NATE INDUSTRY COMPETENCY EXAM COMMERCIAL
REFRIGERATION EXAM QUESTIONS WITH ALL CORRECT &
VERIFIED ANSWERS
1. With the condensing pressure and compressor
speed D remaining constant, a decrease in
suction pressure will cause a(n):
a. Decrease in compressor capacity and
decrease in current.
b. Increase in compressor capacity and
decrease in current.
c. Increase in compressor capacity and
increase in current.
d. Decrease in compressor capacity and
increase in current.
2. An indication of non-condensable gas in a refrigera-D
tion system is significantly:
a. Lower-than-normal suction pressures.
b. higher-than-normal suction pressures.
c. Lower-than-normal head pressures.
d. higher-than-normal head pressures.
3. An automatic expansion valve controls refrigerant A
flow to an evaporator by maintaining a constant:
a. Suction pressure.
b. Pressure differential across the valve port.
c. Liquid line pressure.
d. Superheat.
4. What is the approximate compression ratio of a
com- B pressor operating at 35 psig suction
pressure and 135 psig discharge pressure?
, NATE INDUSTRY COMPETENCY EXAM COMMERCIAL
REFRIGERATION EXAM QUESTIONS WITH ALL CORRECT &
VERIFIED ANSWERS
a. 1:03.
b. 3:01.
c. 1:04.
d. 4:01.
5.
The BTUs rejected at the condenser are always
greater D
than the heat absorbed in the evaporator because:
a. The condenser is mounted outside with
restricted airflow.
b. Of the high temperature of the discharge vapor
and length of the discharge line.
c. Of the inefficiency of the condenser and
pressure drop in the discharge line.
d. Of the heat of compression in the compressor.
6. A unit cooler is inspected and found to be
completely A iced up. The heaters and defrost
timer are found to be working properly. A
technician should:
a. Adjust the defrost termination switch to
a higher temperature setting.
b. Adjust the thermostatic expansion valve to a
higher superheat setting.
c.Clear all of the ice from the coil and find out
why the coil is frosted.
d. Increase the frequency of the defrost cycle.
7. what is the correct gauge pressure corresponding to
A
an absolute pressure of 24.7 psia at sea level?
,NATE INDUSTRY COMPETENCY EXAM COMMERCIAL
REFRIGERATION EXAM QUESTIONS WITH ALL CORRECT &
VERIFIED ANSWERS
a. 10 psig.
b. 12.6 psig.
, NATE INDUSTRY COMPETENCY EXAM COMMERCIAL
REFRIGERATION EXAM QUESTIONS WITH ALL CORRECT &
VERIFIED ANSWERS
c. 39.4 psig.
d. 39.7 psig.
8. For a lineup of medium temperature case, an
evap-
B orator temperature 0f 23°F is needed. The
following conditions exist:
· The suction line pressure drop is equivalent
to ap- proximately 2°F.
· The liquid line pressure drop is equivalent to
1°F. The compressor capacity should be
selected based on a saturated suction
temperature of:
a. 20°F.
b. 21°F.
c. 23°F.
d. 25°F.
9. What is true of systems with multiple evaporators at
A
different temperatures?
a. It is required to install evaporator pressure
regula- tor(s).
b. The compressor discharge pressure will be a
func- tion of the coldest space.
c. It is required to install a head pressure
control valve.
d. It is required to install a crankcase pressure
regula- tor.
REFRIGERATION EXAM QUESTIONS WITH ALL CORRECT &
VERIFIED ANSWERS
1. With the condensing pressure and compressor
speed D remaining constant, a decrease in
suction pressure will cause a(n):
a. Decrease in compressor capacity and
decrease in current.
b. Increase in compressor capacity and
decrease in current.
c. Increase in compressor capacity and
increase in current.
d. Decrease in compressor capacity and
increase in current.
2. An indication of non-condensable gas in a refrigera-D
tion system is significantly:
a. Lower-than-normal suction pressures.
b. higher-than-normal suction pressures.
c. Lower-than-normal head pressures.
d. higher-than-normal head pressures.
3. An automatic expansion valve controls refrigerant A
flow to an evaporator by maintaining a constant:
a. Suction pressure.
b. Pressure differential across the valve port.
c. Liquid line pressure.
d. Superheat.
4. What is the approximate compression ratio of a
com- B pressor operating at 35 psig suction
pressure and 135 psig discharge pressure?
, NATE INDUSTRY COMPETENCY EXAM COMMERCIAL
REFRIGERATION EXAM QUESTIONS WITH ALL CORRECT &
VERIFIED ANSWERS
a. 1:03.
b. 3:01.
c. 1:04.
d. 4:01.
5.
The BTUs rejected at the condenser are always
greater D
than the heat absorbed in the evaporator because:
a. The condenser is mounted outside with
restricted airflow.
b. Of the high temperature of the discharge vapor
and length of the discharge line.
c. Of the inefficiency of the condenser and
pressure drop in the discharge line.
d. Of the heat of compression in the compressor.
6. A unit cooler is inspected and found to be
completely A iced up. The heaters and defrost
timer are found to be working properly. A
technician should:
a. Adjust the defrost termination switch to
a higher temperature setting.
b. Adjust the thermostatic expansion valve to a
higher superheat setting.
c.Clear all of the ice from the coil and find out
why the coil is frosted.
d. Increase the frequency of the defrost cycle.
7. what is the correct gauge pressure corresponding to
A
an absolute pressure of 24.7 psia at sea level?
,NATE INDUSTRY COMPETENCY EXAM COMMERCIAL
REFRIGERATION EXAM QUESTIONS WITH ALL CORRECT &
VERIFIED ANSWERS
a. 10 psig.
b. 12.6 psig.
, NATE INDUSTRY COMPETENCY EXAM COMMERCIAL
REFRIGERATION EXAM QUESTIONS WITH ALL CORRECT &
VERIFIED ANSWERS
c. 39.4 psig.
d. 39.7 psig.
8. For a lineup of medium temperature case, an
evap-
B orator temperature 0f 23°F is needed. The
following conditions exist:
· The suction line pressure drop is equivalent
to ap- proximately 2°F.
· The liquid line pressure drop is equivalent to
1°F. The compressor capacity should be
selected based on a saturated suction
temperature of:
a. 20°F.
b. 21°F.
c. 23°F.
d. 25°F.
9. What is true of systems with multiple evaporators at
A
different temperatures?
a. It is required to install evaporator pressure
regula- tor(s).
b. The compressor discharge pressure will be a
func- tion of the coldest space.
c. It is required to install a head pressure
control valve.
d. It is required to install a crankcase pressure
regula- tor.
