Carrier 69NT40-541-001 Operation And Service page 60

CODE # TITLE
AL51 Alarm List Failure
AL52 Alarm List Full
AL53 Battery Pack Failure
Primary Supply Temperature
AL54
Sensor Failure (STS)
Primary Return Temperature
AL56
Sensor Failure (RTS)
Ambient Temperature
AL57
Sensor Failure
Compressor High
AL58
Pressure Safety
AL59 Heat Termination Thermostat
T-316
Table 4–6 Controller Alarm Indications (Continued)
During start-up diagnostics, the EEPROM is examined to determine va-
lidity of its contents. This is done by testing the set point and the alarm
list. If the contents are invalid, Alarm 51 is activated. During control pro-
cessing, any operation involving alarm list activity that results in an error
will cause Alarm 51 to be activated. Alarm 51 is a "display only" alarm
and is not written into the alarm list. Pressing the ENTER key when
"CLEAr" is displayed will result in an attempt to clear the alarm list. If that
action is successful (all alarms are inactive), Alarm 51 will be reset.
Alarm 52 is activated whenever the alarm list is determined to be full; at
start-up or after recording an alarm in the list. Alarm 52 is displayed, but
is not recorded in the alarm list. This alarm can be reset by clearing the
alarm list. This can be done only if all alarms written in the list are inactive.
Alarm 53 is caused by the battery pack charge being too low to provide
sufficient power for battery-backed recording. Renew replaceable bat-
teries. If this alarm occurs on start up, allow a unit fitted with recharge-
able batteries to operate for up to 24 hours to charge rechargeable
batteries sufficiently to deactivate the alarm.
Alarm 54 is activated by an invalid primary supply temperature sensor
reading that is sensed outside the range of -50 to +70°C (-58°F to +158°F)
or if the probe check logic has determined there is a fault with this sensor.
If Alarm 54 is activated and the primary supply is the control sensor, the
secondary supply sensor will be used for control if the unit is so equipped.
If the unit does not have a secondary supply temperature sensor, and
AL54 is activated, the primary return sensor reading, minus 2°C will be
used for control.
The P5 Pre-Trip test must be run to inactivate the alarm
Alarm 56 is activated by an invalid primary return temperature sensor
reading that is outside the range of -50 to +70°C (-58°F to +158°F). If
Alarm 56 is activated and the primary return is the control sensor, the
secondary return sensor will be used for control if the unit is so
equipped. If the unit is not equipped with a secondary return temperature
sensor or it fails, the primary supply sensor will be used for control.
The P5 Pre-Trip test must be run to inactivate the alarm.
Alarm 57 is triggered by an ambient temperature reading outside the val-
id range from -50°C (-58°F) to +70°C (+158°F).
Alarm 58 is triggered when the compressor high discharge pressure
safety switch remains open for at least one minute. This alarm will re-
main active until the pres sure switch resets, at which time the compres-
sor will restart.
Alarm 59 is triggered by the opening of the heat termination thermostat
and will result in the disabling of the heater. This alarm will remain active
until the thermo stat resets.
DESCRIPTION
NOTE
NOTE
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