Light and electrical question

[Coach James]

Hey everyone,

Finally getting a shop build at my place. 30 x 40 feet. Two manual roll up doors, 1 man door, and a bathroom.

I have two questions.

One is lighting. It will be LED, 4 foot tubes. The bid includes 4 fixtures of 2 bulbs each. Based on your experience, will that be enough light for my 56 year old eyes.

Second is electrical service. Original bid included 30amp service. I questioned that as too small and they said they could go up to 50 amp if they can run that much from my house service. My house has two panels, each with a 200amp main breaker.

Do you think 50 amp to the shop would be enough? At various times, I will be running a table saw, 240V welder, possibly a 30-40 gallon compressor, but that is becoming less likely as cordless tools get better.

No intention to ever install a 2 or 4 post lift. Maybe a window AC or single mini split some day.

I don't want to put in a service that is adequate now, but has almost no capacity for me to add later.

Any other things you realized you wish you had included after your shop was built?

Thanks
Coach

 

[thewatusi]

Do you think 50 amp to the shop would be enough? At various times, I will be running a table saw, 240V welder, possibly a 30-40 gallon compressor, but that is becoming less likely as cordless tools get better.

No intention to ever install a 2 or 4 post lift. Maybe a window AC or single mini split some day.

Yes 50 amp is plenty.

 

[Muggzy]

I have an old Lincoln tombstone welder in my garage and that alone requires 240v, 50a. My compressor is a 3 hp 240v and requires a 30a breaker. The heater is 240v, 20amp that's barely adequate and I've only got a small 2-car garage. Then I've got the benches wired with 120v, 20 amps. Not that I've ever had all of it running at once, but I think if I was welding out in the garage with the lights and heater on, you'd be pushing the limit with 50a.

You don't say how big of welder you're thinking of, or how big your table saw is. A window AC unit is prob 15-20a tops.

I'd wanna be up around 75-100a

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[lakelandcat]

Coach I just put in 2/ 4 bulb LED T-8 Daylight bulbs. My shop is a 18x20, that was good for the back half and would prob. be good for the front, but one thing to take into consideration is the light source when your garage doors are open. Speaking as a woodworker/mech./get out the house type of guy its nice to have several sources and brightnesses. My rule of thumb is you can never have enough light, but when I just want to chill with friends drinking beers and listening to the tunes I don't want to blind everyone. I have 4 recess fixtures on a separate switch. I will prob. put in 2 more 4' T-8 daylights before all is done. Mike. P.S. As far as your power, famous last words. "I thought it was big enough!"

 

[sparky 1971]

I don't think there are enough lights. I just finished a 40X60 with 16' ceilings. I put (17) 8' and (3) 4' led tube fixtures in it. A total of 74 18watt 5000K clear lamps. According to my sales rep, it should be 55 foot candles. I don't know what the fc is, but it passes the eye test. Your building is half the size, but I am sure the ceiling is a lot lower too. That is going to keep the light from spreading out. Eight lamps won't cut it.

50 amps will probably be enough, but there is no reason they can't run 100 amps out there... well, 90 amps using #2 aluminum wire for the code nazi's. I would insist on them running at least a #2 wire and give you a 90 amp breaker in the house. The cost difference for material is minimal. I would rather have something and not need it than the other way around.

I ran #2 to my garage and used a 60 amp breaker because that's what I had on my truck. It was fine for over five years. Then the wife's kid comes to town with a camper. Camper was plugged in, AC on and I was using the plasma cutter. When my air compressor kicked in, the breaker tripped. It now has a 100 amp breaker. That's what I happened to have on my truck.

Edit: I just got the go ahead so next week I will be starting a 50X96X16 building. The lighting in it will consist of (40) 8' four lamp tube fixtures. That's 160 5000k lamps. That may be a little more than necessary, but the owner wants to make sure it's plenty bright.

 

[lakelandcat]

I don't think there are enough lights. I just finished a 40X60 with 16' ceilings. I put (17) 8' and (3) 4' led tube fixtures in it. A total of 74 18watt 5000K clear lamps. According to my sales rep, it should be 55 foot candles. I don't know what the fc is, but it passes the eye test. Your building is half the size, but I am sure the ceiling is a lot lower too. That is going to keep the light from spreading out. Eight lamps won't cut it.

50 amps will probably be enough, but there is no reason they can't run 100 amps out there... well, 90 amps using #2 aluminum wire for the code nazi's. I would insist on them running at least a #2 wire and give you a 90 amp breaker in the house. The cost difference for material is minimal. I would rather have something and not need it than the other way around.

I ran #2 to my garage and used a 60 amp breaker because that's what I had on my truck. It was fine for over five years. Then the wife's kid comes to town with a camper. Camper was plugged in, AC on and I was using the plasma cutter. When my air compressor kicked in, the breaker tripped. It now has a 100 amp breaker. That's what I happened to have on my truck.

Thats what I'm talk'in about, see your shop from space. I'm running 200A with 4g copper, straight from the meter so it won't interfere with the house. I did have to pound in 2 ground rods. but I can run anything. When I had to have a cert.elec. hook me up he ask me why? I told him thats what came with the panel box I got on clearance from Lowes, had 20a breakers and 2 100a mains, cost me $10. Why?, because I can.

 

[ryantowry_81]

are you talking about 50 amps total or just for lights?

If you ever plan on using a plasma cutter I would shoot for 100amp or more. I found in my lst house having the 220v compressor and the plasma running sucked enough juice to dim the rest of the house with a 150 amp panel. my wife hated it. I had to start doing most of my plasma cutting at night when her and the kids were asleep.

 

[manwithtools]

I don't think there are enough lights. I just finished a 40X60 with 16' ceilings. I put (17) 8' and (3) 4' led tube fixtures in it. A total of 74 18watt 5000K clear lamps. According to my sales rep, it should be 55 foot candles. I don't know what the fc is, but it passes the eye test. Your building is half the size, but I am sure the ceiling is a lot lower too. That is going to keep the light from spreading out. Eight lamps won't cut it.

50 amps will probably be enough, but there is no reason they can't run 100 amps out there... well, 90 amps using #2 aluminum wire for the code nazi's. I would insist on them running at least a #2 wire and give you a 90 amp breaker in the house. The cost difference for material is minimal. I would rather have something and not need it than the other way around.

I ran #2 to my garage and used a 60 amp breaker because that's what I had on my truck. It was fine for over five years. Then the wife's kid comes to town with a camper. Camper was plugged in, AC on and I was using the plasma cutter. When my air compressor kicked in, the breaker tripped. It now has a 100 amp breaker. That's what I happened to have on my truck.

Great advice here. I think you for sure need more lighting. I had eight two lamp 4' LED's in my 30 x 40 at 10 feet high. I wished I had twice that much light to fully illuminate the corners and help when working under under vehicles.

I'd install them on two circuits, only turn on all the lights when you need it.

The #2 wire is also a sound suggestion, it's a minimal cost increase and you never know when you'll need more power.

 

[Bert_]

That number of lights is comical. It sounds like they think it's just a storage building. 20 of those fixtures would be a good guess. That's assuming a ~10' ceiling.

Running 90-100A is a very small price difference when doing it from the start.

It sounds like you need to be your own expert. Tell them exactly what you want or expect it to be designed for nothing more than storage.

 

[gpiggaz]

I would suggest 60A minimum, (some would say 100A) and it sounds like you might have 400Amp service at your house now- of course someone should do an NEC load calculation to make sure you have enough service to support 60A- If you plan to run a welder and a compressor, you could max out 50A service- As for lighting, I can't remember where right now, but somewhere in the Electrical and Lighting area here there is a link to a calculator for lighting, I think that would be my advise, run that calculator and then use it's outputs for determining the lighting - with LED bulbs, you probably will only need one circuit for lighting too. Good luck and post up pictures of the progress as you get it built over in the garage thread...

 

[dfiler2]

Congrats on the new shop. I would consider going with at least a 90 amp service. My shop is 26 x 38 and I have 36 4' T8 bulbs and I just recently put in an extra 3 4' LED lights directly over the work bench.
Enjoy!

 

[Coach James]

It would be 50 amp to cover everything. That is what is concerning me.

Thanks for the replies. The welder I am looking at is either a Miller or Hobart in the 200-215 amp range. I think Hobart recommended a 40amp breaker for those.

I have been reading and calculating regarding the lights. Using Lumens, several articles recommended at least 70 Lumens/sq-ft. That would be 84,000 Lumens. If I used two bulb fixtures, putting out 3,800 Lumens total, that would be 22 fixtures. I have also spoken with a couple friends that have similar size shops and they both used 10, twin bulb fixtures and say they have plenty of light.

Tomorrow I will count the fixtures and bulbs in my building. the gym area is 11,000 sq-ft, but I don't remember the exact number of fixtures. Plus they are 4 bulb T-8 fluorescents.

Anyone use the LED fixtures with the integrated bulbs?

I think I may start a shop build thread to keep all this stuff in one place.

Coach

 

[Bert_]

It would be 50 amp to cover everything. That is what is concerning me.

Thanks for the replies. The welder I am looking at is either a Miller or Hobart in the 200-215 amp range. I think Hobart recommended a 40amp breaker for those.

I have been reading and calculating regarding the lights. Using Lumens, several articles recommended at least 70 Lumens/sq-ft. That would be 84,000 Lumens. If I used two bulb fixtures, putting out 3,800 Lumens total, that would be 22 fixtures. I have also spoken with a couple friends that have similar size shops and they both used 10, twin bulb fixtures and say they have plenty of light.

Tomorrow I will count the fixtures and bulbs in my building. the gym area is 11,000 sq-ft, but I don't remember the exact number of fixtures. Plus they are 4 bulb T-8 fluorescents.

Anyone use the LED fixtures with the integrated bulbs?

I think I may start a shop build thread to keep all this stuff in one place.

Coach

Lumens/square foot is not a valid means of measurement. It ignores many important factors like ceiling height and reflectance.

A 20 ceiling will need more lights than an 8' ceiling even if the room is the same square feet. A room painted a dark color, or unpainted wood, with need more lights than one painted white.

You need to use foot candles. Dialux is great but probably more than you want to learn. If you want something simple the acuity interior tool can give you a good idea also

 

[cybrdyke]

Using Lumens, several articles recommended at least 70 Lumens/sq-ft.

Any source of information that would reference lumens/sq-ft should be dismissed as nonsense. They obviously have no idea what they're talking about.
If you'd link that source, I'd be happy to let them know.....

 

[Coach James]

Any source of information that would reference lumens/sq-ft should be dismissed as nonsense. They obviously have no idea what they're talking about.
If you'd link that source, I'd be happy to let them know.....

LOL. I have no idea which one it was. I did a Google search for shop lighting and several came up stating the same thing.

Coach

 

[Bert_]

If you post the ceiling height, wall coverings and paint color if any, I or someone could probably run the calculation for your building. You could also look through the lighting layout thread. Chances are you will find something very close to your building.

 

[sberry]

A 211 welder draws 25 wide open. That's the old ones, inverters even less.

 

[aggie113]

30x40x18 here, I was able to get by with 8 wide panel highbay led lights. Many said I would need more but with the height the light is fine at floor level. I would consider more lights for proper spread unless also very high up.

 

[teamextreme]

As a reference, my shop is 100 sq feet smaller, with 9 ft ceilings and my eyes are 1 year younger I have 17, 4-foot 2 lamp LED's (the ones listed in the lighting FAQ from bees lighting) and it is just barely adequate. I couple more lights wouldn't have hurt, but it works.

 

[bczygan]

My 9 1/2 x 19 1/2 has 8 4' 2 tube LEDs or twice what you propose for a space 6 times as big.

I would have at least 24 of those 2 tube fixtures.

Bill

 

[Terry D]

I am wiring a 24 x 30 shop with 10ft ceilings right now. Installing (12) 4 ft fixtures about 4500 lumens each. That will give about 60 foot candles at a 30" plane. There are alot of lighting calculators online to help you. The lighting in your bid is no where close to what you need.

I would defiantly go with 90 or 100 amps out there. Sounds like you have a 320 amp main service to the house. Unless you critically close to being over loaded, which is unlikely. Do you have electric heat in the house?

 

[Innovate1]

I am wiring a 24 x 30 shop with 10ft ceilings right now. Installing (12) 4 ft fixtures about 4500 lumens each. That will give about 60 foot candles at a 30" plane. There are alot of lighting calculators online to help you. The lighting in your bid is no where close to what you need.

I would defiantly go with 90 or 100 amps out there. Sounds like you have a 320 amp main service to the house. Unless you critically close to being over loaded, which is unlikely. Do you have electric heat in the house?

That's good advice. I would do AT LEAST 60A. Should be no problem off your main panels. I did 100A off one of my two 200A panels. Doubt I will ever need it but not that much more to do and I won't likely have to worry about it later.

I put 12 two tube lights in my 30 x 40 x 14high. It is plenty for me although others recommended more. Four 2 tube lights in your space isn't going to be enough to do much. If you plan to use it for anything but storage you need more.

 

[sberry]

There is no reason not to use a number 2 alum wire here.

 

[sberry]

I have never had to come and put a 90 in place of the 60 we normally install but that wire makes a common garage never tell it isnt sitting on top of the service. Will do an electric car or a full size motorhome if it ever came to that. Go gettem the wire if you got to.

 

[MikeF2316]

One thing I'd factor in: Is it possible that you may charge an electric car out there sometime in the future? I believe that the maximum charge rate on a Tesla now is 17.2 kW, or nearly 72 A at 240 Volts. Add in the downrating for continuous load and you're going to need 90 - 100 amps just for that.

 

[vavet]

I had a 24x32x12 built a few years ago. I opted for 100amp service on a subpanel from the house. The cost to redo it later is huge when you consider trenching it again and in my case, it would require patching the asphalt driveway because the wire runs under the driveway installed after the garage was finished. Add a Cat6 cable in there for a little more futureproofing.
I have ten 4ft twin tube fixtures and I consider it to be a good start. I wish I would've had him put a few of them on a separate circuit. This bit me when I took them down for drywall and was trying to put them back up at night.
I added some additional outdoor lights that I'm quite happy with and lots of additional 120v receptacles. I knew I would have a car lift going in so he wired for that and for the mini-split that I have too. I'm glad I talked to the electrician because I'd indicated that the mini-split service was to be located inside. he told me they usually need the service outside...and it did. I didn't know that at the time.

It's easy to feel like you're going overboard with electrical service, but it's difficult and/or expensive if you need to add a little more later.

 

[loganb]

90 or 100 amp service is going to better serve you. Even at 50 amps you would possibly have to be diligent about what equipment might "auto cycle" on and off as if you were cutting something with a corded saw and the air compressor and AC kicked on while the saw was running you likely end up in the dark....

Also agreed with the other posters that is nowhere enough light for anyone who is on this forum. Good enough for a storage or parking garage but any sort of work will have you frustrated and looking for temporary lights. Lots of similar layouts in the lighting sub forum to get ideas from

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