Shop Wiring Help/Suggestion

[cfaas416]

I'm looking at rewiring my entire garage as I will slowly be upgrading it and my first to do is the electrical. Its a basic 3 car 31' x 22' currently only has 2 circuits running to it with 1 circuit dedicated to 2 plugs and the lighting and the other circuit dedicated to the garage doors and 2 other plugs. First off, 4 sets of plugs is obviously not going to cut it so my plans were to make the lights and garage doors on 1 circuit, and taking the other current circuit and converting it for the outside lights only. And now to my first question, is it better to have a dedicated breaker box in the shop to run all of the circuits off of and just have it run back to the main box? 2. I know typically for a house circuits are broken down by rooms to break down the amp loads per breaker but for a shop I was thinking 1 circuit per wall of plugs (approximately 4 plugs per circuit) and then 2 more additional "bigger" circuits dedicated to a specific plug for 1.Future Welding Machine and 2. Air Compressor. Any suggestions would be appreciated as I am a little new to sizing electrical loads and components.

 

['04 Cummins]

How far from the garage to the main panel? If it's far, a pain to run circuits, or almost full already, definitely think about a subpanel in the garage.

I would think 3 or 4 circuits for receptacles should be sufficient, unless you want dedicated outlets for particular equipment besides the welder and compressor you mention. Not sure what type of welder or compressor you are planning on, but usually a 2-pole 50a circuit for a welder, and a 2-pole 30a for most 2-stage compressors.

 

[cfaas416]

How far from the garage to the main panel? If it's far, a pain to run circuits, or almost full already, definitely think about a subpanel in the garage.

I would think 3 or 4 circuits for receptacles should be sufficient, unless you want dedicated outlets for particular equipment besides the welder and compressor you mention. Not sure what type of welder or compressor you are planning on, but usually a 2-pole 50a circuit for a welder, and a 2-pole 30a for most 2-stage compressors.

Its only about 50' to the main breaker but not the easiest underground stretch(Concrete Patio). Its detached but I could pull wires through the attic and breezeway but I'm not sure If I want to pull 6 or 7 pairs that route?

 

['04 Cummins]

Its only about 50' to the main breaker but not the easiest underground stretch(Concrete Patio). Its detached but I could pull wires through the attic and breezeway but I'm not sure If I want to pull 6 or 7 pairs that route?

If that's the case, absolutely a 100a subpanel should be in your plans. Do it once and you'll be all set for future needs.

 

[buzz4041]

I would leave your existing circuits as they are and just start by adding the new additions. First question it depends on how far you have to go to get to your existing house panel with the individual circuits. Will the cost of additional wire justify the cost of a new sub panel and will all these new circuits be able to be housed in the house panel. If not then you you need to add a sub panel. I would suggest you stagger your circuits instead of each wall by one circuit split them up a bit so you don't overload one area at a time. Your "bigger circuits need to be sized to your machines. It all depends on what you have. My compressor requires a 220volt 30amp and the welder 220v at 60Amp. Yours may be 110 volt at 20amp and 110 volt 20 amp. Sort this out along with estimated wire lengths and then people will chime in and get you on your way correctly. Do a quick sketch up of what you want and you can get some real ideas. Don't forget to locate the equipment and work bench on your sketch to help others help you out. Good luck

 

[pattenp]

You say the garage is detached but give the impression that it's attached by the breezeway.

 

[cfaas416]

I would leave your existing circuits as they are and just start by adding the new additions. First question it depends on how far you have to go to get to your existing house panel with the individual circuits. Will the cost of additional wire justify the cost of a new sub panel and will all these new circuits be able to be housed in the house panel. If not then you you need to add a sub panel. I would suggest you stagger your circuits instead of each wall by one circuit split them up a bit so you don't overload one area at a time. Your "bigger circuits need to be sized to your machines. It all depends on what you have. My compressor requires a 220volt 30amp and the welder 220v at 60Amp. Yours may be 110 volt at 20amp and 110 volt 20 amp. Sort this out along with estimated wire lengths and then people will chime in and get you on your way correctly. Do a quick sketch up of what you want and you can get some real ideas. Don't forget to locate the equipment and work bench on your sketch to help others help you out. Good luck

I'm working on the sketches and general shop layout. Will get that posted up here as soon as its done. Thanks.

You say the garage is detached but give the impression that it's attached by the breezeway.

You are correct, its detached from the main house but has a covered walkway (breezeway as it its not a separate structure of its own) to the house.

 

[pattenp]

There may be a technicality of the garage being considered as a separate structure and the NEC only allows for multiple power feeds to outbuildings under certain conditions. Running more than the two circuits may not be an option and you may have to run a sub-panel to be code compliant.

 

[yost69]

And now to my first question, is it better to have a dedicated breaker box in the shop to run all of the circuits off of and just have it run back to the main box?

As was stated 100 amp sub panel is the way to go here.

2. I know typically for a house circuits are broken down by rooms to break down the amp loads per breaker but for a shop I was thinking 1 circuit per wall of plugs (approximately 4 plugs per circuit)

I don't see why that won't work. But if you are using a section of the garage for a work area I would put more than one receptacle in that area. The way I did it was put a 4 gang box in. One hole is for the over bench lights and then put 3 recepts in the other holes.

and then 2 more additional "bigger" circuits dedicated to a specific plug for 1.Future Welding Machine and 2. Air Compressor. Any suggestions would be appreciated as I am a little new to sizing electrical loads and components.

With a sub panel you would have no problems running what ever circuits you needed.

 

[kbs2244]

This site should answer 90% of the detached garage electrical hook up questions.

http://www.selfhelpandmore.com/home...o-dwellings/wiring-a-detached-garage-2002.php

 

[Falcon67]

I usually call the limit at 10 plugs per run, depending. I can fill up plugs in spots, but typically it's not machines - it's little **** like iPhone dock, clocks, TV, radios, task lights, golf cart charger, battery maintainers, etc. Not so much stuff that pulls big current. I have 4 plug runs on 20A breakers in 960 sq/ft. No problems and there are plenty of handy plugs.