Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

240V heater and low voltage thermostat

AmateurHour
AmateurHour Member Posts: 2
in Thermostats and Controls
Looking for a little confirmation from the experts on this. I have a 5000W DynaGlo heater in my garage and I'm setting it up for external thermostat control. It has a switch and terminal block for external control with a line voltage stat. I'm using an Aube RC840T-240 transformer/relay and an ecobee 3 lite stat. I've attached a sketch of what I think is how this should be wired in order to retain functionality of the internal thermostat as I believe it controls the fan delay start and cool down run.

Thoughts?

Welcome

It looks like you're new here. Sign in or register to get started.
Sign In
Register

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 25,976
    Refer to the wiring diagram which is helpfully printed on the case of the RC840T-240 and the heater's diagram. You can have either the heater's thermostat active or the external one -- but not both.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 17,697
    No. You r not hooked up right.

    Connect the Blue from the RC840T-240 to L2 on the heater
    Connect the Black to #1 terminal external thermostat
    Connect the Red to #2 terminal external thermostat

    Then attach your thermostat
    AmateurHour
  • AmateurHour
    AmateurHour Member Posts: 2
    How does this look?
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 17,697
    looks fine to me
    lbartley1959
  • utility01
    utility01 Member Posts: 1
    edited February 2022
    @AmateurHour : I am doing exactly the same thing as you with a 5000W DynaGlo heater and an Aube RC840T-240 transformer/relay, but with a different thermostat.
    Did your corrected wiring diagram work out successfully?
    Thank you.
  • lbartley1959
    lbartley1959 Member Posts: 1
    I tried both ways and it did not work for me.
  • Jamie Hall
    Jamie Hall Member Posts: 25,976
    Did you wire it in accordance with the Aube wiring diagram?
    https://www.manualslib.com/manual/11515/Aube-Technologies-Rc840t.html
    Note that you have a choice: external thermostat or internal thermostat. NOT BOTH.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Jamie Hall
    Jamie Hall Member Posts: 25,976
    I might add -- you will need a two pole service disconnect for that heater, as the Aube relay only breaks one of the hots, not the other.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England

Welcome

It looks like you're new here. Sign in or register to get started.
Sign In
Register

Welcome

It looks like you're new here. Sign in or register to get started.
Sign In
Register

Quick Links

Categories