I have a Rheem 10 seer heat pump heating my house. Located in the same compartment as the compressor is an electrical device that is not hitched up to anything. The device is connected to the smaller of the two copper lines going into the heat pump by a small sensing line. Coming out of the device are two 18 ga wires. The device is made by Invensys and has a part # MG27-1038. What is this device?