Lennox Whisper Heat

[Madmarl]

I am tring to hook up a Thermo Mist 2000 humidifier to my Lennox Whisper Heat furnace. The Thermo Mist company has told me that I should hook it up to the fan motor so when the fan runs, the humdifier runs. The problem is that I don't know which wires are for the fan only. Does anyone know which color the wires are to hook this up? Any help would be appreciated.. Thanks

[imeduc]

The best way to do that is get a current sensing relay. All you have to do it slip the blower wire through it. Then any time the blower comes on the humidifier can turn on.

ED

My mistakes dont define me they inform me.

[Madmarl]

Where would I pick one of those up? Would an electronics shop have one or a hardware store? Thanks for the prompt response.

[imeduc]

Electric shop any hvac shop .Johnstone supply , Grainger Co
Where you got the humidifier from will are should have them.

ED

My mistakes dont define me they inform me.

[LazyPup]

It would depend on the amperage requirement for the humidiifier but you might consider installing a second fan relay to power the humidifier and control it from the green wire on the low voltage control circuit.

[Madmarl]

The amperage on the humidifier is .40amps @ 24 volts. It's basically a selenoid to open and close the valve. I was thinking of wiring it from the motor through the transformer that came with it and then to the humidifier. I'm just not sure which wires are to the motor. And which are off when the fan is off. Is that as clear as mud? Thanks for the response.

[imeduc]

There on the Lennox there should be the wire schematic on the blower door and it will show you. Go down in the blower by the motor and you will see what wires are there. Not real sure but white is ground red low, yellow med-low ,Brown med-high ,black high.

ED

My mistakes dont define me they inform me.

[Madmarl]

Thanks for the info. I think going from the motor is the simplest plan. There is minimal current draw from there and the humidifier will only run when the fan is on.I don't want it running with the fan off as it will rust up the furnace.Thanks for all the great help.

[eP]

Hi there.

Usually you want to sync the hum with the low-speed on the blower. Or the lower of the speeds attached, if it's a multi-tap.

Hope this helps.


* HVAC pros visit me at : http://www.mechanicalminds.net *