still trip a 20 amp 240 volt so I ended up having a dedicated 30 amp 240 receptacle for it since it would always be running with a machine.

4. I needed another 30 amp 240 receptacle for the table saw. My bandsaw and jointer both require a 20 amp 240 volt breaker. Some 20 amp 120 volt for other tools. Factor in shop lights you can never have enough. I use 6 bulb fixtures with 6 ‘daylight’ bulbs, awesome shop lights, I have 5 in my 3 car garage already and really could use 2-3 more. When you start adding up what these fixtures pull that will be a dedicated circuit.

5. In our area they inset the breaker panel into the wall so once its closed up with sheet rock there’s no easy way to run more wire. I found I wanted to run some stuff outside the wall in conduit, but how do you get from the panel inside the wall to the surface in a way that’s code. I would consult your electrician on this. I like sturdy metal boxes screwed to studs for outlets not the flexo-matic plastic junk they use these days.

6. The electrician is likely to use the cheap 10 cent china receptacles, budget $100 to $200 more to opt for the higher quality throughout the house, that’s one of the dumbest things imo for the paltry increase in cost you can get a much better quality.

While I’m on that subject that’s true for the rest of the house. My cost to upgrade from the junk particle board cabinet boxes and drawers to 3/4 inch hardwood plywood boxes with maple dovetail drawers was only a few hundred dollars. The upgrade from knotty alder plywood panel doors to hickory with solid raised panel doors was another no brainer upgrade price wise it wasn’t that much. I did go with the plywood panel hickory doors in the baths due to the moisture. I added soft close on the kitchen drawers and doors.

Next was plumbing, the builder budgeted to install and I’m not kidding $50 China toilets. I upgraded to American Standard, they were a LOT more expensive like $250 each but worth it imo. The China builders grade toilets were junk. I didn’t go hog while elsewhere, upgraded the kitchen sink to black granite composite vs the builder grade cheap stainless, went with the builder standard round white sinks in the baths, upgraded the master faucets to mid grade and the other bath faucets above the $10 builder grade, yeah $10 that’s how much credit I got towards a better faucet.

Next was lighting, I was only given a $1,000 budget for lighting fixtures, I would have had to buy literally the cheapest China fixture for every location to stay within that budget. I ended up spending over $2,000. I didn’t buy the fanciest fixture available, just good solid tasteful choices of good value for the money. It really made a difference. The lighting budget was way under what it should have been.

Next was flooring, again the builder budgeted for builder grade 99 cents a sqft carpet, it was horrible though I did go with that in the 2nd, 3rd, and 4th bedrooms. It was so cheap I didn’t mind throwing it out later after some use. I upgraded the master and rest of the house carpet quite a bit. Go with a thicker pad also. They planned to use the snap together Pergo type flooring, I upgraded to 3/4 #2 knotty oak sanded and finished in place.

The only other upgrade was counter tops, the builder planned to use tile, I upgraded to slab granite throughout the house, its awesome.

Okay well that was quite a brain dump hope that helped.

View Charlie's profile


38 posts in 1708 days

#15 posted 11-13-2013 07:02 AM

It’s a misconception that a piece of equipment wired 220v is more efficient then 120v and will save a lot on electric bills. A 5000 watt heater will still consume the same amount of energy wired at 120v as it will wired 220v. The amount of efficiency would only be in the amount of resistance in the size and length of wire used. You wouldn’t see the cost savings in your electric bill in a lifetime. The real savings is the up front cost where you can use a smaller wire size at a higher voltage to do the same amount of work. Say going from a #10 wire to a #12.

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