open-type
hermetic
semi-hermetic
all the above
第1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2题：
insufficient condenser cooling water
excessive condenser cooling water
air in the refrigeration system
excessive refrigerant in the system
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 compressor oil
warm food in the refrigerator
excessive condenser cooling water
a shortage of refrigerant
第5题：
overheated compressor bearings
excess lube oil viscosity
carbon deposits on the compressor piston rings
wax crystals forming in the lubricant
第6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7题：
flooding back
superheating
overflowing
recycling
第8题：
Low compressor head pressure in a refrigeration system can be caused by ___.
A.insufficient condenser cooling water
B.excessive condenser cooling water
C.air in the refrigeration system
D.excessive refrigerant in the system
第9题：
frequently grounding out
frequently starting and stopping
running too fast
running too slow
第10题：
Suez Canal searchlight, air compressor and air conditioning compressor
Air compressor, boiler blower and refrigeration plant
Boiler blower, Suez Canal searchlight and refrigeration plant
Suez canal searchlight, air compressor and boiler blower