Carrier 69NT40-561-300, Operation And Service Manual

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4–39 T-365
4.11 CONTROLLER ALARM INDICATIONS
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AL03 LOSS OF SUPERHEAT CONTROL
Cause: Superheat has remained below 1.66°C (3°F) degrees for five minutes continuously while compres-
sor running. Compressor drawing more than 2.0 amps, compressor pressure ratio is greater than
1.8, and Electronic Expansion Valve (EEV) is at 0% open.
Component Electronic Expansion Valve (EEV)
Troubleshooting Check the operation of the EEV using Cd41.
Corrective Action Replace EEV if defective.
Component Evaporator Temperature Sensor(s) ETS & ETS1.
Troubleshooting Verify accuracy of temperature sensors, refer to Sensor Checkout
Procedure
Section 7.25.1 .
Corrective Action Replace ETS or ETS1 if defective.
Component Evaporator Fans
Troubleshooting Confirm fans operating properly
Corrective Action Replace fan(s) if defective, refer to EVAPORATOR FAN MOTOR
ASSEMBLY
Section 7.14.1 .
AL05 MANUAL DEFROST SWITCH FAILURE
Cause: Controller has detected continuous Manual Defrost Switch activity for five minutes or more.
Component Keypad Power cycle the unit.
Troubleshooting Resetting the unit may correct problem, monitor the unit.
Corrective Action If the alarm reappears after 5 minutes replace the keypad.
AL06 KEYPAD OR KEYPAD HARNESS FAIL
Cause: Controller has detected one of the keypad keys is continuously activity.
Component Keypad or Harness
Troubleshooting Power cycle the unit. Resetting the unit may correct problem, monitor
the unit.
Corrective Action If the alarm reappears replace the keypad and harness.
AL07 FRESH AIR VENT OPEN
Cause: The VPS is reading greater than 0 CMH while unit is in frozen mode or XtendFRESH active.
Component Vent Position Sensor (VPS)
Troubleshooting Manually reposition vent and confirm using Cd45. Refer to VENT PO-
SITION SENSOR SERVICE
Section 7.26 .
Corrective Action If unable to obtain zero reading, replace defective VPS.