Carrier 48LC Series Controls, Start-Up, Operation And Troubleshooting page 30

shorted or open thermistor caused by a wiring error, or a loose
connection.
Alert A102 – FST OPEN SENSOR
This alert occurs when the fan supply temperature sensor reads as
an open circuit. This alert resets automatically. The cause of the
alert is usually a faulty thermistor or an open thermistor caused by
a wiring error, or a loose connection.
Alert A103 – FST SHORTED SENSOR
This alert occurs when the fan supply temperature sensor reads as a
short circuit. This alert resets automatically. The cause of the alert is
usually a faulty thermistor or a shorted thermistor caused by a
wiring error, or a loose connection.
Alert A104 – OAT SENSOR RANGE
This alert occurs when the outdoor air temperature is outside the
range –40_F to 245_F (–40_C to 116_C). All ambient temperature
lockout limits for cooling and heating are ignored. All cooling
control logic will assume OAT is high. For economizer equipped
units, the economizer will not operate to provide cooling. The
economizer will still operate for ventilation. The control will use
normal operation for outdoor fan control. For units with CCH
crankcase heat relay control, the crankcase heat relay will be turned
on if any compressor is off. This alert resets automatically. The
cause of the alert is usually a faulty thermistor, a shorted or open
thermistor caused by a wiring error, or a loose connection.
Alert A105 – OAT OPEN SENSOR
See Alert A104
Alert A106 – OAT SHORTED SENSOR
See Alert A104
Alert A107 - - RAT SENSOR RANGE
This alert occurs when the return air temperature is outside the
range –40_F to 245_F (–40_C to 116_C). Differential dry bulb
crossover control can not occur. Free cooling can only be
controlled by the OAT and enthalpy switch. The economizer
mechanically disconnected alert will not be diagnosed. This alert
resets automatically. The cause of the alert is usually a faulty
thermistor, a shorted or open thermistor caused by a wiring error,
or a loose connection.
Alert A108 – RAT OPEN SENSOR
See Alert A107
Alert A109 – RAT SHORTED SENSOR
See Alert A107
Alert A110 – SPT SENSOR RANGE
This alert occurs when the temperature is outside the range –40_F
to 245_F (–40_C to 116_C). Cooling and heating will not operate.
For economizer equipped units, the economizer will still operate
for ventilation. This alert resets automatically. The cause of the
alert is usually a faulty thermistor in the T- -55, T- -56, or T- -58
device, a shorted or open thermistor caused by a wiring error, or a
loose connection.
Alert A111 – SPT OPEN SENSOR
See Alert A110
Alert A112 – SPT SHORTED SENSOR
See Alert A110
Alert A130 – CIR.A SSP SENSOR RANGE
This alert occurs when the pressure is outside the range - -6.7 to 420
psig. A circuit cannot run when this alert is active. The cause of the
alert is usually a faulty transducer, faulty 5- -v power supply, or a
loose connection. Use the transducer voltage drop table to
determine where the error is introduced.
Alert A131 – CIR.A SSP OPEN SENSOR
See Alert A130
Alert A132 – CIR.A SSP SHORT SENSOR
See Alert A130
Alert A133 – CIR.A SDP SENSOR RANGE
This alert occurs when the pressure is outside the range 14.5 to 667
psig. A circuit cannot run when this alert is active. The cause of the
alert is usually a faulty transducer, faulty 5- -v power supply, or a
loose connection. Use the transducer voltage drop table to
determine where the error is introduced.
Alert A134 – CIR.A SDP OPEN SENSOR
See Alert A130
Alert A135 – CIR.A SDP SHORT SENSOR
See Alert A130
Alert 150 - - OACFM OPEN SENSOR
This alert occurs when the Outdoor Air CFM sensor input is 0 mA
and the sensor is configured and installed. Check sensor and
wiring. This alert clears automatically.
Alert 151 - - OACFM SHORTED SENSOR
This alert occurs when the Outdoor Air CFM sensor input shorted
and the sensor is configured as installed. Check sensor and wiring.
This alert clears automatically.
Alert A160 – OARH OPEN SENSOR
This alert occurs when the Outdoor Air Relative Humidity sensor
input is 0 mA and the sensor is configured as installed. Outside Air
Enthalpy cannot be calculated therefore no enthalpy crossover can
be used and only dry bulb will be used in determining free cooling.
Check sensor and wiring. This alert clears automatically.
Alert A161 – OARH SHORTED SENSOR
This alert occurs when the Outdoor Air Relative Humidity sensor
input shorted and the sensor is configured as installed. Outside Air
Enthalpy cannot be calculated therefore no enthalpy crossover can
be used and only dry bulb will be used in determining free cooling.
Check sensor and wiring. This alert clears automatically.
Alert A162 – RARH OPEN SENSOR
This alert occurs when the Return Air Relative Humidity sensor
input is 0 mA and the sensor is configured as installed. Return Air
Enthalpy cannot be calculated therefore no differential enthalpy
crossover can be used. Dry bulb and single enthalpy will be used in
determining free cooling. Check sensor and wiring. This alert
clears automatically.
Alert A163 – RARH SHORTED SENSOR
This alert occurs when the Return Air Relative Humidity sensor
input shorted and the sensor is configured as installed. Return Air
Enthalpy cannot be calculated therefore no differential enthalpy
crossover can be used. Dry bulb and single enthalpy will be used in
determining free cooling. Check sensor and wiring. This alert
clears automatically.
Alert A164 - - IAQ OPEN SENSOR
This alert occurs when the IAQ input is 0 mA and the sensor is
configured as installed. IAQ operation will be disabled. Check
sensor and wiring. This alert clears automatically.
Alert A165 - - IAQ SHORTED SENSOR
This alert occurs when the IAQ input is shorted and the sensor is
configured as installed. IAQ operation will be disabled. Check
sensor and wiring. This alert clears automatically.
Alert A166 - - OAQ OPEN SENSOR
This alert occurs when the OAQ input is 0 mA and the sensor is
configured as installed. OAQ operation will be disabled. Check
sensor and wiring. This alert clears automatically.
Alert A167 - - OAQ SHORTED SENSOR
This alert occurs when the OAQ input is shorted and the sensor is
configured as installed. OAQ operation will be disabled. Check
sensor and wiring. This alert clears automatically.
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