Installation of Dayton G73 Heater with Cutoff Switch and Thermostat

[Zane]

I figured I would try and make my first post on this forum one that might help anyone down the road who is looking for some further detail on hooking up a Dayton G73 heater. Specifically with an optional cutoff switch and a remote line voltage thermostat.

First I would like to say I gathered a ton of knowledge from Stargeezers original post HERE. Next is a standard disclosure: I am NOT an electrician and if you have any doubts on wiring contact a licensed electrician to validate your work.

This is the list of items I purchased to do the job:
#10 2/1 Romex wire (Black, White & Ground)
30 amp double pole 240v breaker
30 amp double pole 240v switch (Looks like a standard light switch bit its not)
Dayton Single pole line voltage thermostat #4PU49
Conduit, Boxes, Connectors, etc…

To try and simplify things I’m going to break the wiring down into two different runs of 2/1 Romex wire, “Run #1” and “Run#2 thermostat”

(Run #1) Run #10 2/1 Romex wire from the Panel to the placement of your 30amp 240v double pole switch on your wall. This switch will be your power cut off for your set up. You will see in the picture that I had the sheetrock already pulled in this small section to do a repair on some heating and cooling so it made it nice to hide some wires on this small section of the wall. Note: I had not yet secured the wires to the vertical stud before picture was taken. Connect the wires into the switch like you would a normal light switch, keeping black on one side and white on the other and hooking the bare copper wire to the ground on the switch.

From the switch I continued the run of #10 2/1 Romex wire to a junction box near the final placement of the Dayton G73. Leave enough wire to do the final hook up within the heater.

 

[Zane]

(Run #2 Thermostat) Run #10 2/1 Romex wire from the placement of your single pole line voltage thermostat to the junction box that near the final placement of the Heater leaving enough wire to do the final hook up within the heater.

How to hook up Run #2 wires to your Dayton #4PU49 Line Voltage Thermostat: Hook the Black wire to the “Load” side, the White wire to the “Line” side and the bare copper wire to the ground on the thermostat.

You should now have two sets of 2/1 wire coming out of the junction box near where your heater will be placed. Run #1 and Run #2 thermostat” wires…

 

[Zane]

(How to hook up “Run #1” wires inside of heater) Take “Run #1” that comes from your cutoff switch and hook the Black wire to L2, the White wire to L1 in the marked power terminal block within the heater and the bare copper wire to the ground nut within the heater. You have now successfully completed hooking up "Run #1" that supplies the main power to the heater

(How to hook up “Run #2" Thermostat inside of heater) Look inside of the Dayton heater and locate the black wire that runs from the Power terminal block to the back of the turn dial thermostat that is found on the front of the heater. Once you find that wire disconnect it (cut it) from the factory thermostat and connect it using a wire nut to the White “Line” wire coming from “Run #2 Thermostat”. There is another wire that is connected to the back of the turn dial thermostat located on the front of the heater that goes to another terminal board that you can see. Disconnect (cut) that wire from the factory thermostat and connect it to the Black “load” wire from “Run #2 Thermostat” using a wire nut. You have now successfully bypassed the factory thermostat and there should be NO wires connected to the factory thermostat.

What I thought would be helpful to others was to show a wiring diagram of exactly how things are wired. Once you see it, it’s fairly clear and simple. Sometimes pictures are worth more than words. Again, I’m not electrician so feel free to provide feedback as I would prefer the positive or constructive feedback to make this a valuable thread to others in the future.

 

[Zane]

Attached are a few pictures of the heater installed.

 

[Zane]

I had some extra steel channel lying around and welded up the wall mount bracket. I used the factory bracket that connects to the sides of the heater, but keeping true to how I tend to go overboard on things I added a cross bar to bolt the brackets together to reduce movement and beef things up. I am also able to adjust the direction of the heater from left to right if needed via the center pivot point.

 

[BL50]

Very informative post ... thank you. How much area are you heating with your G73?

 

[NoSloCoupes]

Since this is at the top, anyone had the thermostat burn up? I bought mine this year in January, it quit working not long after. Since it was in a space not used often, i just killed the breaker and didn't mess with it until last week. I finally opened it up one of the wires was burnt/melted. Called grainger and they said they'd had problems with them doing just that...so i've got a new one on the way under warranty.

 

[Matt M PA]

Nice write up. I installed one of theses number of years ago in my attached. I just use the knob on the front...but like the idea of the separate thermostat.

 

[Falcon67]

That's a good write up. The thing I'd add is that your setup works well when the heater is close to the t-stat. Move the t-stat very far and the cost of 10-2 wire becomes so great that a 24V t-stat, contactor and transformer get cheap real quick. About $65 right now for 50' of wire at Lowes.

 

[Zane]

That's a good write up. The thing I'd add is that your setup works well when the heater is close to the t-stat. Move the t-stat very far and the cost of 10-2 wire becomes so great that a 24V t-stat, contactor and transformer get cheap real quick. About $65 right now for 50' of wire at Lowes.

Chris, You are 100% correct. I really wanted to have the thermostat near the center of the garage, but the cost of wire is so much right now it was not worth it.

 

[Zane]

Very informative post ... thank you. How much area are you heating with your G73?

My garage space is a residential 3 car garage.

 

[sarman47]

Great write up. Good info. I am still trying to decide what to install in my 2 car garage. Need something to take the chill out this winter.

 

[Cobra6]

Thanks for posting this - I am about to run the circuit for a Dayton heater.

BTW - Romex prices dropped some again at Home Depot last week - you can get 250 feet of 10/2 NM-B for about $136

 

[mebedave]

I have 12' ceilings and I'm looking into a G73 for my 40x40 heated section of shop walls R30 ceilings R50 I just what to keep the chill away like in the 50's do you guys think one G73 would work well for this? Do you have to mount the unit so high off the floor, what would be a good height to keep heat down low as possible (heat raises I'd like to get the heat source down as low as possible) but high enough from the floor/work bench to protect against flammable fumes. I assume that's why these heaters are mounted high, right? How far away from flammables?

 

[Cobra6]

Take a look at the first page of the G73 manual - it has some mounting instructions with recommended min/max height and mounting distances from the wall.

http://www.heater-home.com/manuals/G73.pdf

 

[Easterlake]

Thanks for the post. Hung mine yesterday and will wire it in the next week or so. 70's the next day or so but that will not last.

 

[1jjpop]

I have G-73 heater mounted in my 2 car shop{ with 7' sidewalls ,very well insulated,no windows,& insulated doors] the heater keeps kicking on & off. May be a thermostat mounted on the wall, would help keep it working better... What do you think??????

 

[Stargeezer]

I have G-73 heater mounted in my 2 car shop{ with 7' sidewalls ,very well insulated,no windows,& insulated doors] the heater keeps kicking on & off. May be a thermostat mounted on the wall, would help keep it working better... What do you think??????

Yes that would be a better control method. Or, you might try using a powerful fan of some sort to move the heated air around the workspace so that the heat doesn't stack up near G73 and trigger internal T-Stat. Try the fan, and if not great-then add remote T-stat and use a fan..

 

[brucer]

i'm no electrician. kind of dumb when it comes to wiring and such.. i can do basic 220v and 110v wiring, thats about my extent of wiring..

being your using a 30amp breaker, why is the thermostat your using only rated at 22amps?

 

[Zane]

I'm no electrician either as stated. Someone might be better able to explain, but what I can say is that the single pole thermostat is only using one leg of the 220v and it is what was recommended to me by Dayton for this application.

 

[jvitez]

i'm no electrician. kind of dumb when it comes to wiring and such.. i can do basic 220v and 110v wiring, thats about my extent of wiring..

being your using a 30amp breaker, why is the thermostat your using only rated at 22amps?

I'm no electrician either as stated. Someone might be better able to explain, but what I can say is that the single pole thermostat is only using one leg of the 220v and it is what was recommended to me by Dayton for this application.

Sorry, no. Ohms Law: watts divided by volts= amps. It's a 5000 watt heater.

Therefore, 5000 watts divided by 240 volts= 20.83333333 amps, so a 22 amp thermostat rated for a motor load is fine.

Why a 30 amp breaker? Because the NEC says you need to upsize the calculated amperage by 25% or 1.25 times if it's a continuous load, like lights or heat. So 20.83 X 1.25= 26.04 amps. The next highest amperage breaker is 30 amps, therefore a 5000 watt 240 volt heater needs a 30 amp breaker and 10 gauge wire.

 

[brucer]

Sorry, no. Ohms Law: watts divided by volts= amps. It's a 5000 watt heater.

Therefore, 5000 watts divided by 240 volts= 20.83333333 amps, so a 22 amp thermostat rated for a motor load is fine.

Why a 30 amp breaker? Because the NEC says you need to upsize the calculated amperage by 25% or 1.25 times if it's a continuous load, like lights or heat. So 20.83 X 1.25= 26.04 amps. The next highest amperage breaker is 30 amps, therefore a 5000 watt 240 volt heater needs a 30 amp breaker and 10 gauge wire.

thanks jvitez,

 

[Todd.Brock]

Ok, so I bought a six foot liquid tite whip to use from the j box to the heater. What size did you use to fit 6 #10 conductors( power and thermostat). Mine has three conductors in it with the fittings. they are half inch fittings.... Just curious as I get more into this install. Thanks for the help !

 

[radchad3]

I also have the G73 mounted in my 3 stall residential garage. So far I have really liked it! I keep the thermostat on low and it seems to keep my garage around 45. I also purchased the thermostat mentioned by the OP but its lowest setting is 50 degrees. It seems like the G73 t-stat will go below that so at night I can keep it at around 40 when it is below zero to save some money. For my garage the G73 is slightly under-sized and I am afraid if I add the remote t-stat the thing will always be on as the lowest setting is 50. Any thoughts on this?

Chad

 

[DustynF]

Chad,

I am curious what are the dimensions of your garage?

 

[radchad3]

I am about 800 square feet, not sure on the exact dimensions. My ceilings are 12-13 ft.

 

[DustynF]

Chad,

I have about 960 sq feet with 8 foot ceilings. I bought the Fehrenheit model so I will be anxious to see how it keeps it warm.

 

[royalton10]

Here are pictures of my G73 heater along with thermostat and cutoff switch

 

[radchad3]

Hi Dustyn, should do pretty well in that space. Again, it will be a little under powered. It isn't gonna bring your space up to 80 degrees but it should be enough to take the "cold" out of the room for sure. Let us know how it works! Chad

 

[MattMac123]

Would a double pole tstat elimnate the need for the switch? It was my understanding that a double pole has a "positive off", so when turned all the way down, power would be cut off to the heater.

 

[jvitez]

Yes it would. My understanding, though I'm under the Canadian not National Electrical code: if the circuit breaker is within line of site of the heater, it can be hard wired and the breaker itself used as a disconnect. If not visible within line of site, you'll need another means of disconnect: either hard wired with a switch, or a plug/receptacle arrangement like a twist-lock plug. Would a double pole thermostat be acceptable as a disconnect if the heater is not within line of site of a subpanel? If it's being inspected, the inspector will have the final say.

NEC pros please chime in.

 

[MRoho]

Dustyn / Chad / Royalton: I'm thinking of purchasing a G73 for my 20x20 insulated garage with 10 ft ceilings, do you have any update on how your heater is working with temperatures around freezing? Could you get it up to around 70°F/20°C, if so hwo long would it take you if it was around freezing?
Thanks in advance.
Mike

 

[Charles (in GA)]

Yes it would. My understanding, though I'm under the Canadian not National Electrical code: if the circuit breaker is within line of site of the heater, it can be hard wired and the breaker itself used as a disconnect. If not visible within line of site, you'll need another means of disconnect: either hard wired with a switch, or a plug/receptacle arrangement like a twist-lock plug. Would a double pole thermostat be acceptable as a disconnect if the heater is not within line of site of a subpanel? If it's being inspected, the inspector will have the final say.

NEC pros please chime in.

I would think the thermostat, even if double pole, would not be acceptable. A 30 amp rated double pole "light switch" would do the trick easy enough.

Charles

 

[Zane]

Would a double pole tstat elimnate the need for the switch? It was my understanding that a double pole has a "positive off", so when turned all the way down, power would be cut off to the heater.

If you place a double pole line volt thermostat in, it will shut power down to both the heating element and the fan preventing the fan from cooling the heating element down once the unit has gotten the room to the desired temp.

The set up that has been drawn out in this thread allows you to shut full power off to the entire unit with the 30 amp rated double pole "light switch" when needed. The single pole line volt thermostat only shuts power off to the heating element and you maintain power to the fan, that by design, will shut down on its own once the heating elements has cooled.

 

[innkeeper]

here is a TPI Heater 13,000-19,000btu works the bomb...Innkeeper, Upstate, New York..

 

[twohaggard]

i just orderd a g73 an i dont really know to much about wiring. i been searching and reading your post. is there anything wrong with just useing the t-stat on the heater the way it comes and just putting a on/off switch on the wall so i can just set the t-stat where i want it, an when i want heater on just flip the on switch when i go out in my garage?

 

[jvitez]

Twohaggard: nothing wrong at all. Thats exactly how the manufactuerer made it. Its only us perfectionistic garage lovers that make things more complicated.
You may not even need a switch if you're within the line of site of the circuit breaker controlling the heater. If you want to only heat intermittently a switch is a good idea though.

 

[twohaggard]

im in the line of site with the breaker i just hear flipping the breaker as a on off switch wears it out faster.

 

[innkeeper]

here is a TPI Heater 13,000-19,000btu works the bomb...Innkeeper, Upstate, New York..

I was going to buy the G73, but the CFM on the TPI unit was higher, the cost to my door was alot less.. $248.00 to my front door. I also installed a double poll switch with a inline thermastat, and after two or three days found the unit always runing.. Checked the temperture at the inlne therm with a laser thermomater and it was hot about 80 deg, took the inline therm out and wired it straight through to the unit and now I'm using the thermastate in the unit, almost at the lowest setting, I'm heating a 500sq ft 1 1/2 car Garage with 14' ceilings and insulated also insualled a 36" ceiling fan it is in winter mode and helps move the levals of air around. the temp is constant 62 the unit runs maybe 10mins an hr, evevything else is fine ...
The most diffacult part is getting your core temp set and then manitianing it to get the best efficency out of it.. Hope this helps!!!!

 

[Falcon67]

im in the line of site with the breaker i just hear flipping the breaker as a on off switch wears it out faster.

Never had that issue. Just use the t-stat in the heater, works fine. I never turn my breaker off, just turn off the t-stat on the heater.

FWIW - I have my G73 powered up and I also use a dual burner Mr Heater. The G73 is 17K BTU and the Mr Heater runs about 25K btu. I can get my 960 sq/ft to mid 60s in about 2 hours with the outside temp in the 30s and the building sitting cold overnight. Now - that's with ZERO insulation or any ceiling in the building. Bare walls and rafters. And don't forget the 5 each 10" vent holes in the roof designed to let attic heat out. HardiPanel gets damn cold sitting overnight. Sunday it was high 40s, barely 50, no sun and a north wind. The G73 kept the place around 65F when set on LO and pointed towards the building center. It barely cycled, but it keep up the temp. Once the outside temp falls back into the 40s the heater starts losing ground.

I have no doubt that once I get the ceiling in and the place insulated that the G73 will work well enough by itself. With both, it'll get toasty in maybe 30 minutes. The thing works surprisingly well.