Carrier 69NT40-541-505, Operation And Service Manual

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4–31 T-368
4.11 CONTROLLER ALARM INDICATIONS
AL05 MANUAL DEFROST SWITCH FAILURE
Cause: Controller has detected continuous Manual Defrost Switch activity for five minutes or more.
Component Keypad
Troubleshooting
Power cycle the unit.
Corrective Action
Resetting the unit may correct problem, monitor the unit.
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.
Corrective Action
Resetting the unit may correct problem, monitor the unit.
If the alarm reappears replace the keypad and harness.
AL07 FRESH AIR VENT OPEN WITH FROZEN SET POINT
Cause: The VPS is reading greater than 0 CMH while unit is in frozen mode.
Component Vent Position Sensor (VPS)
Troubleshooting Manually reposition vent and confirm using Cd45. Refer to VENT POSI-
TION SENSOR SERVICE
Section 7.22 .
Corrective Action If unable to obtain zero reading, replace defective VPS.
AL10 CO
2
SENSOR FAILURE
Cause: Alarm 10 is triggered when the CO
2
sensor voltage is operating outside of the 0.9 v to 4.7 v range,
or if the sensor is out of range.
Component This is a display alarm and has no associated failure action.
Troubleshooting Refer to eAutoFresh manual.
Corrective Action
The alarm is triggered off when voltage is within operating range.
AL11 EVAPORATOR FAN 1 IP
Cause: Alarm 11 is triggered when configured for single evap operation and MC6 sensed high.
Component Evaporator Fan 1
Troubleshooting The unit will suspend probe check diagnostic logic and disable the probe
check portion of defrost cycle.
Corrective Action AL11 is triggered off when MC6 sensed low.
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