-
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 in on the suction valve
-
In a refrigeration system, if the cooling water to the condenser fails, the（）.
A . box temperature solenoid valve will close
B . expansion valve will close
C . compressor will shutdown
D . king valve will ope
-
If a refrigeration compressor will not start, the reason may be （）.
A . the pressure regulating valve is not closing
B . an excessive lack of refrigerant in the system
C . badly leaking discharge valves
D . worn piston ring
-
As the refrigerant passes through the valve orifice, its pressure is reduced and part of the refrigerant turns into （）.
A . liquid
B . oily mixture
C . emulsion
D . vapor
-
To add refrigerant to the low side of an air conditioning system, the refrigerant should be introduced through the （）
A . suction service valve as a vapor
B . suction service valve as a liquid
C . discharge service valve as a vapor
D . charging valve as a liquid
-
In a refrigeration system, the refrigerant absorbs the latent heat of vaporization in the（）.
A . compressor
B . condenser
C . receiver
D . evaporator
-
The refrigerant flows through the evaporator, where it （） heat from the refrigerated space.
A . extracts
B . releases
C . gives no
D . absorbs no
-
If a refrigeration compressor were short cycling on the low pressure cutout switch, the probable cause for this might be the （）.
A . system was overcharged with refrigerant
B . high pressure switch was improperly adjusted
C . expansion valve strainers were fouled
D . suction valves were leaking slightly
-
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
-
In a compression refrigeration plant the refrigerant is under low pressure in the （） and under high pressure in the （）.
A . compressor；condenser
B . condenser；evaporator
C . throttle valve；evaporator
D . evaporator；condenser
-
Which of the listed refrigeration system components keeps the refrigerant circulating through the system?（）
A . Expansion valve
B . Condenser
C . Evaporator
D . Compressor
-
If a large difference exists between the compressor discharge pressure and the pressure corresponding to the existing condensing temperature in a refrigeration system, you should（）.
A . increase the flow of the cooling water through the condenser
B . adjust the high pressure cutout to maintain the desired pressure
C . open the hot gas bypass temporarily to reduce capacity
D . purge non-condensable gases to reduce the excess pressure
-
The component of a refrigerating system in which the refrigerant vaporizes and absorbs heat is known as the （）.
A . condenser
B . vapor generator
C . accumulator
D . evaporator
-
In which of the listed refrigeration system components does superheating of the refrigerant take place?（）
A . Expansion valve
B . Evaporator
C . Drier
D . Receiver
-
Which of the problems listed could be indicated if a sight glass in the refrigerant liquid line is full of bubbles?（）
A . Proper refrigerant charge
B . Faulty expansion valve
C . Insufficient refrigerant
D . Solenoid valve stuck ope
-
In a compression refrigeration cycle, the temperature of the liquid refrigerant experiences its greatest decrease in the（）.
A . evaporator
B . compressor
C . expansion valve
D . condenser
-
To add refrigerant to the high side of an air conditioning system, you should introduce the refrigerant through the （）.
A . discharge service valve as a vapor
B . suction service valve as a liquid
C . charging valve as a liquid
D . condenser purge valve as a vapor
-
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 compressor
-
If a refrigeration compressor is running continuously without lowering temperature as normal in the refrigerator, the trouble may be （）.
A . excessive condenser cooling water
B . warm food in the refrigerator
C . a shortage of refrigerant
D . s shortage of compressor oil
-
If liquid refrigerant accidentally comes in contact with the eyes, （） immediately.
A . rub the eyes
B . irritate the eyes
C . wash the eyes with a heavy boric acid solution
D . obtain medical hel
-
If a liquid sight flow indicator in a refrigeration system shows gas bubbles in motion passing inside of the glass, there is （）.
A . too much refrigerant in the system
B . oil entrained in the refrigerant
C . less than a full charge of refrigerant in the system
D . ice crystals forming in the refrigerant
-
If a refrigeration crankcase compressor were short cycling on the low pressure cutout switch, the cause might be that the （）.
A . system was overcharged with refrigerant
B . system was low on refrigerant
C . suction valves were leaking slightly
D . relief valve was leaking slightly
-
Some chloronated flourocarbon refrigerants may decompose into a toxic irritating gas if it is （）.
A . stored at temperatures below 60 degrees Fahrenheit
B . charged into a system having copper fittings
C . allowed to mix with compressor oil
D . exposed to an open flame or hot surface
-
If you don’t put the milk in the refrigerator，it may__________ ．
A.go by
B.go off
C.go on
D.go back
