Patent ID: 7444824

Claim:
A unitary control for operating at least the condenser fan and compressor of a climate control apparatus, the unitary control comprising: at least one compressor relay having contacts for connecting power to a compressor motor; at least one condenser fan relay having contacts for connecting power to a condenser fan motor; at least one sensor for sensing a current across the contacts of the at least one compressor relay; and a microprocessor in communication with the at least one sensor, the microprocessor being configured to signal the at least one compressor relay to close the contacts for connecting power to the compressor motor when a thermostat requests operation of the unitary control, wherein the microprocessor responds to a sensed current across the closed contacts that is below a minimum threshold by signaling the at least one compressor relay to open the contacts for disconnecting power to the compressor; wherein the microprocessor is further configured to signal the at least one compressor relay to open the contacts for disconnecting power to the compressor motor when the thermostat requests discontinued operation of the unitary control, where upon requesting discontinued operation the microprocessor responds to a sensed current across the contacts indicating that the contacts are not open by initiating a response action.