Trying to understand my electrical

[Dustin Lane]

Right now I'm working out of a detached two car garage. On the breaker box it has a slot that's labeled washer + dryer/garage and its 30 amp 110/220v breaker. Flipping this cuts all power to the garage, as expected. When I look at the wires in the basement I've got a 12/2 and 14/2 (labeled as such on the wire casing) headed in the direction of the garage, but when I open up the first switch out there it has two sets of red, white, black, and bare copper wire out there. I thought the nomenclature of xx/2 meant two insulated with one bare, but I could easily be wrong. Is this set up even likely? Why would there be two different gauge wires for the same amperage breaker? The reason I am even delving into all of this is because I want to get a 220v outlet out there and was looking at possibilities. Would this be very easy/at all possible on the current wiring? I hope I explained well enough for others to understand, but I can get more info/pictures/anything else if need be. Thanks!

Edit, if it helps, I could also mention that the house and garage were built ~1952 and as far as I know has had no updating done with the electrical.

[John Coloccia]

I don't know what they did in 1952, but unless I'm totally wrong, you need #10 for 30A, and many folks run #8 if it's going to a dryer or something like that.

Tough to tell without seeing how everything is hooked up, but the reds are probably for a 3 way light switch. Why on earth you have 2 red wires is beyond me, unless someone was just running low on wire and just stapled whatever they had inside the wall. Did they even have romex in 1952? It would make more sense if maybe you had 3 or more light switches out there. Then you'd need 4 conductors if the switch you happen to be looking at is one of the 4 ways in the middle. If so, each conductor would be on a different lug of the switch.

Another possibility is the reds are the switched circuit, each one going off to a different light fixture. That would be a possibility if they're on the same lug.

If you really think that 30A breaker is protecting 14 gauge wire, you may want to get to have an electrician give a quick look at what's up. Sounds fishy. There are exceptions, but I didn't think that a dryer is one of them.

disclaimer - I'm not an electrician, and I didn't stay at a Holiday Inn Express last night

[Dustin Lane]

I did a little more investigating and this is what I found. Outside where I first said there were 2 each of red, black, white and ground was wrong. There are two sets of black, white, and grounds one 14/2 and one 12/2. Then there is a single 12/3 that leaves the box with it's red connected to the switch and the black and white connected to what I believe is the 12/2 that comes in. This switch controls a single light bulb, while the rest of the garage branches off of that. Is this SOP wiring?
Back down in the basement the dryer plug has been disconnected halfway down the line. It had 10/3 running to it. At a midway box where I assume it branches to an AC outlet on the main level, a smaller unlabeled sized, comes off, goes upstairs, back down and over to a lightbulb that dies when I turn off this breaker. From this lightbulb's box there are the 12/2 and 14/2 wires that head out to the garage.

On a side note, the AC plug on the main level has never been used so whether it works is unknown and the dryer is a gas dryer that runs on 110v.

[Rod Sheridan]

Hi Dustin, someone has taken the 30 ampere feed for a dryer and creatively re-used it to provide power to other circuits.

It's neither safe, nor legal.

I suggest that you have an electrician look at it, and correct the problem.

Regards, Rod.

[Dustin Lane]

So would it make sense to re-run the line out to the garage with the proper 10/3 and then I'd be able to go with a 220v outlet somewhere?

[Rick Christopherson]

So would it make sense to re-run the line out to the garage with the proper 10/3 and then I'd be able to go with a 220v outlet somewhere?

No, not the way you are thinking, at least. You can't use a 30 amp circuit for general use lighting and outlets.

You can run a 10/3 circuit and install a small subpanel, but at that point, you may want to upsize the conductor size a little to leave room for expansion.

On the other hand, you are permitted to use a multiwire branch circuit to the garage (2-hot, neutral, ground), which will give you both 120 and 240 volt circuits, but you would still be limited to 20 amps.

[Don Jarvie]

I'm still at the planning stages but am ready to run the wire to my garage. I have a detached 2 car and it has no juice.

I could probably get away with 40 amp but an leaning toward 60 since adding up the total amps running at the same time would be TS (15), DC (7) and electric heater (16 - 21) = 38 or 43 plus lights, etc.

Upgrade your system to the subplanel in the garage to give you adequate power and you can then add some plugs now and have room for expansion.

Good luck