I need to run some power and electric heat to the garage. I have one empty double twenty amp breaker I can tap into. I’m thinking of running 12/3 out to the garage from these breakers, and wiring the heater across the both circuits as you normally would, and also tapping into each of them for two ciruits to power a few outlets and lights as if you would just run a 12/3 for two circuits. Is this safe? Legal? or Stupid and dangerous?
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Replies
What you can safely do is put a small sub-panel out in the garage, with one 240 breaker for your heater and one or two 120 breakers in it for lights and outlets. However, that's not very much power...if you're running a heater of any size at all you aren't going to have much capacity for the lights and outlets.
Pull out the double 20 breaker and replace with a double 40 or even a 30. Put a little 4-breaker sub panel in the garage with your double 20 breaker for the heat and one or two singles for your lights and outlets. Depending on the distance, 8/3 or 6/3 to the sub panel. Its not really proper to wire heater, lights and outlets on the same breaker and 20 amps total isn't really enough unless you have a very small heater. There are maybe ways to do that safely, like just running 220 outlets off the one breaker and having lights, heater, etc plug into them, but it isn't a great idea. Another option is to get piggyback breakers which would get you 4 circuits with 2 slots. two outlet circuits for 120 plug-in heaters, another outlet circuit and a light circuit. Then you wouldn't need a sub panel. Either way, materials are not too expensive. The sub panel is the more flexible approach.
"Another option is to get piggyback breakers which would get you 4 circuits with 2 slots. two outlet circuits for 120 plug-in heaters, another outlet circuit and a light circuit. Then you wouldn't need a sub panel. Either way, materials are not too expensive. The sub panel is the more flexible approach."
That raises a couple of other issues.
You can only have "one" circuit to an out building. A 240 or 240/120 circuit is one circuit as there is only on handle (or tied handles) to turn if off.
And to do what you suggest takes a special 4 pole breaker with the 240 on the inter two poles and 120 volts on the out two. Not as easy to find.
I was suggesting (4) 120 circuits and no 240 circuits. The smaller 120V heaters can be used. Then you can use the duplex breakers and tie them all together so they all trip at once. Anything except plain single-pole breakers is about impossible to find in the duplex breakers. If it were me, I'd do the sub panel. Really just as easy as anything else.
You have to remember that the split pole mini breakers are only going to attach to a single bus. He can't get 240V from a single pair, but must use one from each pair to get the two legs for 240V. Since he needs both 240V and 120V his best bet is to use the sub panel as sugested.
Dave
Dave
I don't know how common there are, but there is a special "double tamden" breaker for applications like this.
I just looked in SqD's catalog. it has this note fro two pole tandem 120/240 breakers.
"Order two QOT1515 or QOT2020 circuit breakers and handle tie Cat. No. QOTHT at $2.40 for common siwtching of center two poles".
That gives you one 240 circuit and two independent 120 circuits.
Interesting to see that they also have a split rating tandem QOT1520.
But there are also what are called "quad breakers". There are similar, but come packaged in single unit and can have different ratings.
Here are some;
http://www.allbreakers.com/store.asp/pg!products/grp!367
http://ecatalog.squared.com/catalog/173/html/sections/06/17306009.html
http://www.laner.com/cgi-bin/wwiz.asp?wwizmstr=MVES.SEARCH&pcat=BREAK1
After I posted , I went back down to my shop. Almost the first thing I picked up was some literature about a similar GE breaker. To late to run back up the hill and delete the post, so I just need to get my foot out of my mouth now.
Dave
A very important point to bring up is that in any sub panel the grounded conductor (neutral) and the grounding conductor (ground) must be seperated. Good luck!
Is the garage attached to or detached from the house?
The garage is attached to the house. I'm gonna have to run the wire outside in a conduit and get some "invisible" paint for it to it isn't too conspicous, it has to run across the front of the house.
GeoffH,
I'm gonna pipe in here. You have got to get a real electrician in on this project. If you can't afford the cost to hire the guy, you should'nt do it. Electric fires are not nice. They kill a lot of people every year. You have got to respect electricity. There is no second chance.
Maybe I go a bit overboard, but this has hit to close to home too often.
Karl
Restoring the past for the future.
Curly, I'd be interested in hearing some of your "close to home" stories. Wiring doesn't scare me, and I try as best I can to follow code (though in remodel situations, sometimes that's quite a challenge -- I think everyone has 'buried' a junction box at one time or other -- but the reason I started the thread was to get a bead on the safest way to do what I needed, and I think the sub-panel is the way to go.