Carrier 69NT40-541-300, Operation And Service

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T-318 3 − 33
Table 3-6 Controller Alarm Indications (Sheet 4 of 6)
Alarm Code Cause Components Troubleshooting Corrective Actions
AL57
Ambient
Sensor
(AMBS)
Invalid Ambient
Temperature Sensor
(AMBS) reading.
Ambient
Temperature
Sensor (AMBS)
Test the AMBS, refer to
TEMPERATURE
SENSOR Service Section
6.24.
Replace AMBS if
defective, refer to
TEMPERATURE
SENSOR Service
Section 6.24.
AL58
Compressor
High Pressure
Safety (HPS)
High pressure safety
switch remains open
for at least one minute.
High Pressure
Switch (HPS)
Test the HPS; refer to High
Pressure Switch, Section
6.9.
Replace HPS if
defective, refer to High
Pressure Switch,
Section 6.9.
Refrigeration
System
Check unit for air flow
restrictions.
Clean or remove any
debris from coils.
AL59
Heater
Termination
Thermostat
(HTT)
Heat Termination
Thermostat (HTT) is
open.
Alarm 59 is trig-
gered by the open-
ing of the Heat Ter-
mination Thermo-
stat (HTT) and will
result in the disab-
ling of the heater.
Check for 24 volts at test
point TP10, if no voltage at
TP10 after unit has
reached set point HTT is
open.
Replace HTT if
defective.
AL60
Defrost
Temperature
Sensor (DTS)
Failure of the Defrost
Temperature Sensor
(DTS) to open.
Defrost
Temperature
Sensor (DTS)
Test the DTS; refer to
Sensor Checkout Proced-
ure Section 6.24.1.
Replace the DTS if
defective, refer to
Sensor Replacement
Section 6.24.2.
AL61
Heater
Current Draw
Fault
Improper current draw
during heat or defrost
mode.
Heater(s) While in heat or defrost
mode, check for proper
current draw at heater
contactors, refer to
ELECTRICAL DATA
Section 2.3.
Replace heater(s) if
defective, refer to
Section 6.15.2
Evaporator Heater
Removal and
Replacement.
Contactor Check voltage at heater
contactor on the heater
side. If no voltage present:
Replace heater contact-
or if defective.
AL63
Current Limit
Unit operating above
current limit.
Refrigeration
System
Check unit for air flow
restrictions.
Clean or remove any
debris from coils.
Check unit for proper
operation.
Repair as needed.
Power supply Confirm supply voltage/fre-
quency is within specifica-
tion and balanced accord-
ing to ELECTRICAL DATA
Section 2.3.
Correct power supply.
Current limit set
too low.
Check current limit setting
Code Cd32.
The current limit can be
raised (maximum of 23
amps) using Cd32.
AL64
Discharge
Temperature
Sensor
(CPDS)
Discharge
Temperature sensor
out of range.
Discharge
temperature
sensor (CPDS).
Test the CPDS; refer to
TEMPERATURE
SENSOR Service Section
6.24..
Replace the CPDS if
defective, refer to
TEMPERATURE
SENSOR Service Sec-
tion 6.24.
AL65
Discharge
Pressure
Transducer
(DPT)
Compressor
Discharge Transducer
is out of range.
Compressor
Discharge
Transducer (DPT)
Confirm accurate DPT
pressure readings, refer to
MANIFOLD GAUGE SET
Section 6.2.
Replace DPT if
defective.