单项选择题
An excessive charge of refrigerant in an air-cooled refrigeration system can cause ().
A.oil foaming in the compressor
B.higher than normal suction and discharge pressures with a higher box temperature
C.higher than normal discharge pressure with a normal box temperature
D.the compressor to run continuously
相关考题
-
单项选择题
When the steering gear is in operation, you should ().
A.check hydraulic oil levels every hour
B.check the rams for overheating
C.check for excessive oil leakage from rams
D.drain water from telemotor cylinders each watch -
单项选择题
The oil in a cargo winch gear box should be sampled periodically to ().
A.prevent the gear box from leaking
B.prevent the oil from becoming inflammable
C.make sure it has not become contaminated
D.make sure the motor bearings are lubricated -
单项选择题
A spur gear pump should be operated with the discharge valves ().
A.slightly opened
B.throttled
C.fully opened
D.halfway opened
