Honeywell thermostat switching two separate 24 v systems?

[Bubbles Galore]

Quick question guys, can I run two separate switching wires from a honeywell thermostat if they are not operating on the same 24 volt system? My gut instinct tells me no, but I figured I might as well check.

Thanks in advance

 

[MEP001]

Yes, if the 24V transformers are on the same 120V leg or 240V pair. The easiest way to tell would be to put a voltmeter across both 24V "hot" sides, and the voltage should read zero. If one is supplied 120V and one is 240V it won't work - you might get 48V to one switched device.

 

[Bubbles Galore]

I see. So if both of the 24 volt transformers are fed the same primary voltage, then I will be okay?

 

[MEP001]

It should be; it's worth checking to be safe.

 

[Bubbles Galore]

I ended up getting 50 volts which is why I'm just going to install a second thermostat. Just to clarify, I don't want there to be a signal if the temp is above the setpoint so I should set it up as a "close on rise of temperature" correct?

 

[MEP001]

No, "close on rise" closes the circuit and sends power when the temp is above the setpoint.

For about $10 you could add a micro DPDT relay to split the switch for two circuits.