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 listed pumps is NOT a positive displacement pump?（）
If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump （）.
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.
A salinity indicator is used to determine the （）.
One cause of high head pressure occurring in a refrigeration system can be （）.
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
An excessive charge of refrigerant in an air-cooled refrigeration system can cause （）.
Which of the following statements is correct concerning heat transfer?（）
When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.