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To correct the condition of slugging and flooding back in a refrigeration system, it may be necessary to （）.
A . re-adjust the discharge pressure
B . clean the expansion valve screen
C . add refrigerant
D . adjust the expansion valve
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A liquid indicator sight glass is useful in determining whether or not a refrigeration system is sufficiently chargedIt is generally located in the（）.
A . high pressure liquid line
B . low pressure liquid line
C . high pressure vapor line
D . low pressure vapor line
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The receiver used in a refrigeration system（）
A . stores liquid refrigerant
B . collects non-condensable gases
C . allows refrigerant sub-cooling
D . prevents compressor surging
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The purpose of the purge valve at the top of the condenser in a refrigerating system is to（）
A . remove any air that may accumulate in the system
B . take out unpleasant fumes from the refrigerant
C . vent off excess refrigerant in an emergency
D . permit opening the refrigerating system for cleaning and inspecting
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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
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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 gla
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One cause of high head pressure occurring in a refrigeration system can be （）.
A . insufficient cooling water flow to the condenser
B . a low refrigerant charge in the system
C . the liquid valve is open too much
D . high evaporator superheat
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In a refrigeration system, foaming of the crankcase oil may cause the （）.
A . expansion valve to overfeed
B . compressor to knock
C . water regulating valve to fail
D . crankcase drains to plug
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The effect of high vapor superheat in a refrigeration system, is a/an （）.
A . increased capacity of the compressor
B . more efficient operation of the thermal expansion valve
C . decreased capacity of the compressor
D . loss of receiver capacity
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Crankcase sweating in a refrigeration system is caused by （）.
A . a stuck solenoid valve
B . a shortage of refrigerant
C . too much oil in circulation
D . too much superheat
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Refrigerant entering the compressor of a refrigeration system should be in which of the following conditions?（）
A . Sub-cooled liquid
B . Sub-cooled vapor
C . Superheated vapor
D . Liquid
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A liquid sight flow indicator in a refrigeration system is examined and gas bubbles are noted in motion with the fluid flowThis means （）.
A . the system is fully charged
B . there is air leaking in from the condenser
C . ice crystals are forming in the refrigerant
D . the system contains less than a full charge of refrigerant
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The presence of bubbles in a refrigeration system liquid line may （）.
A . promote refrigerant dehydration
B . be absorbed in the receiver
C . cause low condensing pressure
D . carry moisture and lead to corrosio
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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
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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
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An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.
A . restriction in refrigerant piping
B . air and non-condensable gases in the condenser
C . water in the refrigerant
D . flooding back of liquid refrigerant from the evaporator
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In an operating refrigeration system low on refrigerant, a liquid line sight glass will（）
A . be clear
B . be blue
C . be light green
D . show bubble
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The latent heat of evaporation is dissipated in the （） in a compression refrigeration system.
A . evaporator
B . condenser
C . expansion valve
D . compressor
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A solenoid valve used in a refrigeration system should be installed （）.
A . with the axis of the solenoid horizontal, sensing temperature of the box, and upstream of the thermal expansion valve
B . upright, sensing temperature of the box, and upstream of the thermal expansion valve
C . upright, sensing temperature of the box, and downstream of the thermal expansion valve
D . upright, sensing heat of the tail coil, and upstream of the thermal expansion valve
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The function of （） in a refrigeration plant using Freon is to move moisture from all refrigeration system.
A . filter
B . filter drier
C . heat exchanger
D . air cooler
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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
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A pressure drop in the liquid line of a refrigeration system may cause（）
A . the solenoid valve to seize
B . the compressor to hunt
C . flash gas to form in the liquid line
D . the expansion valve to freeze ope
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Excessive circulation of the lubricating oil with the refrigerant in a refrigeration system will cause______.
A.carbon deposits on the compressor suction valves
B.the evaporator temperature to increase
C.rapid corrosion of the thermal expansion valve
D.no operating problems
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The pressure range between the system cut in and cut out pressures in a refrigeration unit is known as_______.
A.opposing operational drag
B.pressure distribution
C.differential
D.system purge
