The place this is used is to fill the spot market for Outdoor Coil Sensor that would form part of a defrost circuit on an outdoor Condenser coil.
Most SunPump SP 2.2 models do not offer a Condenser Coil like would be standard for an Air to Air heat pump, therefore the sensor spot is missing.
The raw part above can be fastened to early SP 2.2 under the sensor array screw terminals.
However most newer SP 2.2 in 2015 have a Molex connector already attached for the Coil Sensor position, so the we offer soldered Resistors that can be snapped in for faster in the field service. SunPump recommends your Service Technician ask for a few of these parts for his tool box.
