Electrical Considerations

[elav]

I have a house that was built in the '50s with a 100 Amp service panel. The only real power I have in my two car garage are the light fixtures in the ceiling. When I want to run my air compressor I need to run an extension cord from the garage to a plug in the main bathroom - not good! So I've decided to upgrade the main panel to 200 Amp service and have a sub-panel run to the garage. My garage walls are just the studs so running the new electrical will be easy. What recommendations do people have as I might as well have the electricians do as much of the work as they can while they are here. My garage doors are solid (no windows) and there are no windows in my garage so I know that lighting is very important. Do people like industrial power strips (meaning hard wired) or just traditional boxes? What spacing and height do you recommend having the electrical boxes and should they be single or double boxes? Do people like having electrical boxes in the ceiling? I did this in my last house for the garage door openers and lights and they worked out very well. Any comments are appreciated!

 

[rockwithjason]

i like my outlets to be about waist high and about 6ft apart. if you have a work bench having a plug mold strip that spans the whole bench is nice. if you don't have an outlet for a garage door opener that would be a nice add. you can stub a few outlets out to the outside of the house too if you think you have a need. i personally would put a sub panel in the garage for future expansion. if you want a welder outlet or other equipment that would be good too. i like t8 florescent lights

 

[Gary S]

My simple recommendations.

All receptacle circuits are 20 amp.

15 amp circuits are adequate for lighting only

Put a receptacle every 6' along every wall and extra circuits over the work bench.

Wire for ceiling fans when wiring lights.

In addition to the receptacles every 6 feet on the walls, put in additional circuits for heavy use items like 120v compressors and air conditioners.

Put receptacles in the ceiling for garage door openers.

 

[Cyberbear]

In addition to the already offered advice, I'd suggest putting in lots of double boxes, they only cost a little more and it takes the same amount of labor to install as a single outlet box, more the better. Spare boxes can be used in the future when you need to up grade to equipment running on 240 volt. Surface mounted metal boxes and EMT allow you to add or change the layout as needed. If you can afford it, run a few extra circuits for future additions, it will cost less now than later.

 

[Torque1st]

I have a similar situation. I recently upgraded my 100A house panel to 200A service with a 200A 30/40 panel. I am running a 100A subfeed to a 150A main breaker 30 space garage panel. The breaker in the garage panel is just used as a local disconnect. I also have an existing 60A feed to a new 100A MB 20/20 panel in the basement workshop.

I wire 15A lighting circuits in each area with a dedicated fixture in each. Then I put double box outlets in the ceiling all around so I can install shop lights right where I need them. I can also change locations as my needs or layout changes. I use the pull-chain switches to shut off unnecessary lights to conserve energy.

I use double boxes whenever possible for 125V 20A circuit shop power outlets mounted 42 or 48" off the floor. Usually one circuit for each wall of the garage or shop area for easy labeling.

You will need dedicated circuits for the big power users, compressor, welder, saw, machine tools, etc.

Special items like a shop fridge, HVAC, door opener, ceiling fans, etc should have their own circuits.

Look into French cleats for mounting wall cabinets or equipment, etc. They allow cabinets to be mounted and moved anywhere as needed.

 

[2ManyProjects]

So I've decided to upgrade the main panel to 200 Amp service and have a sub-panel run to the garage. My garage walls are just the studs so running the new electrical will be easy. What recommendations do people have as I might as well have the electricians do as much of the work as they can while they are here.

Any 240V machines need their own specific solutions. Until you/we know exactly what those machines are (or will be), it's pointless to guess at it further.

For your general-purpose 120V outlets, my usual "recipe" will likely suffice: Put one double-gang box every 6-8 feet around the entire perimeter of the space, with each of the two duplexes in that box fed from a different breaker than the other one. In small shops (such as yours), two 20A circuits will normally handle the whole thing; in larger shops, split it up further as you see fit. Optionally, add a third circuit in the vicinity of the workbench, especially if you (will) have high-draw tools (bench grinder, drill press, etc.) in that area. Keep the bottom of the boxes at least 49-50 inches off the floor; you'll understand why the first time you try to store a 4x8 sheet of plywood, drywall, etc. And finally, note that at least in anything which might be considered a "residential garage", NEC now requires that ALL 120V outlets be GFCI protected.

For the general lighting, it largely depends on the specifics of the space (i.e., the dimensions, most notably including the ceiling height; the layout of the work areas; the interior finishing; & etc.) and what sort of work you will be doing in there. Typically, you'll want three switch loops: One for walk-through lighting, and two for the "Main" lighting. The lighting should be split between at least two separate circuits, so that if/when one trips (or must be shut down for maintenance), you're not left near-completely in the dark. At least the "walk-through" lights (and ideally, ALL of the lighting) should be controllable from EVERY possible entry point.

Your workbench and any permanently installed machinery will also require suitable task lighting. One or two outlets in the ceiling for such things as trouble lights on retractable cord reels is a reasonable idea. But otherwise, any fluorescent lighting should be hard-wired, so as to avoid the need for running it from (now NEC-mandated) GFCI-protected outlets, which is often a problematic combination.

If your overhead garage door(s) has/have torsion-type counterbalance springs (or can be retrofitted with such), then a side-mount opener such as the LiftMaster 8500 will make for a MUCH neater, cleaner installation, without a belt/chain track cluttering up the center of the ceiling:

http://www.liftmaster.com/lmcv2/productdetail/19724/liftmaster-products/

To be much more specific, we'd need to know more about the details of the space.

 

[Torque1st]

I made a lumber cart with a side set up for cutting panels to hold my sheet goods. It rolls around on lockable casters. I got real tired of moving sheets of 'stuff' to access things. No matter where you put that sheet for now it is always in the way later.

IIRC the NEC calls for two circuits in a box to be from a double breaker with a common trip.

Check with your local code admins to see what version of the NEC you are on and what requirements they have adopted or eliminated. There have been some 'questionable' or problematic requirements lately that have not been adopted by all authorities.

 

[sberry]

That opener looks great and the only thing I don't care for in a small shop is all the dual quads with 2 circuits and a lot of convoluted stuff side by side just in case etc. Its ok for Charles or Cary but you don't need it its not for everyone, one circuit to a box if possible.

Do you really need to run 2 electric heaters at the same time from that box?

I have been thru this a couple times and can tell you after the place is built you don't need it,,, hahaha I like the ,,, everything on one wall is on one, the other wall the other and a couple on the benches, one for tools and one for parasitic ****. Pretty easy to reach 2 for the occasion you actually need them and then are sure which is which.

Would leave an access point to the panel for simple addition or 2 if needed for future equipment. The whole place may not need to be piped, leave a simple 2 box raceway in a convenient place, change air comp, add wire. Adding a coup[le pcs of 10 to a box or 2, one for a comp and the other to a small welder etc.

 

[sberry]

Ideally would be to use the space for a while before rocking it. I like plug in lights also, I used to like not seeing cords etc but there gets to a point where convenience wins for me.

shops are slightly different than living quarters, I got ne place in corner where if you count 20 ft each way there is no real outlet for 40 ft of wall run. Got another place within 10 ft have 25 outlets. Needs change a little and its so cheap and easy to use a common power strip anymore. When I fist moved in needed that quad for a while till the rest of it got tailored, now have a circuit with nothing on it but 1 fixture that burnt out last week and need to replace and could just as easy reach another lightly used outlet.

 

[JoeFin]

Other then what has been mentioned by others - 1 outlet next to the garage door down low for the extension cord you plug in to take out into the driveway to work on your car/truck/boat

 

[sberry]

It needs an outlet there with a weather proof cover. In a garage it could feed a gfci in the building at that point and a recept thru for an outdoor.