NATE A/C EXAM #1 QUESTIONS AND
ANSWERS 100% CORRECT
Low airflow over a residential split system air conditioning evaporator can cause
A: Liquid flood-back to the compressor
B: A decrease in compression ratio
C: An increase in suction line superheat
D: Oil logging in the evaporator - ANSWERA: Liquid flood-back to the compressor
A hot liquid line with a low to normal high side pressure is an indication of
A: An overcharged system
B: An undercharged system
C: Air in the system
D: A restricted filterdrier - ANSWERB: An undercharged system
Air and water are directed counterflow so as to
A: Average the flow rate
B: Gain the greatest amount of heat transfer
C: Reach the lowest apparatus dew point
D: Control the humidity - ANSWERB: Gain the greatest amount of heat transfer
As the pressure on a liquid is increased, the vaporization temperature of the liquid
A: Decreases
B: Increases
C: Remains unchanged
, D: Varies - ANSWERB: Increases
An oil separator must be mounted
A: Level
B: Below the compressor crankcase
C: Above the compressor crankcase
D: In the suction line - ANSWERA: Level
Which of the following metering devices controls evaporator pressure?
A: Thermostatic expansion valve
B: Fixed orifice
C: Low side float
D: None of these - ANSWERD: None of these
An automatic expansion valve controls evaporator pressure.
The purpose of the external equalizer on a thermostatic expansion valve is
A: To equalize evaporator pressure drop with respect to the TEV
B: To equalize the evaporator pressure drop
C: To help prevent liquid floodback
D: To allow the high side pressure to equalize to the low side when the compressor
cycles off - ANSWERA: To equalize evaporator pressure drop with respect to the TEV
The higher the MERV rating of a filter-drier, the
A: More efficient the drier at absorbing moisture
B: Less efficient the drier at absorbing moisture
C: Smaller the particles the filter can entrap
D: MERV does not apply to filter-driers - ANSWERD: MERV does not apply to filter-
driers
ANSWERS 100% CORRECT
Low airflow over a residential split system air conditioning evaporator can cause
A: Liquid flood-back to the compressor
B: A decrease in compression ratio
C: An increase in suction line superheat
D: Oil logging in the evaporator - ANSWERA: Liquid flood-back to the compressor
A hot liquid line with a low to normal high side pressure is an indication of
A: An overcharged system
B: An undercharged system
C: Air in the system
D: A restricted filterdrier - ANSWERB: An undercharged system
Air and water are directed counterflow so as to
A: Average the flow rate
B: Gain the greatest amount of heat transfer
C: Reach the lowest apparatus dew point
D: Control the humidity - ANSWERB: Gain the greatest amount of heat transfer
As the pressure on a liquid is increased, the vaporization temperature of the liquid
A: Decreases
B: Increases
C: Remains unchanged
, D: Varies - ANSWERB: Increases
An oil separator must be mounted
A: Level
B: Below the compressor crankcase
C: Above the compressor crankcase
D: In the suction line - ANSWERA: Level
Which of the following metering devices controls evaporator pressure?
A: Thermostatic expansion valve
B: Fixed orifice
C: Low side float
D: None of these - ANSWERD: None of these
An automatic expansion valve controls evaporator pressure.
The purpose of the external equalizer on a thermostatic expansion valve is
A: To equalize evaporator pressure drop with respect to the TEV
B: To equalize the evaporator pressure drop
C: To help prevent liquid floodback
D: To allow the high side pressure to equalize to the low side when the compressor
cycles off - ANSWERA: To equalize evaporator pressure drop with respect to the TEV
The higher the MERV rating of a filter-drier, the
A: More efficient the drier at absorbing moisture
B: Less efficient the drier at absorbing moisture
C: Smaller the particles the filter can entrap
D: MERV does not apply to filter-driers - ANSWERD: MERV does not apply to filter-
driers
