ESCO COMMERCIAL REFRIGERATION ACTUAL
EXAM 2 VERSIONS (VERSION A AND B) COMPLETE
ACCURATE EXAM QUESTIONS WITH DETAILED
VERIFIED ANSWERS (100% CORRECT ANSWERS)
/ALREADY GRADED A+
Multiple compressors provide:
a. Positive oil return.
b. Lower humidity in high humidity locales.
c. Capacity control.
d. Zone control. - ANSWER c. Capacity control.
In a dry type (direct expansion) evaporator, liquid refrigerant must boil away as close to
the end of the coil as possible in order to:
a. Operate at high efficiency.
b. Ensure that frost does not accumulate.
c. Sub-cool the compressor.
d. Ensure proper oil return. - ANSWER a. Operate at high efficiency.
The difference between the temperature of the refrigerant boiling in the evaporator and
the temperature at the evaporator outlet is known as:
a. Evaporator superheat.
b. Latent heat.
c. Evaporator sub-cooling.
d. Sublimation. - ANSWER a. Evaporator superheat.
An expansion device that is stuck open will cause:
a. Low suction pressure.
b. A starved evaporator.
c. Excessive superheat.
d. A flooded evaporator. - ANSWER d. A flooded evaporator.
Superheat measurements are best taken:
a. During a hot pull down.
b. At 8ºF to 12°F.
c. During defrost.
,d. With the system operating at design conditions. - ANSWER d. With the system
operating at design conditions.
A technician is checking the superheat on a multi-circuit evaporator and finds one of the
circuits has a superheat that is higher than the others. This could be caused by:
a. A dirty coil.
b. A refrigerant overcharge.
c. Uneven air distribution.
d. A blocked distributor. - ANSWER d. A blocked distributor.
A TEV with an external equalizer is used on:
a. Evaporators with a high pressure drop.
b. Evaporators with a low pressure drop.
c. High temperature applications only.
d. All evaporators. - ANSWER a. Evaporators with a high pressure drop.
Dry type evaporators operate most efficiently with a superheat setting of approximately:
a. 8ºF to 12°F.
b. 13°F to 19°F.
c. 20°F to 30°F.
d. 31°F to 40°F. - ANSWER a. 8ºF to 12°F.
An evaporator used to chill liquids is operating with a normal superheat setting, but the
system is not cooling the product properly. Which of the following is the most likely
cause?
a. Overcharge of refrigerant.
b. Undercharge of refrigerant.
c. The circulator.
d. The TEV. - ANSWER c. The circulator.
What time interval is required between each superheat adjustment?
a. Not less than 1 hour.
b. About 10-15 minutes.
c. At least ½ hour.
d. No time delay. - ANSWER c. At least ½ hour.
When measuring evaporator superheat on a commercial system that has a long suction
line, the pressure reading should be taken at the:
a. Compressor inlet.
b. Evaporator outlet.
c. Condenser outle
, d. Receiver - ANSWER a. Compressor inlet.
A low temperature evaporator used for cooling space or product refrigeration:
a. Is the same as one used for medium or high temperatures.
b. Must have fins spaced closer together.
c. Must be frosted periodically.
d. Must be defrosted periodically. - ANSWER d. Must be defrosted periodically.
Some special applications use a flooded evaporatoroperated full of refrigerant). In order
to maintain the proper level of liquid refrigerant, a ________ type metering device is
used.
a. High side float.
b. Capillary tube.
C. AEV.
d. Low side float. - ANSWER d. Low side float.
A properly functioning condenser will first:
a. Condense, then de-superheat.
b. Sub-cool then de-superheat.
c. Sub-cool, then superheat.
d. De-superheat, then sub-cool. - ANSWER d. De-superheat, then sub-cool.
The effect of an inefficient water cooled condenser will:
a. Act the same as an air cooled condenser.
b. Act different than a air cooled condenser.
c. Always be mixed with incoming medium without being reheated.
d. Seldom be inefficient on commercial equipment. - ANSWER a. Act the same as an
air cooled condenser.
The refrigerant condensing temperature in a water cooled condenser is normally about
_____
higher than the leaving water.
a. 5°F.
b. 10°F.
C. 15°F.
d. 20°F. - ANSWER b. 10°F.
Workable head pressure during periods of low ambient temperature can be achieved by
using:
a. An economizer.
EXAM 2 VERSIONS (VERSION A AND B) COMPLETE
ACCURATE EXAM QUESTIONS WITH DETAILED
VERIFIED ANSWERS (100% CORRECT ANSWERS)
/ALREADY GRADED A+
Multiple compressors provide:
a. Positive oil return.
b. Lower humidity in high humidity locales.
c. Capacity control.
d. Zone control. - ANSWER c. Capacity control.
In a dry type (direct expansion) evaporator, liquid refrigerant must boil away as close to
the end of the coil as possible in order to:
a. Operate at high efficiency.
b. Ensure that frost does not accumulate.
c. Sub-cool the compressor.
d. Ensure proper oil return. - ANSWER a. Operate at high efficiency.
The difference between the temperature of the refrigerant boiling in the evaporator and
the temperature at the evaporator outlet is known as:
a. Evaporator superheat.
b. Latent heat.
c. Evaporator sub-cooling.
d. Sublimation. - ANSWER a. Evaporator superheat.
An expansion device that is stuck open will cause:
a. Low suction pressure.
b. A starved evaporator.
c. Excessive superheat.
d. A flooded evaporator. - ANSWER d. A flooded evaporator.
Superheat measurements are best taken:
a. During a hot pull down.
b. At 8ºF to 12°F.
c. During defrost.
,d. With the system operating at design conditions. - ANSWER d. With the system
operating at design conditions.
A technician is checking the superheat on a multi-circuit evaporator and finds one of the
circuits has a superheat that is higher than the others. This could be caused by:
a. A dirty coil.
b. A refrigerant overcharge.
c. Uneven air distribution.
d. A blocked distributor. - ANSWER d. A blocked distributor.
A TEV with an external equalizer is used on:
a. Evaporators with a high pressure drop.
b. Evaporators with a low pressure drop.
c. High temperature applications only.
d. All evaporators. - ANSWER a. Evaporators with a high pressure drop.
Dry type evaporators operate most efficiently with a superheat setting of approximately:
a. 8ºF to 12°F.
b. 13°F to 19°F.
c. 20°F to 30°F.
d. 31°F to 40°F. - ANSWER a. 8ºF to 12°F.
An evaporator used to chill liquids is operating with a normal superheat setting, but the
system is not cooling the product properly. Which of the following is the most likely
cause?
a. Overcharge of refrigerant.
b. Undercharge of refrigerant.
c. The circulator.
d. The TEV. - ANSWER c. The circulator.
What time interval is required between each superheat adjustment?
a. Not less than 1 hour.
b. About 10-15 minutes.
c. At least ½ hour.
d. No time delay. - ANSWER c. At least ½ hour.
When measuring evaporator superheat on a commercial system that has a long suction
line, the pressure reading should be taken at the:
a. Compressor inlet.
b. Evaporator outlet.
c. Condenser outle
, d. Receiver - ANSWER a. Compressor inlet.
A low temperature evaporator used for cooling space or product refrigeration:
a. Is the same as one used for medium or high temperatures.
b. Must have fins spaced closer together.
c. Must be frosted periodically.
d. Must be defrosted periodically. - ANSWER d. Must be defrosted periodically.
Some special applications use a flooded evaporatoroperated full of refrigerant). In order
to maintain the proper level of liquid refrigerant, a ________ type metering device is
used.
a. High side float.
b. Capillary tube.
C. AEV.
d. Low side float. - ANSWER d. Low side float.
A properly functioning condenser will first:
a. Condense, then de-superheat.
b. Sub-cool then de-superheat.
c. Sub-cool, then superheat.
d. De-superheat, then sub-cool. - ANSWER d. De-superheat, then sub-cool.
The effect of an inefficient water cooled condenser will:
a. Act the same as an air cooled condenser.
b. Act different than a air cooled condenser.
c. Always be mixed with incoming medium without being reheated.
d. Seldom be inefficient on commercial equipment. - ANSWER a. Act the same as an
air cooled condenser.
The refrigerant condensing temperature in a water cooled condenser is normally about
_____
higher than the leaving water.
a. 5°F.
b. 10°F.
C. 15°F.
d. 20°F. - ANSWER b. 10°F.
Workable head pressure during periods of low ambient temperature can be achieved by
using:
a. An economizer.
