Carrier 48/50PD05 manual ComfortLink Alarm Codes

Table 8 — ComfortLink™ Alarm Codes

ALARM
OR	DESCRIPTION	ACTION TAKEN BY	RESET	PROBABLE CAUSE
ALERT		CONTROL	METHOD
NUMBER
	Digital Compressor Control Board Alarm	No action	Automatic	See the DSC’s LEDs for troubleshooting
	Compressor A1 Safety Trip	Add Strike for Circuit A	Automatic	Current Sensing turned on (CS.A1 = Enable) and
				should be off
	Service Test --- Compressor A1 Safety Trip	Add Strike for Circuit A	Automatic	Current Sensing turned on (CS.A1 = Enable) and
T051				should be off
	Compressor A1 Current Detected After	Turn off all	Automatic	Current Sensing turned on (CS.A1 = Enable) and
	Turnoff	compressors		should be off
	Service Test --- Compressor A1 Current	Turn off all	Automatic	Current Sensing turned on (CS.A1 = Enable) and
	Detected After Turnoff	compressors		should be off
T064	Circuit A Saturated Condensing Temp	Use OAT to control	Automatic	Faulty, shorted, or open thermistor caused by wiring
	Thermistor Failure	Outdoor fans		error or loose connection.
T066	Circuit A Saturated Suction Temperature	No Cooling	Automatic	Suction transducers internally forced inactive
	Thermistor Failure
T073	Outdoor Air Temperature Thermistor Failure	No cooling with	Automatic	Faulty, shorted, or open thermistor caused by wiring
		economizer		error or loose connection.
T074	Space Temperature Thermistor Failure	No heating or cooling	Automatic	Faulty, shorted, or open thermistor caused by wiring
				error or loose connection.
T075	Supply Air Temperature Thermistor Failure	No cooling mode	Automatic	Faulty, shorted, or open thermistor caused by wiring
				error or loose connection.
T076	Return Air Thermistor Failure	No differential DB	Automatic	Faulty, shorted, or open thermistor caused by wiring
		crossover		error or loose connection.
T077	Space Relative Humidity Sensor Failure	If RH.S = Yes, then no	Automatic	Faulty, shorted, or open sensor caused by wiring
		indoor humidity control		error or loose connection.
T092	Circuit A Suction Pressure Transducer	Shutdown Circuit A	Manual	Faulty transducer, faulty 5---V power supply, or loose
	Failure			connection
T102		If CS.A1 = Enable,		Current Sensing turned on (CS.A1 = Enable) and
	Compressor A1 Current Sensor Failure	then no T051 current	Automatic
				should be off
		alarm
T110	Circuit A Loss of Charge	Shutdown Circuit A	Manual	Low refrigerant or faulty suction pressure transducer
	Service Test --- Circuit A Loss of Charge	Shutdown Circuit A	Manual	Low refrigerant or faulty suction pressure transducer
				An overcharged system, high outdoor ambient
	Circuit A High Discharge Pressure	Shutdown Circuit A	Automatic	temperature coupled with dirty outdoor coil, plugged
T126				filter drier, or a faulty high---pressure switch.
	Service Test --- Circuit A High Discharge			An overcharged system, high outdoor ambient
		Shutdown Circuit A	Automatic	temperature coupled with dirty outdoor coil, plugged
	Pressure
				filter drier, or a faulty high---pressure switch.
				Low refrigerant charge, dirty filters, evaporator fan
				turning backwards, loose or broken fan belt, plugged
	Circuit A Low Refrigerant Pressure	Add Strike for Circuit A	Automatic	filter drier, faulty transducer, excessively cold return
				air, or stuck open economizer when the ambient
T133				temperature is low.
				Low refrigerant charge, dirty filters, evaporator fan
	Service Test --- Circuit A Low Refrigerant			turning backwards, loose or broken fan belt, plugged
		Add Strike for Circuit A	Automatic	filter drier, faulty transducer, excessively cold return
	Pressure
				air, or stuck open economizer when the ambient
				temperature is low.
T143	Circuit A Failure To Pressurize	Add Strike for Circuit A	Automatic	Wiring causing reverse rotation or faulty compressor
	Service Test --- Circuit A Failure To	Add Strike for Circuit A	Automatic	Wiring causing reverse rotation or faulty compressor
	Pressurize
T153	Real Timeclock Hardware Failure	No time and date	Automatic	No time/date configured, software failure, or MBB
		schedule operation		failure
A154	Serial EEPROM Hardware Failure	Unit Shutdown	Automatic	Software failure or MBB failure
T155	Serial EEPROM Storage Failure Error	Unit operation errors	Automatic	Software failure or MBB failure
A156	Critical Serial EEPROM Storage Fail Error	Unit Shutdown	Automatic	Software failure or MBB failure
A157	A/D Hardware Failure	Unit Shutdown	Automatic	Software failure or MBB failure
	Circuit A Down Due to Failure	Shutdown Circuit A	Manual	Circuit has 3 strikes or has been locked out by
A163				another alarm
	Service Test --- Circuit A Down Due to	Shutdown Circuit A	Manual	Circuit has 1 strike or has been locked out by another
	Failure			alarm

* See Legend on next page

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