Heat pump system compressor fault detector

Claim 1

A compressor fault detection and control system (hereinafter "fault detection system") for a reverse cycle refrigeration system (hereinafter "system") for heating and cooling an enclosed space wherein said system comprises refrigerant compression means, refrigerant compression control means, an indoor coil, an outdoor coil, and refrigerant conduit means connecting said compression means and said coils, said fault detection system comprising: outdoor coil temperature sensing means (hereinafter "TODCS") having an output indicative of outdoor coil temperature (hereinafter TODC"); compressor discharge temperature sensing means (hereinafter "TDSCHS") having an output indicative of the temperature (hereinafter "TDSCH") of the refrigerant discharged from said refrigerant compression means; and temperature sensing means (hereinafter "STAT") having an output indicative of a demand for heating or cooling of the enclosed space; and controller means having operative connections to said TODCS, TDSCHS, and STAT so as to receive the outputs thereof, said controller means including circuit connect-disconnect means selectively interconnecting said STAT output to said refrigerant compression control means whereby when said STAT output is connected thereto said compression means is enabled to operate and when said STAT output is disconnected therefrom said compression means is inhibited from operating, said controller means also including timing means and means for comparing the value of TDSCH and the value of TODC plus a preselected constant K 1 , and said controller further being characterized by being adapted to inhibit said compression means from operating if, after a preselected time interval as measured by said timing means, the value of TDSCH is less than the value of TODC plus said predetermined constant.