NEED HELP for Solar Furnace

Discussion in 'General Electronics Chat' started by ModelAFan01, Jun 26, 2012.

  1. ModelAFan01

    Thread Starter New Member

    Jun 26, 2012
    I'm creating a Solar Furnace and I'd like to include a connection where thermostat can connect.

    I know the circuit must include a step-down transformer from 115VAC to 24V (24V goes to the thermostat), relay, blower motor, and a defrost board/defrost coil.

    1st problem - Thermostat. The thermostat needs to be wired up like below.
    R- 24V to Thermostat.
    W- Heat Signal
    B- Common. (Goes to Common Leg of Transformer, Secondary Side)
    Y- Cooling. Unused
    G- Blower. Used in "FAN ON" position

    How can I wire the unit up to kick the blower on when a call for heat is established by the thermostat, or the "FAN ON" switch on thermostat is calling for blower to come on.

    2nd problem- How can I create a defrost switch that will engage a defrost coil that will warm up and heat the heat exchanger and assist in heating when the thermo-couple on the outside unit senses that it's below 32*F? The more basic, the more better. :D

    Any help is appreciated. I'd like to give Thanks in advance to anyone who helps.