increase the amount of cooling water to the condenser
decrease the amount of cooling water to the condenser
add more refrigerant to the system
remove some refrigerant from the system
第1题:
If the head pressure of a reciprocating refrigeration compressor is excessive
A.the relief valve should open before the high pressure cutout
B.the relief valve should open and allow the excess refrigerant to flow to the receiver
C.the high pressure cutout switch should operate before the relief valve opens
D.you should close the discharging valve
第2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:
insufficient condenser cooling water
excessive condenser cooling water
air in the refrigeration system
excessive refrigerant in the system
第5题:
In the refrigeration system, a shortage of refrigerant is indicated by
A.the compressor short cycling on high pressure cut out switch
B.high suction pressure
C.high head pressure
D.bubbles in the sight glass
第6题:
When adding oil to a refrigeration system, precautions must be taken to ensure that
A.the compressor suction pressure is not too high
B.all air is purged from the pump and charging fittings
C.the high pressure cutout switch is held open to prevent accidental starting
D.the condenser is completely shutdown first
第7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:
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10题:
flooding back
superheating
overflowing
recycling