My garage's wiring is a mess and I'd like to fix it up if I can. Half the lights, switches, and outlets don't work, it all really needs an upgrade. The only source of power that I have found is a black and white coming from the house on a 30 amp breaker. I want to put new lights around the ceiling, switches, and plugins but have no idea where to start and how to incorporate the only source of power from the house to the whole garage? Any suggestions? I'd like to keep it as simple as I can. I had my Dad look at it and he wanted to add a new meter, with 10 breakers and go the whole 9 yards. Is there a less complicated, functional way of doing this? Please and thank you so much!

You could just add another breaker to your already existing box. I had 2 extra breakers added to my breaker box when I had my shed wired up so I could use heavy duty stuff out there such as a circular saw AND a coffeemaker at the same time. I had 2 30 AMP breakers added. Just what do you plan on doing out in your garage such as what power tools do you plan on running at the same time? You could hire a local electrician and have him map this out for you so it's done to code as it WILL need to pass the county's code otherwise it will have to be reinspected after you pay your fine for not pulling a permit for this work. The county gets a little hinky when it comes to do it yourself electrical work and wants to keep you safe from yourself. Mine was done professionally and only cost me around $200. I have lights in the ceiling and a light switch also.

I assume that 30 amp breaker is on your house panel so you only have one set of wires or cable going to the garage. "he wanted to add a new meter, with 10 breakers " I'd keep dad away from this so nobody gets hurt. Make us a list of what you want to have in the garage and what type of projects or work you plan like table saws or welders. Unless you plan on trenching a new cable out to the garage you aren't going to get a sub panel, which is actually the way we do most garages.

The simple method is to use the existing feeder. This one circuit may very well be sufficient for your needs.

Change the breaker to 1 pole 20 amp.

Install a junction box on the existing feeder in the garage and continue on with new #12 cable to the new lights and outlets.

One 20 Amp 120 volt circuit can serve the lights and some outlets, with the understanding that only one tool or appliance can be used while using the lights.

The amount of power left for tools will depending on the wattage of the lighting you install.

How simple this will be will depend on how many lights and outlets you need.

You can do your own electrical work in a single family home that you reside in. Check with your local electrical inspector for their rules.

Any 120 volt general purpose receptacles in a garage will need to be GFI protected.

First verify that the cable to the garage is 10-2 cable.

Purchase a small 6 space sub panel, an extra ground buss, a 30 amp breaker and a couple of 15 or 20 amp breakers.

Install the extra ground bus in the sub panel. Mount the sub panel. Connect the cable form the main panel to the 30 amp breaker and the neutral buss. Connect the ground wire to the extra ground buss you installed.

Run a lighting and outlet circuits using the other breakers you purchased. Connect neutrals to neutral buss and grounds to ground buss. TK's way gives you 20 amps to the garage, this way gives you 30 amps but cost you about $30 more.

Also keeps you out of the main panel.

HK, since there is only and black and white as reported by the poster, and we will assume a ground wire, this can provide either 120 or 240 volts, not both.

Panels are built for both voltages, all rated 120/240 volts.

How would someone use a 120/240 volt panelboard with only 120 volts feeding it?

Use only half of the sub panel spaces. I suppose you could use a double breaker and splice to each.

Favoriteclash,

TK caught me in an error. Purchase a 30 amp double breaker and connect the black of the cable from main panel to each side of breaker. That will energize all the remaining spaces with 120 volts. A single breaker will only energies every other one of the remaining spaces.

The only 2 wires (no ground, its an older house) coming from a breaker box on the back of my house is a black and white 10 gauge. Its currently on a 20 amp breaker but I was told you could run a 30 on a 10 gauge, and that's what I was hoping for, I don't want to be 2 limited on power.

I'd like lights throughout the ceiling, outlets throughout the walls so I can run TV, radio, a mini fridge, and maybe a power tool no occasion. I read that on a 120 volt 30 amp I have a max safe wattage of about 2900. I calculated all the power usage I'll have out there, with a few extra to spare for the occasional power tools, and I'm good with the 2900.

I'm just lost as to how to start the wiring, starting with those black and white, 10 gauge wires coming into my garage.

Any more questions or suggestions please feel free, and thanks again!

Just curious here. It seems to me some serious questions have be ignored.

First: Is the garage part of the residential structure or is it a stand-alone building?

Second: If the cable to the garage is not a four wire cable, then it should be replaced with the correct size and type cable.

Third: If the garage is a stand-alone building, then a grounding system must be considered.

Also, you are not correct in some of your assumptions. For example, you cannot use a 120V 15 or 20 Amp receptacle on a 30 amp line. A 30 amp receptacle is not the same as the 15 and 20 amp. Nor are the plugs that go into them.

One other general guideline you need to be aware of is the loading of the circuits.

For example, a multi outlet circuit (a circuit with more then one outlet) can only be loaded to 80%.

If there is only one outlet, then the full amperage can be used.

On a multi outlet 15 amp circuit, the max load should be approximately 12 amps.

On a multi outlet 20 amp circuit, the max load should not exceed 16 amps.

If you are doing all new wiring, then you must use cable that contains a ground, for example, 14/2, 12/2 or 12/3.

Also, just curious, where are you located because you would be wise to talk with the local State or County Electrical Inspectors to determine the correct edition of the NEC that is required in your area. Besides, you are going to need a permit and inspections before you will be able to go any further after the work is completed.

Thanks again HK, I've taken into consideration your thoughts and am planning the layout this week. I'm replacing all the old wiring, installing some lights, and power through out, thinking about making it a game room as well as a place to hold all my toys. Its going to be great when I'm done.

What is the distance between the house and Garage?
If you decide to run new electric, while trench is open, don't forget about water, TV, Phone, Computer, Alarm wiring?

I like tkrussels response the best...

Use the existing feeder, okay I can do that. I have verified it's a 10/2 on a 30 amp breaker. There is no ground and I'm wondering if there's a simple way to install one. I have a grounding rod.

Why do I want to change from a 30 amp to a 20? Isn't that going to limit my power? I thought you could use 120v 30 amp on a 10 gauge wire?

Junction box, Okay, sounds good. Will I also be able to put in switches to control these lights and stuff?

The only thing that will run constantly will be the freezer and maybe someday a minifridge. I'll have a TV, radio, some game tables out there for fun. I hardly will ever use power tools, I don't have any and I'm not that mechanically inclined.

It's a 25x25 2door garage, nothing fancy I want some basic flourecents for light around the ceiling. And a couple outlets per wall for easy access to plug things in. Again, not a mechanic, most things going out there will be for a fun room atmosphere, so no power tool use.

Got it, okay, I've got my shopping list started and I plan on getting the bulk of it this weekend. If you have any more suggestions, feel free and thanks again.

"I like tkrussels response the best... Always a good choice!

Use the existing feeder, okay I can do that. I have verified its a 10/2 on a 30 amp breaker. Okay, Hold on for a minute, please. Is the garage part of the residential structure or not. This is critical information.

There is no ground and I'm wondering if there's a simple way to install one. I have a grounding rod. "This question cannot be properly answered until we know about the structure of the garage! If this garage is part of the residential structure, then a ground from the main panelboard must be run to the garage. It would be simpler to pull a new cable that has a ground inside the sheath. However, if this grage is a stand-alone, then you would be wiser to run a 10/3 cable feeder to the garage and use a 240 feed from the main panelboard to feed the garage. Then install a second panelboard in the garage. The garage will need at least two grounding rods aproximatley 6 ft. apart. This is for the protection of the building itself. In the second panelboard. Ground and Neutral have to be isolated. You cannot use one bus bar for boith circuits. The ground wire from the main panelboard would connect to the ground busbar, which will also be connected to the grounding rods.

Why do I want to change from a 30 amp to a 20? Isn't that going to limit my power? I thought you could use 120v 30 amp on a 10 guage wire?

Again, infomation is needed from you. If and only if you are using a single circuit only, you can use the existing feeder. Yes a 10/2 cable will support 30 amps, however, you cannot place 15 and 20 amp receptacles on a 30 amp feeder. They must be protected by a 15 or 20 amp breaker, respectivley.

Junction box, Okay, sounds good. Will I also be able to put in switches to control these lights and stuff? Yes you can place switches to control lights and receptacles, however, when the stuff goes into the room you may find the circuit overloaded and without any way to fix the circuits because you are under powered.

The only thing that will run constantly will be the freezer and maybe someday a minifridge (Okay, the freezer and refrigerator are not considered to be continous loads. This is because they cycle on and off.). I'll have a tv, radio, some game tables out there for fun. I hardly will ever use power tools, I don't have any and I'm not that mechanically inclined.

Its a 25x25 2door garage Just by the size alone the garage is going to require 1,875 "Volt/Amps." If this is a stand-alone garage, you are also required to install a light over the entry way. The garage door is not an entry way. A 30 amp feeder at 240 volts will yield you 30 X 240 = 7200 VA - (20 Amps X 120 Volts = 2400 VA).

Given that this has to be a multi outlet circuit, the available VA would be 2400 X .8 = 1920 VA. This calculation says that you need a minimum of 1875 VA for lights and some general use receptacles. You will be razor blade thin on 20 amps., nothing fancy I want some basic flourecents for light around the ceiling. And a couple outlets per wall for easy access to plug things in. Again, not a mechanic, most things going out there will be for a fun room atmosphere, so no power tool use.
"

You may have liked my response the best, however Don zooms in on several important issues.

Can you tell that things have been slow here, and Don has a great deal of pented up advice? Nice job Don.

Now that we know the cable has no ground is the biggest issue. There is no short cut around not having an equipment grounding conductor.

You need a new feeder cable with a ground, period.

Just because you have a 30 amp circuit is ho help when you need 15 or 20 amp receptacles.

The breaker needs to be a 20 amp to protect the receptacles, period.

If you decide to install 15 or 20 amp receptacles and continue to use a 30 amp breaker, then be sure your insurance is paid up, oh never mind, the fire inspector will find this serious code issue and deny any claim.

You may as well get prepared to install a new feeder cable, one of which can handle more that one 20 amp circuit.

Get back with what you decide to do and we can help from there.

I've installed a junction box to the existing wiring coming into the garage like tkrussell mentioned. Now from there is what I'm confused about.

I'd like 2 receptacles per wall in the whole garage so a total of 10.

I'd like my ceiling lights to function between two 3way switches. That way I can turn on or off the lights at either end of the garage.

I'd also like to install a dawn to dusk motion light at both ends of the garage.

Is there an easy way to tackle this project? Any suggestions welcome, and thank you!

Scratch my last response. I've seemed to have gotten ahead of myself. I want to focus on what donf is saying.

Hello donf, my name is Ken. Seems you know a thing or two about electricity. I'm learning and it doesn't help when I have a father that's still looking for some lost bolts if you know what I mean.

The garage is a stand alone structure. 15 ft from my house to be exact.

I had a single pole 20 amp breaker 10/2 cable going to the garage, but was told a 30 amp would give me more power.

All I'm looking to do is replace the pos wiring, receptacles, and lights that are in the garage now, with some 3 ways for the lights, and yes I need some lights put on the outside because there is none.

The volt/amp calculations you came up with are interesting, can you help me get my garage up to par and sufficient enough for what I want?

So your saying the 10 pack of 125volt/15 amp receptacles were a waste of money because their the wrong ones?

Wow, my garage is off limits to my dad for a while till I can sort this out. Any suggestions welcome, and thank you again!

Ken,

Both TK and Strat are much more experienced than I am.

Since your garage is a stand-alone building, then there are specific requirements you must follow.

1) The feeder from your main panelboard to the garage must be a four wire feeder.

Bring just 30 amps over to the garage is a mite thin. I would suggest a larger load or plan ahead by putting the cable inside a conduit so that if you need to replace it, you do not have to dig the cable up just to replace it.

Receptacles in the garage must be GFCI type receptacles or protected buy a GFCI breaker.

The volt amps I used came from the NEC formula for general connections.

I need more information if you want more assistance. Yo can send me a PM and I will do what I can to assist.