WorksheetsDigital Thermometer Troubleshooting Quiz
Total questions: 59
Worksheet time: 30mins
What is the correct voltage and polarity that must be applied to the terminals during the checkout procedure?
0-5V, positive on the terminal
0-5V, negative on the terminal
0-15V, positive on the terminal
0-15V, negative on the terminal
What should be done if the problem with the digital thermometer is still uncorrected after checking the connections?
Replace the sensor
Replace the display head
Replace the entire unit
Replace the battery
What is the resistance value at 32°F (0°C) for the digital thermometer?
3024 ohms
3365 ohms
3948 ohms
3014 ohms
What is the accuracy of the digital thermometer at 32°F (0°C)?
± 1°F (± 0.6°C)
± 2°F (± 1.1°C)
± 3°F (± 1.7°C)
± 4°F (± 2.2°C)
What is the purpose of the small recalibration screw on the digital thermometer?
To adjust the display brightness
To adjust the temperature reading
To adjust the power supply
To adjust the sensor position
What is the first step in the thermostat checkout procedure?
Set the thermostat dial to 6°F (3.3°C) or more below the unit's room temperature.
Slowly rotate the dial CCW until the dial setting reaches approximately 3°F below the unit's room temperature.
Set the unit to Mode 1.
Verify that the thermostat switch sequence is correct.
What should be done after setting the thermostat dial to 6°F (3.3°C) or more below the unit's room temperature?
Set the unit to Mode 1.
Slowly rotate the dial CCW until the dial setting reaches approximately 3°F below the unit's room temperature.
Verify that the thermostat switch sequence is correct.
Tighten the screws with the indicator mark.
What is the correct procedure for the thermostat calibration?
Prepare an ice water bath and immerse the thermostat sensing bulb.
Place the sensor bulb in the ice water bath.
Slowly rotate the dial CCW until the dial setting reaches approximately 3°F below the unit's room temperature.
Set the thermostat dial to 6°F (3.3°C) or more below the unit's room temperature.
What is the correct action to take after preparing an ice water bath for thermostat calibration?
Set the thermostat dial to 6°F (3.3°C) or more below the unit's room temperature.
Slowly rotate the dial CCW until the dial setting reaches approximately 3°F below the unit's room temperature.
Remove the clamps in the evaporator.
Place the sensor bulb in the ice water bath.
What should the sensor resistance be at 32°F (0°C)?
3000 ohms
3260 ohms
3500 ohms
3948 ohms
What is the first step in the thermostat module test procedure?
Connect the sensor to the module
Turn the ON/OFF switch to OFF
Check the voltage between terminals 1 and 4
Place the sensor bulb in ice water
What should you do if the sensor is defective?
Replace the sensor
Replace the thermostat module
Replace the heat relay
Replace the speed relay
At what temperature should the sensor resistance be approximately 3948 ohms?
32°F (0°C)
80°F (26.6°C)
14°F (-10°C)
50°F (10°C)
What should be done after connecting the sensor to the module?
Check the voltage between terminals 1 and 4
Place the sensor bulb in ice water
Turn the ON/OFF switch to ON
Connect the 12V battery
What is the correct position for the High Speed Heat Lockout jumper wire between terminals?
Between B and C
Between A and B
Between A and C
No jumper wire is needed
What should be the voltage between terminals 10 and CH during the CYCLE-SENTRY® check?
0 volts
12 volts
24 volts
32 volts
What should be the voltage between terminals 14 and CH during the CYCLE-SENTRY® check?
0 volts
12 volts
24 volts
32 volts
What should be the voltage between terminals 29 and 32 F during the CYCLE-SENTRY® check?
0 volts
12 volts
24 volts
32 volts
What is the normal temperature range for the thermostat in the High Speed Heat Lockout position?
10°F (-12°C)
15°F (-9.4°C)
20°F (-6.7°C)
25°F (-3.9°C)
What should be done if the defrost cycle does not complete properly?
Ignore the issue
Check the defrost timer during scheduled maintenance
Replace the entire system
Increase the temperature setting
What should be the voltage between terminals 14 and CH during the defrost cycle?
0 volts
12 volts
24 volts
32 volts
What should be the voltage between terminals 10 and CH during the defrost cycle?
0 volts
12 volts
24 volts
32 volts
What should be the voltage between terminals 29 and 32 F during the defrost cycle?
0 volts
12 volts
24 volts
32 volts
What should be done if the defrost cycle does not complete properly?
Ignore the issue
Check the defrost timer during scheduled maintenance
Replace the entire system
Increase the temperature setting
What is the function of the Heat Lockout Switch?
To control the fan speed
To lock out the heat during certain conditions
To regulate the voltage
To monitor the temperature
What should be the voltage between terminals 10 and CH during the CYCLE-SENTRY® check?
0 volts
12 volts
24 volts
32 volts
What should be the voltage between terminals 14 and CH during the CYCLE-SENTRY® check?
0 volts
12 volts
24 volts
32 volts
What should be the voltage between terminals 29 and 32 F during the CYCLE-SENTRY® check?
0 volts
12 volts
24 volts
32 volts
What should be checked to ensure the evaporator temperature is correct?
The defrost termination
The defrost air switch
The No. 8 wire
The No. 12 wire
What should be done if the unit fails to defrost after checking the defrost termination?
Replace the No. 8 wire
Place a jumper wire from the No. 12 wire to the ground
Check the defrost air switch
Check the evaporator temperature
What is the first step in the defrost cycle checkout procedure?
Check the defrost air switch
Place a jumper wire from the No. 8 wire to the ground
Check the evaporator temperature
Check the No. 26 wire
What should be done if the defrost indicator light does not come on after placing a jumper wire from the No. 8 wire to the ground?
Check the No. 12 wire
Check the defrost air switch
Check the evaporator temperature
Check the No. 26 wire
What should be done if the unit does not shift into defrost after checking the No. 26 wire?
Replace the No. 8 wire
Replace the No. 12 wire
Check the defrost air switch
Check the evaporator temperature
What should be checked if the unit fails to complete the defrost cycle?
The defrost relay
The No. 11A wire
The evaporator coil
The compressor
What is the first step if the unit does not terminate defrost?
Check the defrost relay
Check the No. 11A wire
Check the evaporator coil
Check the compressor
What should be done if the defrost relay is powered but the unit fails to terminate defrost?
Replace the defrost relay
Check the No. 11A wire
Check the evaporator coil
Check the compressor
What does the defrost timer do?
It initiates and terminates the defrost cycle
It controls the compressor
It regulates the evaporator coil
It monitors the refrigerant level
What should be checked if the unit fails to terminate defrost and the defrost relay is not powered?
The No. 11A wire
The defrost timer
The evaporator coil
The compressor
What is the first step in the Defrost Timer Test procedure?
Connect the defrost termination thermostat.
Depress the defrost termination switch.
Connect a jumper from the timer test point to ground.
Remove the defrost timer.
How long should the defrost cycle last according to the Defrost Timer Test?
1.9 minutes
12 minutes
8 hours
4 hours
What should be done if the defrost timer fails and replacement is not available?
Remove the defrost timer.
Connect a jumper from the timer test point to ground.
Bypass the timer using a jumper wire.
Depress the defrost termination switch.
What is the purpose of the Defrost Timer Bypass procedure?
To test the defrost timer.
To replace the defrost timer.
To allow the air switch to provide defrosting.
To connect the defrost termination thermostat.
What should be done if the defrost cycle does not repeat until the 12 circuit opens?
Replace the defrost timer.
Depress the defrost termination switch.
Connect a jumper from the timer test point to ground.
Remove the defrost timer.
What is the first step in testing the air switch?
Disconnect the power to the unit.
Remove plastic sensing tubing from both sides of the defrost air switch.
Connect the test equipment.
Cool the defrost termination switch below 37°F.
What tool is used to test the continuity of the air switch?
Tool No. 204-442
Tool No. 204-494
Tool No. 204-444
Tool No. 204-495
What should be done before performing the test on the defrost air switch?
Allow adequate time for the temperature to stabilize.
Ensure the air switch is in the correct position.
Check the clear coil.
Adjust the screw.
What does the defrost relay control?
The temperature of the unit.
The operation of the unit on the defrost cycle.
The power supply to the unit.
The airflow across the coil.
What happens when the defrost termination switch is activated?
The defrost cycle is initiated.
The defrost relay is deactivated.
The pilot solenoid and the defrost solenoid are de-energized.
The air switch is reset.
What is the function of the pilot solenoid?
It controls the temperature of the unit.
It controls the operation of the defrost cycle.
It controls the three-way valve in the refrigeration system.
It controls the airflow across the coil.
What indicates a restricted airflow in the defrost air switch?
A pressure difference between the two sides of the coil.
A temperature difference between the two sides of the coil.
A voltage difference between the two sides of the coil.
A current difference between the two sides of the coil.
What is the primary function of the FuelSaver module (FSM)?
To control the high-speed fan
To control the low-speed fan
To control the unloader relay
To control the defrost operation
What should be done if the switch is out of calibration?
Turn the adjustment screw counterclockwise
Turn the adjustment screw clockwise
Replace the switch
Increase the pressure setting
What is the recommended pressure setting for the FuelSaver module?
1.5 in. Hg (± 0.25 mm)
1.0 in. Hg (± 0.25 mm)
1.4 in. Hg (± 0.25 mm)
1.2 in. Hg (± 0.25 mm)
What is the purpose of the unloader relay (KF2)?
To control the high-speed fan
To control the low-speed fan
To control the defrost operation
To control the unloader
What should be done if too much frost accumulates during defrost?
Increase the pressure setting
Decrease the pressure setting
Turn the adjustment screw counterclockwise
Turn the adjustment screw clockwise
What should be done first when performing a bench test for the FSM module?
Connect a test light labeled "A" between terminals 7 and 8.
Attach a test lead to the CH terminal and the negative terminal of the power source.
Remove the failsaver module (FSM) from the unit and bench test it.
Connect a second test light labeled "B" between terminals 7 and 8.
What should happen when the test lead is attached to the CH terminal and the negative terminal of the power source?
The test light labeled "A" should come on.
The test light labeled "B" should come on.
Both test lights should come on.
The test light labeled "A" should go off.
How long should the power source be connected to the FSM module during the bench test?
Approximately one minute
Approximately three seconds
Approximately ten seconds
Approximately five seconds
What should happen to the test lights after the power source is connected for approximately three seconds?
Both test lights should go off.
The test light labeled "A" should go off, and the test light labeled "B" should come on.
Both test lights should come on.
The test light labeled "B" should go off, and the test light labeled "A" should come on.
