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单选题
When liquid reaches the compressor of a refrigeration system through the suction line, the condition is called ().
A
flooding back
B
superheating
C
overflowing
D
recycling
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an accumulation of liquid refrigerant in the crankcaseD
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show bubbles
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increase compressor operating speed as necessaryC
allow the motor to turn the compressor opposed only by frictionD
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单选题Refrigerant is normally sub-cooled in a refrigeration or air conditioning system condenser to ().A
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prohibit flashing in the liquid lineC
reduce refrigerant volume in the systemD
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Excessive frost on the evaporatorC
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单选题The refrigeration compressor in a water cooled refrigeration system is short cycling on the high pressure cutout switch, One reason for this could be the ().A
system is low on refrigerantB
high pressure cutout switch is improperly adjustedC
discharge valves are leaking slightlyD
discharge valves are leaking excessively
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单选题When a refrigeration compressor is in the ‘off’ cycle, the thermal expansion valve will().A
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continue to operate as if the system were in operationC
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high pressure vapor lineD
low pressure vapor line
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start and stop the compressor upon system demandD
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create a vapor lock in the liquid receiverC
collect in the condenserD
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liquidB
dry saturated gasC
wet saturated gasD
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insufficient superheatC
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flash gas to form in the liquid lineD
the expansion valve to freeze open
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