The refrigeration system low pressure cutout switch is actuated by______.A.an electric system managerB.a sensing bulb at the tail coil of the evaporatorC.pressure changes in the suction lineD.failure of the king solenoid valve
The refrigeration system low pressure cutout switch is actuated by______.
A.an electric system manager
B.a sensing bulb at the tail coil of the evaporator
C.pressure changes in the suction line
D.failure of the king solenoid valve
相关考题：
If the head pressure of a reciprocating refrigeration compressor is excessiveA.the relief valve should open before the high pressure cutoutB.the relief valve should open and allow the excess refrigerant to flow to the receiverC.the high pressure cutout switch should operate before the relief valve opensD.you should close the discharging valve
When adding oil to a refrigeration system, precautions must be taken to ensure thatA.the compressor suction pressure is not too highB.all air is purged from the pump and charging fittingsC.the high pressure cutout switch is held open to prevent accidental startingD.the condenser is completely shutdown first
Low compressor head pressure in a refrigeration system can be caused by ___.A.insufficient condenser cooling waterB.excessive condenser cooling waterC.air in the refrigeration systemD.excessive refrigerant in the system
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?A.A shortage of liquid refrigerant.B.Excessive frost on the evaporator.C.Excessive condenser cooling water.D.Insufficient condenser cooling water flow.
The sensing line for the low pressure cutout switch to a refrigeration system is located ______.A.in the chill box(冰箱)B.before the receiverC.on the suction side of the compressorD.on the discharge side of the compressor
单选题Low compressor head pressure in a refrigeration system can be caused by（）.Ainsufficient condenser cooling waterBexcessive condenser cooling waterCair in the refrigeration systemDexcessive refrigerant in the system
单选题In a direct expansion type multi-box refrigeration system, the compressor is set up to cycle on and off by the（）ApressurestatBhigh pressure cutoutCsolenoid valveDlow pressure cutout switch
单选题The refrigeration system low pressure cutout switch is actuated by （）.Aan electric system managerBa sensing bulb at the tail coil of the evaporatorCpressure changes in the suction lineDfailure of the king solenoid valve
单选题The device used for low-pressure control and high-pressure cutout on a compressor is called a（）AcutoutBpressure controllerCcontroller switchDcutout switch
单选题If a large difference exists between the compressor discharge pressure and the pressure corresponding to the existing condensing temperature in a refrigeration system, you should（）.Aincrease the flow of the cooling water through the condenserBadjust the high pressure cutout to maintain the desired pressureCopen the hot gas bypass temporarily to reduce capacityDpurge non-condensable gases to reduce the excess pressure
单选题When adding oil to a refrigeration system, precautions must be taken to ensure that （）.Athe compressor suction pressure is not too highBall air is purged from the pump and charging fittingsCthe high pressure cutout switch is held open to prevent accidental startingDthe condenser is completely shutdown first
单选题If a refrigeration compressor is short cycling on high head pressure, you should （）.Apurge the condenser if the waterside is dirtyBcheck for proper water flow through the condenserCincrease the high pressure cutout settingDreduce the cooling water flow
单选题If a refrigeration compressor were short cycling on the low pressure cutout switch, the probable cause for this might be the （）.Asystem was overcharged with refrigerantBhigh pressure switch was improperly adjustedCexpansion valve strainers were fouledDsuction valves were leaking slightly
单选题If a refrigeration crankcase compressor were short cycling on the low pressure cutout switch, the cause might be that the （）.Asystem was overcharged with refrigerantBsystem was low on refrigerantCsuction valves were leaking slightlyDrelief valve was leaking slightly
单选题If the compressor runs continually, the cause might be the（）Ahigh-pressure cutout switch is jammed openBlow-pressure switch is jammed shutCthermal bulb is not operating properlyDscale trap is clogged
单选题Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?（）AA shortage of liquid refrigerantBExcessive frost on the evaporatorCExcessive condenser cooling waterDInsufficient condenser cooling water flow
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 （）.Asystem is low on refrigerantBhigh pressure cutout switch is improperly adjustedCdischarge valves are leaking slightlyDdischarge valves are leaking excessively
单选题If the head pressure of a reciprocating refrigeration compressor is excessive, （）.Athe relief valve should open before the high pressure cutoutBthe relief valve should open and allow the excess refrigerant to flow to the receiverCthe high pressure cutout switch should operate before the relief valve opensDyou should close in on the suction valve
单选题What separate the high pressure side from the low pressure side in a refrigeration system?（）ACondenser and thermal expansion valveBKing and solenoid valvesCCompressor and thermal expansion valveDCondenser and solenoid valve
单选题The compressor in an air-cooled condensing refrigeration system is short cycling on the high pressure cutout switch（）Asystem is overcharged with refrigerantBsystem is low on refrigerantCdischarge valves are leaking excessivelyDdischarge valves are leaking slightly
单选题One cause of high head pressure occurring in a refrigeration system can be （）.Ainsufficient cooling water flow to the condenserBa low refrigerant charge in the systemCthe liquid valve is open too muchDhigh evaporator superheat
单选题The refrigerant leaves the evaporator of a refrigeration system as a low pressure （）.Asub-cooled liquidBhigh temperature liquidCoil saturated liquidDsuperheated vapor
单选题The purpose of the refrigeration system low pressure cutout switch is to （）Aprotect the compressor from liquid flood backBprotect the compressor from low discharge pressureCstart and stop the compressor upon system demandDstart the compressor after a drop in the evaporator pressure
单选题The sensing line for the low pressure cutout switch to a refrigeration system is located （）.Ain the chill boxBbefore the receiverCon the suction side of the compressorDon the discharge side of the compressor
单选题Constant superheat is maintained at the evaporator outlet of a refrigeration coil by a（）Asolenoid valveBlow pressure cutout switchCking valveDthermal expansion valve
单选题The low pressure side of a refrigeration system is considered to exist from the （）.Aexpansion valve to the compressorBreceiver to the expansion coilCexpansion valve to the evaporatorDcondenser to the expansion valve
单选题Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）AThermal expansion valve frozen openBSuction gas heat exchanger bypassedCCondenser clogged or fouledDHigh pressure cutout switch inoperative