CONTRACTOR
Figure 8B - Typical wiring for a humidifier in a single-speed air mover application without air conditioning (switching through a G contactor).
Wiring the Fan Switch
For heat pump installations, because of the near-continuous operation of the system air mover, we suggest that installation of a fan sail switch or Skuttle A50 relay be the only additional wiring you perform.
The switch or relay needs to be wired in series with the low-voltage humidity control circuit in order to allow operation of the humidifier during fan operation only (see “NOTE” immediately following this paragraph). In most cases, the humidifier will operate in conjunction with the system air mover to adequately humidify the home.
NOTE: Due to the wiring complexity and multiple variations of heat pumps, it is impossible to provide appropriate diagrams. If you plan for the humidifier to control air mover operation, it is the responsibility of the installing contractor to design a safe control circuit by following diagrams provided with the equipment.
