A.run continuously B.not start C.have high discharge pressure D.short cycle on the high pressure switch
单项选择题Which of the following terms could be applied to the simple definition the energy of motion?()
A.Electrical energy B.Thermal energy C.Potential energy D.Kinetic energy
单项选择题The delivery rate of an axial-piston hydraulic pump is controlled by varying the position of the ().
A.sliding block B.pintle C.reaction ring D.tilting box or swash plate
单项选择题Badly leaking refrigeration compressor discharge valves will cause().
A.overfeeding of the expansion valve B.damage to the condenser C.constant running of the compressor D.flooding of the receiver
单项选择题Mechanical energy in transition is referred to as ().
A.horsepower B.work C.heat D.velocity
单项选择题If you change from a low pour point lubricant to a high pour point lubricant in a refrigeration system, ().
A.compressor lubrication will be improved B.oil will not leave the crankcase C.compressor valves will be damaged D.oil may congeal in the evaporator