I need some help here! I’m trying to get going on the shop in my two car garage.
I need to size the wire and sub panel for the machines, lighting, and heating/cooling.
My shop is 24′ X 24′ X 11′ high with two 7′ X 10′ garage doors facing west. I’m going to replace the doors with steel insulated ones soon.
Is there a resource for how much lighting I will need?
As far as the machines are concerned I will need enough power for a 1 1/2- 2 hp. dust collector, a 1 1/2-2 hp. machine (like a table saw), a small blower or vacuum, and various battery chargers radio and the like at the same time.
This is a one man shop so I’ll be only running one machine at a time. I need to add these up so I can size the power accordingly. I’ll get help from a few people that know more about electricity but I need to give them a number for the overall requirements. Thanks in advance, David
Replies
"This is a one man shop so I'll be only running one machine at a time."
One machine at a time.....that's what I do too. For example, I use my router (full 15 amps of 110) to shape boards.
While it's running, there are also lights on (most of another 15 amp/110v circuit).
In order to keep the summer humidity from affecting the wood, there is a window air conditioner (probably 7 or 8 amps of 110).
And to keep the beads of sweat from dripping onto the work, there's a breeze box fan (maybe another 2 amps). Note that if the air conditioer and fan weren't running, I'd probably be running the space heaters, which take about the same current supply.
And I haven't included the radio, or all of those battery chargers, or an air cleaner, which I hope will be my next purchase.
So you see that one "machine" actually requires three full circuits (15A/110V) -- maybe even more.
I'm glad that when I built my shop, I ran a 60amp/220v subpanel. I still have lots of available power.
My suggestion to you is to install the largest subpanel you can afford. There will never be a problem if you don't use all of it. But if you install something smaller, and need more than it has, you'll be out of luck.
When I talk to electricians they want to know how much power I'll need. If I do it by the book I have to add all of them up and then throw in a fudge factor.
Wasn't there a thread about lighting needs recently? I want really good lighting.
I bought a 125 amp sub panel recently for the shop. Ya think it's to big. I don't have to fill it up. By code I should size the wire for 125 amp because someone could fill it up later. I plan to install a cutoff in the basement near the main and then run the wire over to the garage sub panel.
David, will your DC and tablesaw (either or both) run on 220?? If they will, IMHO you should use them on 220 and that will free up amps for other uses. Most machines "use up" about half the number of amps on 220 than they do on 110 (more precisely, 230 vs. 115).
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
They will both be 220 and any big machines I get will be too. Thanks for the input.
David here is a general rule that I go by when setting up shops, I move around alot with work so I do this every two or three years. I run one 110V line that will only power the ceiling lights. That way if I blow a fuse I don't lose shop lights, this is a must if you are running tools with a larger cutter head spinning at several thousand RPM's. Second I run two or three 110V lines for wall outlets that will power chargers, radio, compressor, etc. I try to plan out the layout so that I don't have one line supplying one area of my shop that will be running several items all at once ie the compressor kicks in while I am running the lathe. I will also label each outlet with the a number so that I know what run I am pluging into and and what is already on it. I will run two 220V lines for bigger shop tools. My DC has its own line as it is always running when any of the other shop tools are being used. The table saw, jointer, bandsaw, thickness planer etc all get plugged in the other 220V line as I have no figure out a way to use two of them at once yet, but if I do I will be sure to add another line in. I also try to place my 220V lines in the ceiling that way the cords drop down and are not under foot and some fool really has to try hard to reach up 9' to the ceiling to try and plug something in.
So in short you should need:
1 - 110V line for lights
3 - 110V line for shop tools
2 - 220V line for bigger tools
With that said if you can find a 100AMP panel you will be laughing. I know alot of new homes here are going with 200AMP services and 100 AMP boxs can be had for cheap if you look in the right spots.
Scott C. Frankland
"This all could have been prevented if their parents had just used birth control"
Scott, that was an excellent post, which I have duly printed out for future reference. forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
I agree. Run separate circuits for the lights. You can even split them up too if you want. Just look at the lights you plan to install (or the ones you have already) and add up the total. This will give you an idea of how big the circuit breakers need to be. Remember too size the breaker big enough. The lights should add up to no more than 80% of the breaker size (20 amp breaker means 16 amps worth of lights). Your tools that have induction motors may be able to be rewired for 240 volts. This is a good idea. My contractor saw can be wired for either (delta). look at the motors nameplate and it will tell you how much current it draws at what voltage and how it can be wired. Have someone qualified do it for you.
I just completed my new shop in the spring and I used double tube 8' high output flourescent bulbs at 110 watts per bulb and boy did that light up the shop. My shop is 24' x 30' with a vaulted ceiling and have 6 double fixtures on each side of the shop. I found a article in FWW on lighting requirements that I found very useful. On your power question I had Duke Power to put in a new 200 amp service free of charge to give me any and all future needs covered. Check with your local power provider for a up grade.
I submitted my electric needs to a friend yesterday for a recomendation on wiring. He saw 110 watts per bulb and was sceptical. Do I need that high of wattage per bulb? I'm thinking of the cost for the bulbs down the line. I'm going to check in town about cost for bulbs and availability. Thanks!
The fixtures where $50.00 each and the bulbs $6.00 each. The older you get the more lite you need to see to do your work . Your very high ceilings are going to work against you in getting usable lite to the top of your equipment and table tops . Do a seach in archives for the lighting article form a few years back on lighting.
There's an electrical contractor/ supplier in town that I trust. I'm going to have a visit with him. Anyway I've gotten the power for them and that's where I need to start. I'll hear back from the electrician soon. Off hand he thought 125 amp sub panel was cutting it close. I think the heating and air conditioning is what put close to or over.
I used to have my garage shop breaker box connected to the house main breaker box via a 220 circuit breaker. When both house AC's were running, the clothes dryer, etc, etc, along with my shop tools, I noticed that the house main breaker switch was getting very hot.
What I did was to install a 100 amp disconnect box beside the house panel and wire it directly to my side of the electric meter. The other side of the disconnect box goes to the 100 amp breaker box in the shop. You will have to call the power company to get them to allow you entry to the meter. If you live in an incorporated area then probably only a licensed electrician will be allowed entry. I also drove a 8' ground rod out by the shop.
I have five 110V and two 220V circuits in the shop. Four 110V for tools and 1 for lightning. I used #12 wire for the 110V circuits and #10 for the 220V. I have 20 amp breakers on the 110V lines and a 30A on the 220V lines.
By the way, if your using 15A on a #14 wire there will be about 25millivolt drop per foot of wire. Or, 0.5 volt for a 20 foot line. That equates to roughly 7.5 watts of lost energy. For #12 wire it would be about 16millivolt drop per foot of wire. See attached pic.
PlaneWood by Mike_in_Katy (maker of fine sawdust!)
PlaneWood
I can't help you with wiring but I have a 22 x 22' garage shop with six, two-bulb 48" florescents. Walls are white, floor is grey.
How much light you need depends on how reflective or not the interior surfaces are. I had one whole wall with brown peg board that sucked up light like a black hole. When I took most of it down and painted the rest white, it made a big difference.
But even with six double fixtures, I still don't have enough light. I added two 100 watt halogen floods on the ceiling just for special occasions -- like when doing layout and finishing.
Be sure to get the lighting centered over each major work area, especially bench and table saw, otherwise, you get shadows that are very aggravating.
I submitted a list of electric needs to a friend yesterday so he could recomend a plan for the wiring. I told him I would put 8 eight foot doulble flourecent fixtures in the shop. I'll probably switch them so I have the option of not having them all on. If I have trouble in higher usage areas I'll supliment with task lighting. The walls are white allready but I might paint it again with a brighter white before I start putting stuff on the walls. I think that should cover it. Thanks!
David, you might want to consider using 4' fixtures, double the number, rather than 8' The bulbs for 4' fixtures are, I think, easier to find in bulk packages at a discount than the 8', and are easier to install and probably cheaper per foot. We had a thread a couple months ago about lighting, and this specific topic came up.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Good idea! I'll do it. Makes sense now that I think about it.
Don't know how much you want to read about lighting, but here's the shortcut for the Fluorescent Lighting thread:
http://forums.taunton.com/tp-knots/messages?msg=12490.1forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
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