Commercial Refrigeration Final Study Guide
Latest Update 2025-2026 90 Questions and 100%
Verified Correct Answers Guaranteed A+
A low pressure control has a "high event" and a "differential setting. The technician
wants the system to "cut-in" at 28 PSIG and cut-out at 2 PSIG, what would the proper
setting be? - CORRECT ANSWER: High event: 28 PSIG, differential: 26 PSIG
A motor can burn-out if the supply voltage is either too high or too low. - CORRECT
ANSWER: True
A R-22 medium temperature walk-in cooler at 95 degree ambient and 30 degree split
should run a head pressure of about ________ ? - CORRECT ANSWER: 278 PSIG
A run capacitor helps a compressor run efficiently by slightly energizing the start
winding. - CORRECT ANSWER: True
A thermostatic expansion valve controls refrigerant flow through the evaporator based
on _______________ . - CORRECT ANSWER: Bulb pressure, evaporator pressure, &
spring pressure
A thermostatic expansion valve controls refrigerant flow to the evaporator based on
____________ . - CORRECT ANSWER: Rate of liquid vaporization, evaporator suction
line superheat, and external equalizer pressure.
Abnormally high subcooling is a sign of ________ ? - CORRECT ANSWER: too much
refrigerant in the condenser
, After the vapor has been condensed into a liquid, what are two causes for the liquid to
flash back into a vapor before it reaches the metering device? - CORRECT ANSWER: A
raise in temperature or a fall in pressure.
Capillary tube systems are normally used for storage of already refrigerated products. -
CORRECT ANSWER: True
During hot pull-down what is the evaporator experiencing? - CORRECT ANSWER:
Starving because the refrigerant is boiling off quickly
Fan cycling controls can respond to what 2 conditions? - CORRECT ANSWER: Ambient
air temperature and head pressure
Fewer fins per inch on an evaporator allows more ice to build between defrost cycles. -
CORRECT ANSWER: True
Good ventilation is important when working around refrigeration equipment because
modern refrigerants ______________ . - CORRECT ANSWER: Are heavier than air and
may displace the oxygen around you
High superheat means your TXV is flooding the coil. - CORRECT ANSWER: False
High temperature refrigeration is that produced by _________ . - CORRECT ANSWER:
An air-conditioning system
Hot gas and electric defrost use the same time clock. - CORRECT ANSWER: True
How can flooded starts be prevented? - CORRECT ANSWER: Install a crankcase
heater or a pump-down solenoid.
Latest Update 2025-2026 90 Questions and 100%
Verified Correct Answers Guaranteed A+
A low pressure control has a "high event" and a "differential setting. The technician
wants the system to "cut-in" at 28 PSIG and cut-out at 2 PSIG, what would the proper
setting be? - CORRECT ANSWER: High event: 28 PSIG, differential: 26 PSIG
A motor can burn-out if the supply voltage is either too high or too low. - CORRECT
ANSWER: True
A R-22 medium temperature walk-in cooler at 95 degree ambient and 30 degree split
should run a head pressure of about ________ ? - CORRECT ANSWER: 278 PSIG
A run capacitor helps a compressor run efficiently by slightly energizing the start
winding. - CORRECT ANSWER: True
A thermostatic expansion valve controls refrigerant flow through the evaporator based
on _______________ . - CORRECT ANSWER: Bulb pressure, evaporator pressure, &
spring pressure
A thermostatic expansion valve controls refrigerant flow to the evaporator based on
____________ . - CORRECT ANSWER: Rate of liquid vaporization, evaporator suction
line superheat, and external equalizer pressure.
Abnormally high subcooling is a sign of ________ ? - CORRECT ANSWER: too much
refrigerant in the condenser
, After the vapor has been condensed into a liquid, what are two causes for the liquid to
flash back into a vapor before it reaches the metering device? - CORRECT ANSWER: A
raise in temperature or a fall in pressure.
Capillary tube systems are normally used for storage of already refrigerated products. -
CORRECT ANSWER: True
During hot pull-down what is the evaporator experiencing? - CORRECT ANSWER:
Starving because the refrigerant is boiling off quickly
Fan cycling controls can respond to what 2 conditions? - CORRECT ANSWER: Ambient
air temperature and head pressure
Fewer fins per inch on an evaporator allows more ice to build between defrost cycles. -
CORRECT ANSWER: True
Good ventilation is important when working around refrigeration equipment because
modern refrigerants ______________ . - CORRECT ANSWER: Are heavier than air and
may displace the oxygen around you
High superheat means your TXV is flooding the coil. - CORRECT ANSWER: False
High temperature refrigeration is that produced by _________ . - CORRECT ANSWER:
An air-conditioning system
Hot gas and electric defrost use the same time clock. - CORRECT ANSWER: True
How can flooded starts be prevented? - CORRECT ANSWER: Install a crankcase
heater or a pump-down solenoid.
