单项选择题
A.insufficient condenser cooling water B.excessive condenser cooling water C.air in the refrigeration system D.excessive refrigerant in the system
Which of the problems listed would came the discharge t...
单项选择题Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
A.Thermal expansion valve frozen open B.Suction gas heat exchanger bypassed C.Condenser clogged or fouled D.High pressure cutout switch inoperative
The usual symptoms of cavitation in a centrifugal pump ...
单项选择题The usual symptoms of cavitation in a centrifugal pump is （）.
A.noise and vibration B.an increase in discharge pressure C.an increase in suction pressure D.lifting of the relief valve
One cause of high head pressure occurring in a refriger...
单项选择题One cause of high head pressure occurring in a refrigeration system can be （）.
A.insufficient cooling water flow to the condenser B.a low refrigerant charge in the system C.the liquid valve is open too much D.high evaporator superheat
