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单选题
Moisture in the refrigerant may （）.
A
freeze on the expansion valve seat and reduce the flow of liquid refrigerant
B
emulsify the oil in the condenser
C
freeze in the king valve
D
clog the oil trap
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单选题A pressure drop through the refrigerant liquid line may cause （）.A
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单选题Clouds form（）.A
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单选题The moisture equilibrium chart can be used to determine the（）.A
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考题
单选题Moisture in the refrigerant may （）.A
freeze on the expansion valve seat and reduce the flow of liquid refrigerantB
emulsify the oil in the condenserC
freeze in the king valveD
clog the oil trap
考题
单选题Which of the following may cause that the compressor cuts off on high pressure cutout in a refrigeration plant? （） (1) faulty condensing (2) too few refrigerant (3) high discharge pressureA
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考题
单选题Separation cloths may be used to（）.A
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wrap cargo that leaks from packagingD
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单选题The thermostatic valve has a throttling action, that is to say the valve can（）A
stop the refrigerant from flowingB
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考题
单选题While troubleshooting a refrigeration system for low head pressure, liquid refrigerant flooding back from the evaporator is determined to be the causeIt may be necessary to （）.A
change the expansion valve adjustmentB
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clean the waterside of the condenser
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单选题When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, you should （）.A
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remove some refrigerant from the system
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单选题Hot air can hold（）.A
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more moisture than cold airC
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单选题A sight glass is installed in the liquid line to indicate the condition of the refrigerant charge and may also indicate the （）.A
condition of the expansion valveB
moisture in the systemC
condition of the compressor suction valvesD
condenser temperature
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单选题The presence of bubbles in a refrigeration system liquid line may （）.A
promote refrigerant dehydrationB
be absorbed in the receiverC
cause low condensing pressureD
carry moisture and lead to corrosion
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