478
Modern Refrigeration and Air Conditioning
4. Why should an extension cord not be used to
connect a refrigerator to an outlet?
A. An extension cord cannot provide an
adequate ground.
B. An extension cord may cause an
unacceptable voltage drop.
C. An extension cord does not allow overload
protection of the circuit.
D. All of the above.
5. How much air space must be provided around
all sides of a refrigerator or freezer with a hot-
wall condenser?
A. 2″ (51 mm)
B. 4″ (102 mm)
C. 6″ (154 mm)
D. 12″ (307 mm)
6. If a refrigerator will not start and the interior
light does not come on when the door is
opened, which of the following is the most
likely cause of the problem?
A. A problem in the motor control circuits.
B. A mechanical problem in compressor.
C. A problem in the electrical supply circuit.
D. Excessive head pressure.
7. Which of the following can cause a buildup
of frost on an evaporator?
A. A leaky door gasket.
B. A clogged metering device.
C. A clogged filter-drier.
D. A dirty condenser.
8. Which of the following would prevent a newly
installed ice maker from operating properly?
A. The signal arm is in the down position.
B. The temperature of the ice mold is held at
20°F (–7°C).
C. The thermostat is wired in series with the
mold heater.
D. All of the above.
9. Which of the following affects a refrigerator or
freezer cycling time?
A. Amount of storage space inside the cabinet.
B. Temperature outside the cabinet.
C. Compressor condition.
D. All of the above.
10. If a refrigerator-freezer operates, but the cabinet
is too warm, which of the following is the most
likely cause?
A. A problem with the compressor motor.
B. A problem with the supply circuit.
C. The evaporator is iced over.
D. A problem with the mullion heater.
11. Ground wires are always _____.
A. white
B. black
C. red
D. green
12. Which of the following is a test a technician can
perform to see if the thermostat is the cause of
a no-start condition?
A. The technician turns the thermostat to its
highest setting. If the system does not start,
the problem is in the thermostat.
B. The technician turns the thermostat to its
lowest setting. If the system does not start,
the problem is in the thermostat.
C. The technician bypasses the thermostat.
If the system starts, the problem is in the
thermostat.
D. The technician bypasses the thermostat.
If the system does not start, the problem is
in the thermostat.
13. Which of the following condition can result
in frost on the suction line?
A. An insufficient refrigerant charge.
B. An overcharge of refrigerant.
C. A partially clogged metering device.
D. All of the above.
14. A _____ is a small length of sealed tubing that
extends out through the compressor housing
and is used to service the system.
A. service tube
B. process tube
C. valve adapter
D. service stub
15. A system has symptoms corresponding to a
restriction in the metering device, but begins
working properly again when heat is applied
to the metering device. Which of the following
is the most likely cause?
A. Wax buildup clogging the metering device.
B. Shortage of refrigerant.
C. Leaking compressor valves.
D. Moisture in the system.