Trade In-Wall Heater for 220v power?

[Alex Burkhardt]

Hey All,

I've currently got an old 3000 watt in-wall electric heater in my 2-car garage workshop. I believe it to be original to the house, which was build early 70's, namely because the dedicated 220v circuit in the panel shares the same moon-man chicken scratch as the rest of the original wiring. I may be wrong, but i digress.

Needless to say, the power situation in the garage is abysmal, and i'm contemplating pulling the heater unit in lieu of adding a 220 outlet. It's a simple 3-wire (2 hot + copper grnd) cable entering the garage directly to the right of my tablesaw. The motor on my Delta saw can be converted over to 220, thus freeing up the *only* other duplex outlet on the wall.

I've only been through one winter in the house, and admittedly as we had just moved in i was not set up to work on projects all that much in the garage. It is a bi-level house, though, and the garage is directly below living space, with conditioned spaces on two sides, and an insulated garage door. I recall firing up the heater once, but the age, and smell of burning off years and years of dust make me hesitant to use it extensively. Central PA can be brutal in the winter, but i'm not convinced the vintage electric heater buried in the wall is the best solution.

Any opinions on making the switch? Am i wrongly assuming that removing the heater box from the wall, adding a new box, and wiring up the appropriate outlet is all that is required? Seems as though i have a dedicated circuit, a good location, and plenty of access to do so.

Lastly, does anyone have any thoughts on potentially feeding a 4th (neutral) wire from the panel, and creating a multi-wire branch circuit where I could pull off one leg for an additional 120 outlet? I know of this only from one or two blogs, and would most likely speak with an electrician before going that route. Just curious if anyone has done it.

Thanks all!

Happy woodworking!

alex

[Mike Heidrick]

What gauge wire is it for the heater?

If you are thinking of wiring a new neutral do it right and run a new wire and put in a proper sized cb for the circuit you plan to use.

Does you elec box even have the neutrals and grounds separated?

[Alex Burkhardt]

What gauge wire is it for the heater?

If you are thinking of wiring a new neutral do it right and run a new wire and put in a proper sized cb for the circuit you plan to use.

Does you elec box even have the neutrals and grounds separated?

Wiring looks to be 12/2 at first glance.

Good question about the separate neutral/ground. I will have to open the panel and check. Are you saying that if they're bonded together it's a non-starter for a multi wire branch?

thanks, ab

[Dan Friedrichs]

Not sure what Mike is getting at about the neutral and grounds. In your main panel (which I presume is the only panel in your house), the neutrals and grounds should be tied together.

12/2 gets you a 20A circuit. That's not a lot of power, even at 240v. What size breaker is it connected to? That might give you a better idea of the wire gauge.

But you're correct that replacing the heater with a receptacle is all you'd need to do.

Personally, I'd investigate the difficulty of pulling a run of 8/3 from the main panel into the garage to feed a subpanel. Then you'd never have to worry about anything, ever again...

[Mike Cutler]

Alex
To provide your table saw with 240 is as easy as you detailed.
Trying to get 120 branch circuits is not.
You have a 2/C cable. It only has two conductors. The ground wire does not count.
Too have branch 120 circuits you have to at least have 3/C cable.
The cable you have,12awg is not very large, and would be limited for total amps on 120 branch circuits.

[Alex Burkhardt]

Not sure what Mike is getting at about the neutral and grounds. In your main panel (which I presume is the only panel in your house), the neutrals and grounds should be tied together.

12/2 gets you a 20A circuit. That's not a lot of power, even at 240v. What size breaker is it connected to? That might give you a better idea of the wire gauge.

But you're correct that replacing the heater with a receptacle is all you'd need to do.

Personally, I'd investigate the difficulty of pulling a run of 8/3 from the main panel into the garage to feed a subpanel. Then you'd never have to worry about anything, ever again...

It's a 20A breaker, which isn't a lot, I agree. On the other hand, the tablesaw is the only 240v capable tool that i own. If it only costs me the box and a receptacle to put in, the price/power ratio is pretty good!

As far as running a sub-panel, it is definitely in the back of my mind. The main panel for the house is located in a bonus room that shares a wall with the garage. Tearing out the wood paneling and refinishing the bonus room is on my to-do list, which would be the perfect time to run a new line.


Alex
To provide your table saw with 240 is as easy as you detailed.
Trying to get 120 branch circuits is not.
You have a 2/C cable. It only has two conductors. The ground wire does not count.
Too have branch 120 circuits you have to at least have 3/C cable.
The cable you have,12awg is not very large, and would be limited for total amps on 120 branch circuits.

thanks, Mike. its sounding like a sub panel would the better approach if i want anything more than the single 240v receptacle.

[Dan Friedrichs]

So with what you have available, you can't do the multi-wire branch circuit, but you can put a 240v plug there.

Can I ask why you want to do that, though? Do the lights dim and the saw bog down under heavy load?

[Alex Burkhardt]

So with what you have available, you can't do the multi-wire branch circuit, but you can put a 240v plug there.

Can I ask why you want to do that, though? Do the lights dim and the saw bog down under heavy load?

Primarily to add an additional circuit of power to the garage. I currently have 2 receptacles in the space located on opposite walls, and one in the ceiling for the garage door opener.

I don't expect the saw to behave much differently based on what I've read, but it will free up one of only two sockets on the wall nearest the saw, which, consequently, is the side of the garage that i have claimed for my hobby.

If I had a larger budget (or any budget, for the matter), I could most likely look to extend the existing 120v outlet to be surface mounted and run conduit, etc., but if and when that happens are anyone's guess.

[Bob Bouis]

You can have both, you know. Just don't use 'em both at the same time.

[Mike Cutler]

Alex

It's hard wiring a shop. Most of us, myself included, are using a garage, or an out building, that wasn't initially wired for the requirements of a wood shop. Same with guys that do a lot of car work and need a welder, air compressor and other tools that require power. My shop is fed from a single 30 amp breaker in the basement, to the sub panel in the garage. I could change it, but just haven't found the need as of yet. I also have some 90' of direct burial to redo when I decide to do it.

Dan Friedrichs has it right;
If at all possible, run a new service from the main panel, and get a sub panel out there. From that starting point everything falls out easier and safer.

[Jim Becker]

The 20amp 240 v circuit from that heating unit will be just fine for powering a tool that can be configured for 240v operation as long as the tool doesn't require more than a 20 amp circuit. Unless and until you start looking at things like 5hp motors, you should be fine. And the 12-2 wire currently in place is correct for a 240v machine circuit. There is no "neutral" required for that type of circuit.

I do agree that getting a sub-panel in the space would essentially solve the power challenges in this shop and if the OP plans on staying in the property beyond just short term, the cost would likely be worth it.

[Joe Bradshaw]

Alex, I have a stand alone shop. I ran all my wiring in surface mounted conduit. I planned all my circuits, but, I have moved outlets and run new circuits since finishing my shop. In your shoes, I would add a sub-panel. I am just finishing up running wiring for a dust collector in my girlfriends shop. She has a shop upstairs and one in the attached garage. I ran surface mounted conduit and put in 3-way switches so that the dust collector could be controlled from either location.
Joe

[Eric D Matson]

If you do run a subpanel, the neutral and grounds will not be bonded together there. Depending on your panel you buy, you may have to remove a bonding strap.

[Brad Alexander]

How far away is your main panel from the garage? How many amp is your main breaker, and, do you have any spare spaces?
In my thinking, you should always set a sub panel in your shop simply for the flexibility and safety of having the breakers in the same room. Depending on the size of the shop, anywhere from 40-60 amp should be plenty. Just make sure you run a 3 wire cable,(or conduit) WITH a ground.
If it's a one man shop, the most you'll be running is a dust collector/vacuum and whatever tool you're using at the same time.
I know it can be a bit costly, but sometimes you just need to get it done right.