How many cirrcuits/switches for my setup???

[scribble79]

I am in the process of running all the electrical for my new garage build, its a 24W x 26L X 22H. The ceiling height on the main level is 9'2". The attic/storage area is 7'6" at the highest point.

I am trying to determine how many circuits/switches I am going to need to run all the ligts on the main floor. I am currently looking at 15 4' fluorescent double tube lamps. ( I have them already on a steal and am going to use them until I can get the recommended conversion fixtures and LED bulbs) 2 double 4' tube Led over the work bench and some kind of light above the back door. I am running 12-2 for all my lights and outlets. The other thing is I am going to install double gang 20A outlets in all my receptacle setups. A friend suggested I split each of my double gang outlets to separate circuits in case one popped I could just swap plug to left or right and continue working.
I am attaching a crude Excel picture of my lighting layout(in red) and my outlets are shown by X's.

Please let me know your thoughts. I have 18 breakers left to play with in my panel.

 

[nadogail]

you might find that all your lights can be run from one 15 Amp circuit. it depends on the current draw. I would prefer that the lights be fed from two circuits, on separate phases for redundancy. My own shop with 4 fixtures has a switch for each fixture, but I generally have all of them on at the same time.

I over thought the lighting.

 

[ddawg16]

Do two ckts

One for the lights going horz and one for the others going vert.

You are going to have a LOT of light.....almost too much.
I would divide it up into zones...min of 4.
Front, Rear
Horz, vert.

A lot of times you are not going to need all of it. My garage is about the same size and I have 18 LED cans which is plenty.

On your outlets....I wouldn't do the 2 ckt per box. If what your doing blows on ckt...then it's going to blow the other one.
But do alternate. Mine are no more than 6' apart and 52" from the floor. That way a sheet of plywood up against the wall does not block an outlet.

My outlets are quads....but alternate ckts. So if I'm doing heavy loads...one load on one quad box, the other on the quad box 6' away.

 

[FMB4]

I'd skip the florescent tubes and go LED from the very start. Also take a look at some of the online electrical 'power calculators'. Then go with 15-20% higher than the minimum recommendations.

 

[Shiftless]

I agree that 15 double tube fixtures is overkill. Have you checked out the layout suggestions in the sticky linked here?

Light Fixture Layout Collections

Since I’ve spent a fair amount of time doing Light Fixture Layouts for GJ members, I figured I'd put them all in one thread as a general reference guide. I’ll start with the latest and add more as time permits. All Isoplots in footcandles and done at 30" workplane height (30" from the floor)...

www.garagejournal.com

Also, regarding 2 circuits in each box so you can keep working if you pop a breaker…
If you pop a 20 amp breaker while using a tool plugged into that receptacle, I’d guess that there is something wrong that you should address right away.

 

[scribble79]

Good Idea with the quads. I had so many shadows in my old garage that I used some lighting layouts found on here for my configuration and hope I don't have any shadow areas in my new area.

 

[Terry D]

I agree, if the fixtures you have now are a good quality for a LED retro fit, I would do it now and be done with it. Maybe have the single tube fixtures all come on with the fixture at the back door, have the double tube fixtures all come on together and a separate switch for the work bench lights. How many doors are you having, is there a need for 3-way switches. I would do quads at your workbench and have (2) 20 amp circuits for that, As far as the rest of the garage, I would have at least 2 circuits out there. All depends what you are plugging in

 

[sparky 1971]

One 20 amp circuit will be sufficient for the lights. Switch them however you want. Most people overthink the switching and wind up having to flip two or three switches to turn them on and off then wish everything came on with one switch since they always turn all the lights on anyway. As far as receptacle circuits, that depends on what you are going to have. If you are going to have a 120 volt air compressor, give it a circuit all by itself. They are notorious for kicking on at the same time the trigger is pulled on a miter saw or chop saw, resulting in a tripped breaker. Stationary power tools could get dedicated circuits, but in reality, you can only use one at a time. Maybe if there is a dust collection system you could dedicate that circuit also. I don't know about a shop vac and a miter saw running on the same circuit at the same time. I have five 120 circuits in my shop, nothing is dedicated and I have: table saw, miter saw, chop saw, and a drill press for the tools that don't move along with a ton of corded power tools. I only recall tripping a breaker one time, and that was when I tried using a 120 volt stick welder that I threw away.. There is only one quad receptacle, it's above my bench and I don't think I have ever had more than two things plugged in at once. There are probably 20 duplex receptacles, most have never been used. I do have three flexzilla retractable cord reels, one 25' and two 50' that I mostly use. My air compressor and welder are now 240 volt models so I don't have to take them into consideration. My shop is also wired in conduit, so if necessary, I can add circuits as needed, but I doubt that will ever be needed.

The bottom line to not make it more difficult than what it really is. You can get a ton of money wrapped up in a project that could be better spent on shop equipment.

This rambling has been nothing more than my opinion based on experience, which really doesn't amount much more than a pinch of ****.

 

[Shiftless]

I wholeheartedly agree with Sparky1971. His advice is worth a lot more than a pinch.

I’m glad I put workbench lighting in a separate circuit. I use that lighting way more often than general area lighting.

 

[scribble79]

I agree, if the fixtures you have now are a good quality for a LED retro fit, I would do it now and be done with it. Maybe have the single tube fixtures all come on with the fixture at the back door, have the double tube fixtures all come on together and a separate switch for the work bench lights. How many doors are you having, is there a need for 3-way switches. I would do quads at your workbench and have (2) 20 amp circuits for that, As far as the rest of the garage, I would have at least 2 circuits out there. All depends what you are plugging in

The fixtures I currently have are not convertible as the ballast are part of the tombstones on circuit boards and I don't think I can retro different tombstones in but I may still try. I am running a wood shop with all the tools a good woodshop requires: table saw, band saw, planer, jointer, dust collection, router, drill press, track saw. I will be doing 3 way switches at each door in and out of the garage. The garage has a 16 x 7 garage and a 36 man door. If I can run most of the lighting on 1-2 circuits and the bench lighting on another I think that will be the best option.

 

[Terry D]

The fixtures I currently have are not convertible as the ballast are part of the tombstones on circuit boards and I don't think I can retro different tombstones in but I may still try. I am running a wood shop with all the tools a good woodshop requires: table saw, band saw, planer, jointer, dust collection, router, drill press, track saw. I will be doing 3 way switches at each door in and out of the garage. The garage has a 16 x 7 garage and a 36 man door. If I can run most of the lighting on 1-2 circuits and the bench lighting on another I think that will be the best option.

I do recall your previous thread on the fixtures. I understand you getting a deal on them, but those are throw away fixtures. You cant even change a ballast on them. I would not even use them. If you put a quality fixture in there, you will not need so many of them. I just did a 24 x 30 shop. I used 9 RAB GUS LED fixtures, plenty of light. They are around 150.00 a fixture, so not cheap. But like Sparky1971 sais, keep it simple and spend the money on more important things. And I also agree, now that I know this is a woodworking shop. have them all come on together.

RAB GUS4-36NW/D10 36 Watt 4' LED GUS Surface Wrap - 4000K - 4,437 Lumens - 120-277V | PROLIGHTING

Save money with the RAB GUS4-36NW/D10, designed to deliver general ambient lighting for surface-mount ceiling, wall or pendant mount applications. Replaces traditional 2' linear fluorescent wraparound fixtures. Delivers 4,437 lumens of 4000K neutral white light. Order your GUS4-36NW/D10 today or...

www.prolighting.com

 

[sparky 1971]

Now that I know that you are wanting to use THOSE fixtures, my advice is to throw them away. Don't waste a ton of money running 18 circuits worth of 12 gauge wire. Use the savings to buy decent fixtures. Terry posted some good fixtures. I personally like the strip light shells with led tubes. If it were my shop, there would be three rows, each having two 8' and one four foot, butted up end to end for 20' total. One row right down the middle, and the other two rows each 4' off the sidewalls. You could put another over the bench, but I doubt it would be necessary. And turn them all on together.

EDIT: If you insist on using the junk lights that you got a deal on, use them in the attic. Save the unused fixtures to replace the ones you do use when they go bad, and they will.

EDIT #2: I didn't see the stairwell on my small screened tablet yesterday. The center row would only be two 8' fixtures which may have to be located a little off center depending on the location of the door opener.

 

[vwpieces]

Thats a lot of fluorescent lights to power all the time when in the shop of that size. And when you go LED you will need even less of them on. I would split by alternating power to every other light in some way. Something to consider.
And also think about where a car will be positioned that you will be working on with hood open. Position that light above the hood a foot or 2 ahead so the hood does not block it. Same with side lights above fenders, helps a lot. LED tubes that delete the ballast will also save more on electricity.

My shop is 25X50 bout 9.5 ft ceilings. I also have garage doors at each end that get used. Wanting a SW at each end at the door, I only have the center strip of lighting switched. All the other side rows of lights are on pull chain. And of the 6 lights down the center, 4 of those are pull chain too. The 2 center lights that are always on are 4 tube with a diffused cover and throw a good amount of light. I am good about turning lights on and off as needed, I pay the Bill. Everything is frosted LED tube, no ballasts in the fixtures. Clear un frosted tubes make you see lines of spots when you roll out from under a car looking up at them.

2 compressors, small 120V on its own breaker and is switched at the man door. Large compressor is 240V on its own.
I did all quad outlet boxes but the duplex are linked together, same breaker. I did alternate the outlet boxes to breakers down the walls. I also tapped into a couple outlets off the second floor because it was easy and the second floor is just storage.

Before I ran the 100A service there was only 6 lights in here, 3 upstairs, 3 down. 6 outlets upstairs and 4 down. Only 2 15A breakers.

 

[scribble79]

The lighting layout I pulled off the lighting layout pages on here for a 23x 27 shop. And I beleive the fixtures and bulbs that are recommended in the sticky are what was being recommended for that layout shown.

 

[vwpieces]

The middle rendering with the cars and better proportion brings things into perspective. Lighting layout should work well.
Curiosity, had to look up your lights. I agree with previous comments.

 

[scribble79]

I’m glad someone understands why I am doing the layout and quantity that I’m thinking. If I had new fixtures and the bulb budget trust me I’d be ordering the good lights but for the current time I’m going to stick with my fluorescent lights I have.

 

[sparky 1971]

I am in the process of running all the electrical for my new garage build, its a 24W x 26L X 22H. The ceiling height on the main level is 9'2". The attic/storage area is 7'6" at the highest point.

I am trying to determine how many circuits/switches I am going to need to run all the ligts on the main floor. I am currently looking at 15 4' fluorescent double tube lamps. ( I have them already on a steal and am going to use them until I can get the recommended conversion fixtures and LED bulbs) 2 double 4' tube Led over the work bench and some kind of light above the back door. I am running 12-2 for all my lights and outlets. The other thing is I am going to install double gang 20A outlets in all my receptacle setups. A friend suggested I split each of my double gang outlets to separate circuits in case one popped I could just swap plug to left or right and continue working.
I am attaching a crude Excel picture of my lighting layout(in red) and my outlets are shown by X's.

Please let me know your thoughts. I have 18 breakers left to play with in my panel.

I’m glad someone understands why I am doing the layout and quantity that I’m thinking. If I had new fixtures and the bulb budget trust me I’d be ordering the good lights but for the current time I’m going to stick with my fluorescent lights I have.

 

[FMB4]

Again, ditch the flors and go LED from the start. You are looking at wasting much more money trying to run those hopelessly outdated flors than what you think you'll save after you meet their wiring requirements. And again, make use of one of the many online electrical 'power calculators'.

 

[scribble79]

Ok so someone please tell me if my math is wrong. If I go with the fixture and bulbs listed to get to just the recommended 15 light assemblies it will cost me 675 plus shipping. All the fluorescent lights are already paid for and cost less than $75.00 with a case of new bulbs. I don’t think it will cost me that much to hook the fluorescent lamps up with my current setup. Again if I had the funds to do it the best way now I would. I was more concerned with getting a usable building and floor to begin with and everything else was and afterthought.

 

[sparky 1971]

Everyone understands the cost factor. We all understand that you own the fixtures in question. Those lights are still junk and nothing is going to make them a good choice for a shop. That's why I suggested using them in the attic. You are going to have to run wire to boxes and put a receptacle in for each light to plug into. Maybe you can set it up so that two fixtures can plug into one outlet. The receptacles, boxes, covers, wire, and the fact that they are supposed to be gfci protected are going to cost something. Depending on how many switches you decide to use, the wire could approach $200.00. In the future, you have switched receptacles on the ceiling. One of those lights quits and you are going to run down to Handy Dan's Hardware or wherever and buy a plug in led shop light to replace it. The only thing that fixture is going to have over the florescent is the fact that it's a led, but it's still a pos and won't match the other fixtures. If you were to go the strip light route that I suggested, the initial cost would be around $800.00, which isn't very much for a project like this. Yes, I know all about being short on funds, that's why I suggested not going crazy with circuits you don't/won't need. You would have to drop one cable for each row, put the lights up coupled together and pull the rest of the wire (THHN/THWN) through the fixtures. In the future, when a tube goes out, you just take it out, throw it away and put a new tube in. There will be no issue trying to match what you have and you won't have all those ugly *** cords hanging from the ceiling.

In your initial post, you asked for thoughts on what you were going to do. I'm sorry that nobody thought it was a good idea, but it isn't. It's your shop and you can do whatever you want to with it. I won't be using it and I doubt very many others here will either

Ok so someone please tell me if my math is wrong. If I go with the fixture and bulbs listed to get to just the recommended 15 light assemblies it will cost me 675 plus shipping. All the fluorescent lights are already paid for and cost less than $75.00 with a case of new bulbs. I don’t think it will cost me that much to hook the fluorescent lamps up with my current setup. Again if I had the funds to do it the best way now I would. I was more concerned with getting a usable building and floor to begin with and everything else was and afterthought.

 

[Knight511]

Running 2 circuits in one 2-gang makes sense, but not for the reason listed. The setup allows you to run 2 higher amp things at the same time, not swap for a trip. If it trips one, it'll trip the other.

I have 4 circuits (yup, overkill) on one wall right now. One set of boxes at 48" and one at 24". Each height has 2 20a circuits fed by out-of-phase breakers. I wired the 48" height this way because I have tripped 20amp breaks using my shop vac for dust collection while using my table saw or dual bevel miter saw when the saw slows down for thicker cuts. Now I have no worries about the breakers tripping mid cut since the vac and the saw are separated. The lower (24") boxes are wired this way because I hope to convert my table saw from the 120v 1.75hp to the 240v 3hp motor in the future. The outlets are already wired with 10awg wire, so all I need to do is replace the breakers and outlets to convert to the 240v set up.

As for lights, I did not choose the path of converting T9 fixtures like the light thread suggests. I chose a different LED set up based on cost/budget. If the chose is wrong, I will fix it later when the shop is finished and generating some income on its own. That said, I would never install fluorescent lights in my workspaces because I don't heat the spaces (Texas... really don't need to most of the time) and the fluorescents are terrible in the cold.

 

[scribble79]

I just want to bring everyone up to speed on my progress. I did install 6 of the fluorescent throw away lamps and found that I could not get more than 2 cords to reach a centralized location. I decided to remove them all and save for possibly the attic space or just sell off. I did purchase 9 of the metelux fluorescent lamp fixtures and remove the ballast assembly and hard wire. I installed 6 of these lamp fixtures last evening with Sylvania 2200 Lumen 5k led tubes on 2 3-way switches. I was so impressed with the light output of just having the 6 in there so far and i know I will be more impressed when I start getting lights down the center of the garage and not just on 2 of the outer walls. (hopefully the 3 additional lights get installed this evening if time & kids allow) Still thinking of going all out with 15 but may change my mind once all the tools are back and see how they are illuminated.
I appreciate every ones assistance, prodding, and persistence with getting me down the correct path.

Thank You

 

[Bert_]

I like fluorescent lights and I'll still say the shop lights posted are junk. I'll admit I have a couple fixtures in my garage that have an extension cord running to them.