Need to add more heat

[krisway]

I'm looking to finish insulating my garage and adding heat. I currently have two 2000watt heaters running from a dbl pole 30amp breaker. I was hoping to add another 2000w heater for a total of 6000watts, but I'm thinking this is too much for the 30amp breaker. Thoughts?

I have room in my panel to add another double pole breaker, so adding a 20amp dbl breaker would may be a better option?

 

[pattenp]

6000W @ 240V is 25A, so it won't trip the 30A breaker. That's the max I'd put on the circuit.

 

[krisway]

6000W @ 240V is 25A, so it won't trip the 30A breaker. That's the max I'd put on the circuit.

Thanks. I read that a breaker should only be loaded to 80%, and the above would be 83% loaded. Do you think this is still safe?

Also, would 12/2 wire be okay or would you recommend 10/2 wire?

 

[frankush]

A 30A breaker will require #10 gauge wire and you should be ok.

 

[krisway]

A 30A breaker will require #10 gauge wire.

Thanks. Will 12/2 be okay for a 20amp breaker running a 2000watt heater?

 

[pattenp]

#12 is rated for 20A.

Edit: You're right on the 80%. That's a factor for sizing circuits based on anticipated load. You'll be okay at 83%, you have a little leeway.

 

[VHF]

To run three (3) 2000W heaters at 8.3A each, you could put a 40A 240V breaker in your panel, run 8/3 wire to a subpanel with three (3) 15A or 20A 240V breakers, one for each heater. You could run 12/2 from the subpanel to each heater.

 

[krisway]

I think the safest way for me is to run one 2000w heater off a 20amp double pole breaker with 12/2 wire. And run the other two 2000w heaters from a 30amp double pole breaker with 10/2 wire. Sound good?

 

[pattenp]

Why do you need 10/3 and not 10/2 for the other two heaters?

 

[krisway]

Why do you need 10/3 and not 10/2 for the other two heaters?

Typo. Should have read 10/2

 

[vartz04]

Why not just get a 5-6000 watt heater?

 

[RCStocker]

Electric heaters are very expensive to run. You might want to go to a propane heater. One larger heater will put out more heat and be cheaper to run that a few smaller heaters

 

[dave67fd]

Electric heaters are very expensive to run. You might want to go to a propane heater. One larger heater will put out more heat and be cheaper to run that a few smaller heaters

It will depend on your location. Some electric kwh rates are cheaper vs propane per gallon prices. You need to do the math to see which is more effective. It also depends on the area size. If a considerable large area, propane may be more practical. NG is a no brainer.

 

[VHF]

I think the safest way for me is to run one 2000w heater off a 20amp double pole breaker with 12/2 wire. And run the other two 2000w heaters from a 30amp double pole breaker with 10/2 wire. Sound good?

That's fine... safe and code-compliant!

 

[Alchymist]

Electric heaters are very expensive to run. You might want to go to a propane heater. One larger heater will put out more heat and be cheaper to run that a few smaller heaters

??? If you are referring to electric heaters, the size and number doesn't matter 3 -1000 watt heaters will put out the same heat as 1- 3000 watt heater, and the cost to run is the same. Watts is watts. (Might be a very minor difference in fan motor power). And where I live propane vs. electric is close to a wash, it will vary in other locations.

 

[dimarcelli]

Or you could do one 2000 watt heater with 14/2 on a 15 amp double pole breaker. Throw the other two on a 20 amp double pole breaker with 12/2.

2000 watts @ 240v is 8.3 amps, good enough for 14/2 and 4000 watts @ 240v is 16.6 amps, which 12/2 would handle fine. Just a suggestion if you want to save some money. Only downside is, running 10/2 will allow you to swap the two 2000 watt heaters later on down the road for a single 5kw unit. It's all in what you anticipate for the future.

EDIT: Sorry i didn't read that you already had two heaters up and running. If you add the third 2000 watt one, like i said 14/2 with a 15 amp double pole would be my option. More volts = less amps and smaller wire.

 

[swiss]

Hey, krisway, not to stray off topic but how big is your shop? I'm just finishing a 20x23 and ordered 2 4000w heaters, hoping they'll do the trick.

 

[vern1]

I dont know where either of you are but i am in Toronto and just went through some of these deliberations. I have a 4800w heater in my 20x20 space. My garage has little to no insulation which is obviously a big problem but the 4800 is not very effective at warming up the space. I am going to use it occasionally on weekends to work on the car so i just got a 60k btu propane bullet. Fire that up for 30 mins or so and ready to go. Much faster than waiting for the electric. Then i just use the electric to maintain

 

[swiss]

Hey Vern I'm just south of you,in Niagara. I'm going r14 in the walls and r30 in the celling covered with drywall. I have a 10 ft door with r16. Fairly good as far as insulation goes. I did consider a portable to get it up to temps and the electric to maintain it if I need to.

 

[vern1]

Hi Swiss, your place is an insulated fortress compared to mine! However i do find the propane heater (i think it was $120 at Rona) very good at getting it up to temp fast. With all that insulation the electric should do well maintaining it

 

[krisway]

Hey, krisway, not to stray off topic but how big is your shop? I'm just finishing a 20x23 and ordered 2 4000w heaters, hoping they'll do the trick.

My shop is 16x36. General rule of thumb is 10 watts per sq foot in and insulated garage. My shop is just under 600 sq ft, so 6000w should do the trick.

 

[krisway]

Or you could do one 2000 watt heater with 14/2 on a 15 amp double pole breaker. Throw the other two on a 20 amp double pole breaker with 12/2.

2000 watts @ 240v is 8.3 amps, good enough for 14/2 and 4000 watts @ 240v is 16.6 amps, which 12/2 would handle fine. Just a suggestion if you want to save some money. Only downside is, running 10/2 will allow you to swap the two 2000 watt heaters later on down the road for a single 5kw unit. It's all in what you anticipate for the future.

EDIT: Sorry i didn't read that you already had two heaters up and running. If you add the third 2000 watt one, like i said 14/2 with a 15 amp double pole would be my option. More volts = less amps and smaller wire.

I'd like to use 12/2 wire and a 20 amp dbl pole breaker for my two 4000 watt heaters. But drawing 16.6 amps is just over 80% load of a 20 amp breaker. And is the reason why I'm told to use a 30 amp breaker and 10/2 wire. Thoughts?

 

[yeldogt]

I had to have each of my heaters on separate double beakers as they considered them different loads. I was on the other hand allowed to have two baseboard units in another small room connected together as they were controlled by an individual wall thermostat.

Make sure you check out the codes -- they get complicated ... but doing it correctly is often not much more expensive

 

[dimarcelli]

Either way is okay. 16.6 amps is 83% load on a 20 amp breaker, which is negligible. If i remember correctly, the 80% rule is applied for continuous loads. (items that are on for longer than three hours at a time) If i already had the 12/2 laying around, yeah i would use it. If you're running a new line, then honestly i would probably use 10/2 just so that i could upgrade my heater in the future. I guess what im trying to say is that, if the heaters don't run longer than three hours, and you know you'll keep them, 12/2 is fine.