Operation) Questions With Complete Solutions
Refrigeration control can be achieved by regulating the flow of
refrigerant to the evaporator and also by ______________.
a. increasing the brine concentration
b. regulating the output of the compressor
c. removing refrigerant from the system
d. increasing the level of the receiver
e. regulating the level of the condenser
B
The starting and stopping of the compressor is normally done
automatically by means of __________________.
a. a pressure limiting device
b. an automatic low pressure cut-out
c. either a temperature actuated control or a pressure actuated
control
d. a rheostat
e. a heat sensor in the evaporator
C
Condenser cooling water is usually controlled by
______________.
a. level controls
,b. cooling tower demands
c. solenoid valves
d. hand operated gate valves
e. the level in the receiver
C
A low-pressure control in a refrigerating system can be used for
_________________.
a. condenser pressure control
b. to start and stop the compressor
c. purging non-condensable gases
d. keeping the receiver pressure from getting too high
e. evaporator pressure control
B
Low-pressure cut-outs are used on refrigeration systems to
_________________.
a. stop the compressor on high pressure
b. stop the compressor when the suction pressure drops too low
c. shut the system down due to non-condensable gases
d. stop the compressor when charging the system
e. stop the compressor when the discharge pressure is too low
B
Pressure relief devices may be _____________________.
a. safety valves and pressure limiting devices
, b. low pressure cut outs and rupture members
c. relief valves, fusible plugs or rupture members
d. charging safety equipment
e. high & low level cut offs
C
An oil pressure failure switch is used to ______________.
a. prevent damage to the compressor due to inadequate
lubrication
b. add oil automatically to the compressor
c. warn the operator of low oil
d. close the expansion valve if the oil pressure gets low
e. prevent damage to the condenser due to inadequate oil level
A
The oil separator is always inserted in the system
__________________.
a. to prevent oil logging
b. in a cool pot
c. discharge line
d. suction line
e. the bottom of the evaporator
C
Oil separators and traps on an ammonia system
_________________.