Automatic fault diagnostic apparatus for a heat pump air conditioning system

摘要

Microprocessor controlled apparatus is provided for automatically diagnosing faults in a heat pump system. Temperature sensors located at strategic points in the system are read periodically in accordance with a preprogrammed diagnostic routine. Temperature measurements preferably representing comparison of two temperature readings that produce temperature differentials outside pre-established tolerance limits are stored with a fault identification representative of the corresponding fault measurement. A service technician can read the fault data from storage by activation of control means for that purpose whereby the nature of the causative fault or faults can readily be determined.