Ranco C12-2001, Outdoor Ambient Sensor for Heat Pump, -1F to 63F

Resistance Heat Thermostat for Heat Pumps

Ranco's C12-2001 control is an adjustable thermostat which "holds back" additional stages of supplemental heat until the outdoor temperature falls below the control's setpoint.  There are many ways in which the control can be wired into the system.  However, the C12-2001 is typically wired though the relay circuit in conjunction with the indoor thermostat.  Most indoor thermostats used with heat pumps will complete a circuit to the supplemental heat if the indoor temperature drops approximately 2°F or more below the indoor thermostat's setting.

The "C12" series utilizes a SPDT snap-action switch.  Terminal numbers 1 and 2 are normally closed and open with a decrease in temperature.  Terminal numbers 2 and 3 close with a decrease in temperature.

Switch: SPDT, no off position.
Range: -1°F to 63°F
Differential: 5°F
Capillary: 30" with blub
Full Load: 20 Amps at 120/240VAC
Includes knob.