摘要 |
In a transport refrigeration system of the type adapted to provide either heating or cooling, loss of refrigerant is detected by first and second sensors 58 and 60 located upstream and downstream, respectively, of the expansion device 34, and with the downstream sensor 60 also being downstream of the location at which hot gas is injected from line 56 to pass to the refrigerant coil 40 in a heating mode of operation. The arrangement includes means for both determining the mode of system operation, either heating or cooling, and comparing the differential temperatures sensed for determining the departures from ranges of temperatures normally expected with an adequate charge of refrigerant.
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