Hey guy's Looking for alittle help in wiring a shop up. I just recently finished building my shop and now i need some help wiring it up. I'm going to have (10) 120v 110 plug-in outlet shop lights i got from wal-mart. four in the ceiling for constant light supply. The other six will be on the walls setup to were i can turn them on and off when i need them, like for painting. I will be running a upright 220--7.5hp 80gal compressor. my shop is 16' x 24' if that helps anyone in setting up a wiring diagram maybe for me. Anything will help thanks

Where would you like your plugins placed? how many on a wall, how about your lights, where would you like them placed and how many on each wall. Where would you like your compressor? How big is the power source coming into your garage? Where would you like the circuit breaker panel placed? Where is your door located, roll up doors etc? I can draw it up but need a little direction. I placed my plugins equal numbers on the two long walls, I used two 220V circuit breakers (double 110) and split the plugs so that on each duples one plug was on one circuit breaker and the other plug on the same duplex was on a different breaker, that way if I really wanted too, I could plug two large electrical items into the same duplex and not kick a breaker. The lights I put on two switches and seperated them on two circuit breakers as well. I used 12Ga wire throughout and 20A breakers throughout. I hard wired my compressor directly into a
220V breaker, but dont remember the size. You need to look at the load of your compressor to know what size breaker to use on it. There should be a sticker on the motor, or the control box on the compressor that sais what the current draw is of it. For my main box in my shop, I ran a 220V/100A circuit breaker from my house breaker box, and a set of large wires to my shop to a smaller circuit box. So to turn off the entire shop I have to turn off the breaker in the house. I think I bought the breaker box at home depot or lowes, and it came with 4 free 20A/110V breakers. My main wires coming from the house were 4Ga. I ran 3 wires through 1.5" conduit, over 180ft.

Go to garagejournal.com. I found all my setup tips there.

Not being a smart A or anything but is this a chevelle going in this garage? My question with your shop that size how are you setting it up from the stand point it seems a little tight? My father-in-law built his 25' deep and with a car pulled in and the garage door down you couldn't have a bench in front of the car and it was difficult to get in the front and the back of the car. I guess you could set the compressor in the far back corner and a work bench down the same side wall. But with a 10' garage door centered that leaves 3' on each side, so the car inside with doors open maybe 2' to spare on each side. I built my garage 28' deep by 30' and I think I should have 30' by 60'. With your limited space you'll need to plan carefully. I understand residential restrictions and limited funds but you may want to put your car inside and decide how to lay it out electrically based on space. It'll work, but it will be tight to work in. Any garage is better than no garage. Good luck.:thumbsup:

Where would you like your plugins placed? how many on a wall, how about your lights, where would you like them placed and how many on each wall. Where would you like your compressor? How big is the power source coming into your garage? Where would you like the circuit breaker panel placed? Where is your door located, roll up doors etc? I can draw it up but need a little direction. I placed my plugins equal numbers on the two long walls, I used two 220V circuit breakers (double 110) and split the plugs so that on each duples one plug was on one circuit breaker and the other plug on the same duplex was on a different breaker, that way if I really wanted too, I could plug two large electrical items into the same duplex and not kick a breaker. The lights I put on two switches and seperated them on two circuit breakers as well. I used 12Ga wire throughout and 20A breakers throughout. I hard wired my compressor directly into a
220V breaker, but dont remember the size. You need to look at the load of your compressor to know what size breaker to use on it. There should be a sticker on the motor, or the control box on the compressor that sais what the current draw is of it. For my main box in my shop, I ran a 220V/100A circuit breaker from my house breaker box, and a set of large wires to my shop to a smaller circuit box. So to turn off the entire shop I have to turn off the breaker in the house. I think I bought the breaker box at home depot or lowes, and it came with 4 free 20A/110V breakers. My main wires coming from the house were 4Ga. I ran 3 wires through 1.5" conduit, over 180ft.

You should consult your local electrical codes on the size of the breaker feeding the sub-panel in your garage, there is a thing called diversity (which says all combined loads can't exceed 80% of the main service). In order to use a 100A breaker you would need at least a 200A service.
The size of your service is based on the size of the main breaker that is close to where your demand meter is. Any electrician would need to know this before making a recommendation.

I agree that 12AWG on all your duplex branch circuits is a good idea and I would use conduit and THHN wire (like you would in an industrial installation) not romex. This is beyond code for a residential installation but conduit make changes that you may want to do latter a lot easier!

The Garagejournal.com place is great....

Ron

Hey Rod thanks for taking the time to reply. My shop is 16' with two 6' swinging doors. My shop is 24' deep with a 32" door on one of the 24' walls close to the front swinging doors. I would like two plugin outlet in the ceiling to plug the four lights up there. Those lights will be running long ways of the shop, two toward the front and two toward the back. along the 24' walls i would like three outlets one serving as plugin outlets foor the lights running horizonal on those walls. Up front i will need one for the light running horizonal on the 16' wall up front. i was thinking maybe hanging a light hor. also on the tail 16' wall with the (2) 6' doors once there closed for painting my chevelle, put i need somewhere to plug it in to. The lights on the walls i want them on a separate switch so i can turn them on when i paint. that leaves four switches on the side walls to be constant power there, the two on each side. The two in the ceiling should be hooked up to a separate switch also to be turn on when needed. In the corner on the tail end where my 6' doors on the 16' wall and 24' wall where my 32" side door is where i would like my compressor and breaker box. My outside power source will be coming from a light pole not a house. I can't seem to post pictures from my computer yet so i hope i explained it ok thanks

(which says all combined loads can't exceed 80% of the main service).
Ron


I think I know what you mean, but I think you mistyped. The total of all combined breakers on every load panel, and sub panel have just about always exceeded 100% of the main service. For example, my original main panel has quite a few 20A breakers, 2-double 30A breakers, and a couple of double 20A breakers and I beliebe a double 60A breaker. Even the addition of the 20, and double 20A breakers exceeds the 200A main service. I think what you meant is no single breaker can exceed 80% (if thats the magical number) of the main load, and I can not find it anywhere in my books (not to say it doesnt exist). I also found something similiar, that the total number of loads on a single circuit breaker should not exceed 80% of that breaker. For example, a 20 breaker feeding some duplex recepticals should not be loaded with lots of motors and pumps exceeding 16A total.

Adding up the total of what it says on all the circuit breakers is NOT the load of the panel.
(if that's what ya'll mean)

You should enlist the help of a qualified electrician.
There are many many little NEC rules that need to be followed.

I think what you meant is no single breaker can exceed 80% (if thats the magical number) of the main load, and I can not find it anywhere in my books (not to say it doesnt exist).

I just asked this Q a week ago. I have a 100A main panel, and want to install a 100A breaker to run a sub panel out to the detached garage. No one replied that I could not do it.

I just asked this Q a week ago. I have a 100A main panel, and want to install a 100A breaker to run a sub panel out to the detached garage. No one replied that I could not do it.
Actually it is kind of foolish to use a 100 amp feed to your sub panel from a 100 amp service panel because you will never need or use that much and a 60 amp breaker and feeders would be much cheaper.

Diversity applies from the bottom up. For example on a 20A circuit you are only supposed to load it at 80% as torndown64 indicated.
If you have a 100A breaker it is only supposed to leaded to 80A etc. The total of the breakers in a box is not the total load the box can handle as you have to count the input breaker and/or the size of your service.

Dean said: "You should enlist the help of a qualified electrician.
There are many many little NEC rules that need to be followed."

NEC is National Electric Code which is compiled by the NFPA, National Fire Prevention Association. Go to:

http://www.nfpa.org/catalog/

to order a copy of the 2008 NEC.

Some counties and cities have different variations on these codes, some of it has to do with regional issues, like earthquakes in San Francisco whose code is much different than the NEC.

So Dean is spot on, this can be a complex subject and while you can do it yourself and it will work, if you have a fire, or someone gets electrocuted (usually has to do with grounding issues if someone gets electrocuted; some places required GFI's on all circuits that are not part of living spaces) your insurance company may not cover you if they find new construction that does not meet code.

In the UK I believe they have passed a law that does not allow a non-licensed person to any electrical construction or repair.

As our safety standards increase things get much more complex.

Call a licensed electrician.

Ron

The thing is, IF anything ever happens and the insurance company finds out that electrical work was done by an unqualified person it CAN give them a reason to deny a claim.

Actually it is kind of foolish to use a 100 amp feed to your sub panel from a 100 amp service panel because you will never need or use that much and a 60 amp breaker and feeders would be much cheaper.

Yes, wire is NOT cheap. The run is roughly 50ft. I definitely will reconsider to what you mentioned.

The thing is, IF anything ever happens and the insurance company finds out that electrical work was done by an unqualified person it CAN give them a reason to deny a claim.

Yep, the operable word here is "If". I have observed that sometimes, if the damage is small, you get a quote for the repair and you never see an insurance guy, a check magically arrives in the mail.
In other instances, where the Fire Department determines that an investigation is required, then a bunch of insurance guys show up, claims adjuster, inspector and one time they brought out an independent consultant.

I would say that most people never have any problems with this type of thing, it's just that in the last two years there seems to have been much greater scrutiny than in the past. Not sure why.

The thing is, IF anything ever happens and the insurance company finds out that electrical work was done by an unqualified person it CAN give them a reason to deny a claim.

I have to disagree a bit here, not to argue. If the work was done to code, wether by a licensed contractor or a do it yourself guy, they don't have a case to deny you on. If it was done correctly that is even without a license. Some of the backlash might come from the city or county wanting some money for a fine or for back payment on a permit. This is similiar to how the car companies years ago used to try and say any work done to your car while under warranty by anyone other than a dealership will void your warranty. They now have the onice to PROOVE that the work the other people did damaged the vehicle.

I have to disagree a bit here, not to argue. If the work was done to code, wether by a licensed contractor or a do it yourself guy, they don't have a case to deny you on. If it was done correctly that is even without a license. Some of the backlash might come from the city or county wanting some money for a fine or for back payment on a permit. This is similiar to how the car companies years ago used to try and say any work done to your car while under warranty by anyone other than a dealership will void your warranty. They now have the onice to PROOVE that the work the other people did damaged the vehicle.

I agree Rod BUT hardly any DIY electrical work IS ever done according to code plus if, let's say there was no inspection by the authority having jurisdiction (local building inspector) there would be no way to prove the work was actually done according to code.

just some things to think about

I agree Rod BUT hardly any DIY electrical work IS ever done according to code plus if, let's say there was no inspection by the authority having jurisdiction (local building inspector) there would be no way to prove the work was actually done according to code.

just some things to think about

Even when it is inspected (and passed) by the city or county it is often not to code..:yes:

Code all depends on where you are and who's inspecting. I've seen some pretty horrendous S*it.....

Another plan of attack could be to get with an electrician and discuss having him hang the main panel and maybe one lighting circuit. You pull a permit for the panel and have it inspected. After its signed off, you add the olug circuits and the feed for the compressor. Then run the additional lighting. Your lighting sounds like its all plug in lighting so that makes it even easier.
While the electricial is there hanging the panel you pick his brain on the different codes to look out for when you go to run "your end". This way the most important part ... the main panel and the grounding will be code and legit. The branch circuits are a lot easier to learn how to put in "to code" Booklets they seel at Home Depot will give you a pretty good idea.
We did electricial work like this all the time. The Electricians don't usually mind because their only responsible for what they install. Usually you can find one to do it as a side job. You will be pulling the permit. The inspector doesn't give a **** because you are getting the work inspected and permitted. They could care less if you add some circuits at a later date.
We used to have the utility company install a whole new feed from the utility pole to a garage that we were renting, and they would hang a meter and everything even though we would only have maybe one light and one receptacle hooked up on the entire service.
All anyone is concerned with is what they are putting their name. The electrician is concerned with the panel that he installed and the inspector is concerned with the work that is described on the permit. I just upgraded my service from 100 amps to 200 the city came out and the utility company had to come to run larger lines from the pole and they checked everything out and signed it off without even asking who did the work. If it's done right it doesn't matter. You need to make sure that the main feed is sized properly. The length of the run will determine the wire size. Have the electricial figure that out for you. Good luck.

If it's done right it doesn't matter.

Very well put!

Even when it is inspected (and passed) by the city or county it is often not to code..:yes:
Maybe so but I bet it's not "often"
Anyway, it doesn't matter, you can say "it was done right and inspected" was my point.

Very well put!
maybe, maybe not :D

Someone suggested that the original poster get a copy of the NEC code book. Since its about 2" thick, complicated, and covers lots more than residential wiring, this is probably a waste of time. I used to be a licensed electrician and it was not fun reading...

I didn't see any mention of the contruction of the building. The use of conduit, etc. depends on whether the wiring will be covered or exposed, etc. as well as local codes.

There's no need to use THHN wire since its rated for exposure to things like gasolene, etc. Oridinary solid wire for use in conduit will be fine.

I'd put 20A outlets every 12 feet at about 4 feet up on the walls, drop the lighting, where desired, and put the welder, air compressor, etc. outlets where desired. Code for outlets in a garage oesn't say 12 feet, but its handy to have them...

Finally, I don't suggest that someone with no electrical wiring experience/education do the work. Sorry but I've seen too much bad electrical work.

Someone suggested that the original poster get a copy of the NEC code book. Since its about 2" thick, complicated, and covers lots more than residential wiring, this is probably a waste of time. I used to be a licensed electrician and it was not fun reading...

I didn't see any mention of the contruction of the building. The use of conduit, etc. depends on whether the wiring will be covered or exposed, etc. as well as local codes.

There's no need to use THHN wire since its rated for exposure to things like gasolene, etc. Oridinary solid wire for use in conduit will be fine.

I'd put 20A outlets every 12 feet at about 4 feet up on the walls, drop the lighting, where desired, and put the welder, air compressor, etc. outlets where desired. Code for outlets in a garage oesn't say 12 feet, but its handy to have them...

Finally, I don't suggest that someone with no electrical wiring experience/education do the work. Sorry but I've seen too much bad electrical work.
By the time you get through the book, you'll be too old to need any wiring. :D

What's allowed and what's not allowed WILL vary from location to location, depending on what part of which code they adopt.
That's why you need to check with your local building codes administrator.

As an example, in some parts of the country, EVERYTHING has to be in conduit, around here, only conduit is needed to protect wiring that might be susceptible to damage.