Operating instructions

TM 11574A-OI
2-32
Table 2-7 Controller Alarm Indications - Continued
Code
No.
TITLE DESCRIPTION
AL53 Battery Pack Failure
Alarm 53 is caused by the battery pack charge being too low to provide sufficient
power for battery-backed recording. Renew replaceable batteries. If this alarm
occurs on start up, allow a unit fitted with rechargeable batteries to operate for up to
24 hours to charge rechargeable batteries sufficiently to deactivate the alarm
AL54
Primary Supply
Temperature
Sensor Failure
(STS)
Alarm 54 is activated by an invalid primary supply temperature sensor reading that
is sensed outside the range of -58 F to +158 F (-50 to +70 C) 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.
NOTE
The P5 Pre-Trip test must be run to inactivate the alarm
AL56
Primary Return
Temperature
Sensor Failure
(RTS)
Alarm 56 is activated by an invalid primary return temperature sensor reading that
is outside the range of -58 F to +158 F (-50 to +70 C). 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.
NOTE
The P5 Pre-Trip test must be run to inactivate the alarm
AL57
Ambient
Temperature
Sensor Failure
Alarm 57 is triggered by an ambient temperature reading outside the valid range
from -58 F to +158 F (-50 to +70 C).
AL58
Compressor High
Pressure Safety
Alarm 58 is triggered when the compressor high discharge pressure safety switch
remains open for at least one minute. This alarm will remain active until the
pressure switch resets, at which time the compressor will restart.
AL59
Heat Termination
Thermostat
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.
AL60
Defrost
Temperature
Sensor Failure
Alarm 60 is an indication of a probable failure of the defrost temperature sensor
(DTS). It is triggered by the opening of the heat termination thermostat (HTT) or
the failure of the DTS to go above set point within two hours of defrost initiation.
After one-half hour with a frozen range set point, or one-half hour of continuous
compressor run time, if the return air falls below 45 F (7 C), the Controller checks
to ensure the DTS reading has dropped to 10 C or below. If not, a DTS failure
alarm is given and the defrost mode is operated using the return temperature
sensor. The defrost mode will be terminated after one hour by the Controller.
AL61 Heaters Failure
Alarm 61 is triggered by detection of improper amperage resulting from heater
activation or deactivation. Each phase of the power source is checked for proper
amperage. This alarm is a display alarm with no resulting failure action, and will
be reset by a proper amp draw of the heater.
AL62
Compressor
Circuit Failure
Alarm 62 is triggered by improper current draw increase (or decrease) resulting
from compressor turn on (or off). The compressor is expected to draw a minimum
of 2 amps; failure to do so will activate the alarm. This is a display alarm with no
associated failure action and will be reset by a proper amp draw of the
compressor.