system was overcharged with refrigerant
system was low on refrigerant
suction valves were leaking slightly
relief valve was leaking slightly
第1题：
Excessive oil foaming in the crankcase of a refrigeration compressor is most likely to occur when the compressor
A.has run continuously for a long period
B.suction pressure is below normal
C.oil level is below normal
D.starts after a long idle period
第2题：
If the suction pressure at the refrigeration compressor is below normal, the cause can be
A.refrigerant overcharge
B.overfeeding by the expansion valve
C.a restricted suction strainer
D.due to short cycling of the compress
第3题：
If the refrigeration compressor crankcase is sweating, the cause may be due to
A.a shortage of refrigerant
B.the compressor running continuously
C.liquid refrigerant returning to the compressor
D.the compressor short cycling on the high pressure cutout
第4题：
a shortage of refrigerant in the system
air in the system
an accumulation of liquid refrigerant in the crankcase
a shortage of oil in the crankcase
第5题：
If the suction pressure for an operating refrigeration compressor is below normal, the cause may be ______.
A.an excess of liquid refrigerant
B.the expansion valve overfeeding
C.a fouled compressor suction strainer
D.the compressor short cycling
第6题：
If a refrigeration system were short of refrigerant, the condition would result in
A.continuous running of the compressor
B.high suction pressure
C.high discharge pressure
D.short cycling of the compressor on the water failure switch
第7题：
Sweating of the refrigeration system compressor crankcase is caused by_______ .
A.too much superheat
B.insufficient superheat
C.suction pressure too low
D.excessive refrigerant returning to the compressor
第8题：
If a refrigeration compressor is short cycling on high head pressure, you should
A.purge the condenser if the waterside is dirty
B.check for proper water flow through the condenser
C.increase the high pressure cutout setting
D.reduce the cooling water flow
第9题：
sudden evaporation of wax crystals in the lubricant
sudden evaporation of entrapped air in the lubricant
release of refrigerant from the oil/refrigerant mixture
release of dissolved lubricant from the refrigerant
第10题：
add refrigerant to the system
adjust the thermal expansion valve to the proper setting
adjust the float valve to the proper holding pressure
open the hand expansion valve