A.dead band action
B.neutral zone action
C.range
D.on-off action
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A.cavitation
B.electrolysis
C.abrasion
D.corrosion
A.the relief valve should open before the high pressure cutout
B.the relief valve should open and allow the excess refrigerant to flow to the receiver
C.the high pressure cutout switch should operate before the relief valve opens
D.you should close in on the suction valve
A.cause of salt contamination
B.location of salt water contamination
C.chemical makeup of feed-water
D.level of alkalinity in condensate
A.restriction in refrigerant piping
B.air and non-condensable gases in the condenser
C.water in the refrigerant
D.flooding back of liquid refrigerant from the evaporator
A.A shortage of liquid refrigerant
B.Excessive frost on the evaporator
C.Excessive condenser cooling water
D.Insufficient condenser cooling water flow
最新試題
Which of the following statements is correct concerning heat transfer?（）
The major source of chemical contaminants in hydraulic fluid is （）.
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
When the steering gear is in operation, you should （）.
An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.
The temperature differential occurring between the inlet temperature of the fluid to be cooled and the outlet temperature of the cooling medium in a shell-and-tube heat exchanger is greatest in which of the flow designs listed?（）
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
Which of the listed pumps is NOT a positive displacement pump?（）
If the head pressure of a reciprocating refrigeration compressor is excessive, （）.
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）