网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
单选题
If a refrigeration compressor will not start, the reason may be （）.
A
the pressure regulating valve is not closing
B
an excessive lack of refrigerant in the system
C
badly leaking discharge valves
D
worn piston rings
参考答案
参考解析
解析：
暂无解析
更多 “单选题If a refrigeration compressor will not start, the reason may be （）.A the pressure regulating valve is not closingB an excessive lack of refrigerant in the systemC badly leaking discharge valvesD worn piston rings” 相关考题
考题
If the refrigeration compressor crankcase is sweating, the cause may be due toA.a shortage of refrigerantB.the compressor running continuouslyC.liquid refrigerant returning to the compressorD.the compressor short cycling on the high pressure cutout
考题
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
考题
Sweating of the refrigeration system compressor crankcase is caused by_______ .A.too much superheatB.insufficient superheatC.suction pressure too lowD.excessive refrigerant returning to the compressor
考题
If the suction pressure for an operating refrigeration compressor is below normal, the cause may be ______.A.an excess of liquid refrigerantB.the expansion valve overfeedingC.a fouled compressor suction strainerD.the compressor short cycling
考题
单选题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
考题
单选题If an electric motor driven air compressor fails to start, it may be due to a （）.A
leaking discharge valveB
jammed suction valveC
tripped overload relayD
broken discharge un-loader
考题
单选题When liquid reaches the compressor of a refrigeration system through the suction line, the condition is called （）.A
flooding backB
superheatingC
overflowingD
recycling
考题
单选题Excessive oil foaming in the crankcase of a refrigeration compressor can result in （）.A
overheated compressor bearingsB
excess lube oil viscosityC
carbon deposits on the compressor piston ringsD
wax crystals forming in the lubricant
考题
单选题Short cycling of a refrigeration compressor refers to （）.A
frequently grounding outB
frequently starting and stoppingC
running too fastD
running too slow
考题
单选题Insufficient refrigerant in a refrigeration plant may result in （）.A
high discharge pressureB
frosting of the crankcaseC
high temperature of the overboard waterD
low suction pressure of compressor
考题
单选题If a refrigeration compressor is running continuously without lowering the temperature in the refrigerated space, the trouble may be （）.A
a shortage of compressor oilB
warm food in the refrigeratorC
excessive condenser cooling waterD
a shortage of refrigerant
考题
单选题（）are supplied by main switchboard directly.A
Suez Canal searchlight, air compressor and air conditioning compressorB
Air compressor, boiler blower and refrigeration plantC
Boiler blower, Suez Canal searchlight and refrigeration plantD
Suez canal searchlight, air compressor and boiler blower
考题
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
考题
单选题When a refrigeration compressor is in the ‘off’ cycle, the thermal expansion valve will（）.A
always be wide open when the compressor restartsB
continue to operate as if the system were in operationC
remain open until evaporator pressure equalizes, then close until the compressor restartsD
always be completely closed until the compressor restarts
考题
单选题If the electric motor driving an air compressor fails to start, the cause may be a （）.A
leaking unloaderB
tripped circuit breakerC
control line leakD
defective pop valve
考题
单选题If the refrigeration compressor crankcase is sweating, the cause may be due to （）.A
a shortage of refrigerantB
the compressor running continuouslyC
liquid refrigerant returning to the compressorD
the compressor short cycling on the high pressure cutout
考题
单选题If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.A
refrigerant overchargeB
overfeeding by the expansion valveC
a restricted suction strainerD
due to short cycling of the compressor
考题
单选题If the capacity of the refrigeration compressor is too large, the saturation temperature will （）.A
riseB
fallC
be maintained constantD
None of the above
考题
单选题Excessive oil foaming in the crankcase of a refrigeration compressor at start up can cause（）.A
compressor damage from improper lubricationB
refrigerant absorption by the lubricantC
increased viscosity in the lubricantD
carbon deposit on the compressor suction valves
考题
单选题In the refrigeration compressor the temperature of the vapor is （） by compression.A
raisedB
risenC
reducedD
maintained constant
考题
单选题It should be ensured that only （） vapor is handled by the refrigeration compressor.A
humidityB
dryC
steamD
oil
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
any of (1) and (3)B
any of (1) and (2)C
any of (2) and (3)D
any of (1), (2) and (3)
考题
单选题The purpose of the refrigeration system low pressure cutout switch is to （）A
protect the compressor from liquid flood backB
protect the compressor from low discharge pressureC
start and stop the compressor upon system demandD
start the compressor after a drop in the evaporator pressure
考题
单选题Sweating of the refrigeration system compressor crankcase is caused by （）.A
too much superheatB
insufficient superheatC
suction pressure too lowD
excessive refrigerant returning to the compressor
考题
单选题Excessive oil foaming in the crankcase of a refrigeration compressor is most likely to occur（） when the compressor.A
has continuously for a long periodB
suction pressure is below normalC
oil level is below normalD
starts after a long idle period
考题
单选题A pressure drop in the liquid line of a refrigeration system may cause（）A
the solenoid valve to seizeB
the compressor to huntC
flash gas to form in the liquid lineD
the expansion valve to freeze open
考题
单选题When a refrigeration compressor motor fails to start, the FIRST thing that should be checked for is a （）.A
loose expansion valve control bulbB
low differential setting on the H-PcutoutC
blown fuse in the motor circuitD
faulty suction pressure regulator
热门标签
最新试卷