Thermostat for 240v 35amp heater

[Sovereign-1]

Hello GJ,

I have a 240v electric heater on a 35 amp circuit that I use to heat my garage while I am in it. However to make sure things don't freeze in there when the temperatures really go down I would like to put it on a thermostat that would keep it at or above 35 degrees. All of the thermostats that I can find are not rated for 35 amps. Any suggestions on a device that will meet my needs?

 

[wyliesdiesels]

Which model heater?

Most have a low voltage 24v contactor and the thermostat would just cycle the contactor so high current doesnt run directly through the thermostat.

Theres also a recent thread on this same exact topic.

Try the search feature.

 

[matt_i]

I would use a 2 pole definite purpose contactor, can get rated for 40A, with a 24VAC coil voltage. (note its NOT 24 VDC) This will switch 2 legs of 240vac to the heating element.

As suggested use a 24VAC HVAC control transformer to supply the low voltage, the thermostat simply pulls in the contactor coil when heat is needed.

 

[larry4406]

A lot of these type heaters run the fan for a period of time after the stat has been satisfied so as to cool down the elements.

Thus, just don't kill power as your control method if yours is the type where the fan runs after the elements drop out.

 

[Sovereign-1]

Mine is a profusion 6000 watt. I didn't see any provisions for a separate thermostat control.

 

[alfredeneuman]

A lot of these type heaters run the fan for a period of time after the stat has been satisfied so as to cool down the elements.

Thus, just don't kill power as your control method if yours is the type where the fan runs after the elements drop out.

^^^^^^^^^^^THIS IS IMPORTANT^^^^^^^^^^^^^^^

 

[Bert_]

I'm not familiar with the 6000w unit. I know a 7500w version of that heater does use a contactor, and has provisions for external t-stat.

A lot of these type heaters run the fan for a period of time after the stat has been satisfied so as to cool down the elements.

Thus, just don't kill power as your control method if yours is the type where the fan runs after the elements drop out.

I don't think any of these profusion brand heaters are set up this way. All that I have seen the element and fan turn on and off at the same time. OP's could be different like I said I haven't seen a 6kw one

FYI a 6000w heater draws 25 amps so your thermostat only needs to be rated 25A

 

[Sovereign-1]

The manual stated the use of a 35 amp breaker, so that is why I assume the same capacity for the thermostat.

 

[wyliesdiesels]

The manual stated the use of a 35 amp breaker, so that is why I assume the same capacity for the thermostat.

can you post the model number so i can look it up...

EDIT: The 35a breaker is called for because the heater is considered a continous load.(expected to run for 3 hours or more at max load.)

6000w / 240 = 25a * 1.25 = 31.25a round up to next standard size breaker or fuse = 35a.

 

[Sovereign-1]

Profusion PH-960N

 

[wyliesdiesels]

I dont see any provisions for a low voltage thermostat/contactor option built in.

You could use a 25a line voltage rated thermostat double pole(manufacturer states double pole on pg. 5)....

https://www.platt.com/platt-electri...imetal/Cadet/C612-25/product.aspx?zpid=326151

Or...

Use a 40a contactor with a 24v coil and a 24v thermostat along with a 240v/24v control transformer.

 

[Sovereign-1]

Something like this?
https://www.amazon.com/dp/B06X8Z255M/?tag=atomicindus08-20