Carrier 69NT40--541--200 TO 299 Operation And Service page 45

Primary Supply Tem-
AL54 perature Sensor
Failure (STS)
Primary Return Tem-
AL56 perature Sensor
Failure (RTS)
Ambient Tempera-
AL57
ture Sensor Failure
Compressor High
AL58
Pressure Safety
Heat Termination
AL59
Thermostat
Defrost Temperature
AL60
Sensor Failure
AL61 Heaters Failure
Compressor Circuit
AL62
Failure
AL63 Current Over Limit
Discharge Tempera-
AL64
ture Over Limit
Discharge Pressure
AL65
Transducer Failure
Table 3-6 Controller Alarm Indications (Sheet 2 of 3)
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 sen-
sor 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 acti-
vated 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 valid 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 remain active until the pres-
sure switch resets, at which time the compressor 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.
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 7_C (45_F), 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 tempera-
ture sensor. The defrost mode will be terminated after one hour by the Controller.
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.
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 mini-
mum 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.
Alarm 63 is triggered by the current limiting system. If the compressor is ON and
current limiting procedures cannot maintain a current level below the user se-
lected limit, the current limit alarm is activated.This alarm is a display alarm and
is inactivated by power cycling the unit, changing the current limit via the code
select Cd32, or if the suction modulation valve (SMV) is open beyond the control-
ler desired point.
Alarm 64 is triggered if the discharge temperature sensed is greater than 135_C
(275_F) for three continuous minutes, if it exceeds 149_C (300_F), or if the sen-
sor is out of range. This is a display alarm and has no associated failure action.
Alarm 65 is triggered by a compressor discharge transducer reading outside the
valid range of 73.20 cm Hg (30 in Hg) to 32.34 Kg/cm
play alarm and has no associated failure action.
NOTE
NOTE
3-19
2
(460 psig). This is a dis-
T-317