Carrier Air Conditioner Alarm Codes – 30GTN Service Manual and Troubleshooting

Table 29 — Alarm and Alert Codes

ALARM/	ALARM		WHY WAS THIS	ACTION TAKEN	RESET	PROBABLE
ALERT	OR	DESCRIPTION	ALARM	ACTION TAKEN	RESET	PROBABLE
ALERT	OR	DESCRIPTION	ALARM	BY CONTROL	METHOD	CAUSE
CODE	ALERT		GENERATED?	BY CONTROL	METHOD	CAUSE
CODE	ALERT		GENERATED?

T051	Alert	Circuit A, Compressor 1	Compressor feedback signal	Circuit A shut down.	Manual	High-pressure or loss-of-
		Failure	does not match relay state			charge switch open, faulty
						control relay or CPCS board,
						loss of condenser air, liquid
						valve closed, operation
						beyond capability.
T052	Alert	Circuit A, Compressor 2	Compressor feedback signal	Circuit A shut down. Circuit	Manual	High-pressure switch open,
		Failure	does not match relay state	restarted in 1 minute. Com-		faulty control relay or CPCS
				pressor A2 not used until		board, loss of condenser air,
				alarm is reset.		liquid valve closed, opera-
						tion beyond capability.
T053	Alert	Circuit A, Compressor 3	Compressor feedback signal	Circuit A shut down. Circuit	Manual	High-pressure switch open,
		Failure	does not match relay state	restarted in 1 minute. Com-		faulty control relay or CPCS
				pressor A3 not used until		board, loss of condenser air,
				alarm is reset.		liquid valve closed, opera-
						tion beyond capability.
T054	Alert	Circuit A, Compressor 4	Compressor feedback signal	Circuit A shut down. Circuit	Manual	High-pressure switch open,
		Failure	does not match relay state	restarted in 1 minute. Com-		faulty control relay or CPCS
				pressor A4 not used until		board, loss of condenser air,
				alarm is reset.		liquid valve closed, opera-
						tion beyond capability.
T055	Alert	Circuit B, Compressor 1	Compressor feedback signal	Circuit B shut down.	Manual	High-pressure or loss-of-
		Failure	does not match relay state			charge switch open, faulty
						control relay or CPCS board,
						loss of condenser air, liquid
						valve closed, operation
						beyond capability.
T056	Alert	Circuit B, Compressor 2	Compressor feedback signal	Circuit B shut down. Circuit	Manual	High-pressure switch open,
		Failure	does not match relay state	restarted in 1 minute. Com-		faulty control relay or CPCS
				pressor B2 not used until		board, loss of condenser air,
				alarm is reset.		liquid valve closed, opera-
						tion beyond capability.
T057	Alert	Circuit B, Compressor 3	Compressor feedback signal	Circuit B shut down. Circuit	Manual	High-pressure switch open,
		Failure	does not match relay state	restarted in 1 minute. Com-		faulty control relay or CPCS
				pressor B3 not used until		board, loss of condenser air,
				alarm is reset.		liquid valve closed, opera-
						tion beyond capability.
A060	Alarm	Cooler Leaving Fluid	Thermistor outside range of	Chiller shutdown after	Automatic	Thermistor failure, damaged
		Thermistor Failure (T1)	–40 to 245 F (–40 to 118 C)	pumpdown complete.		cable/wire or wiring error.
A061	Alarm	Cooler Entering Fluid	Thermistor outside range of	Chiller shutdown after	Automatic	Thermistor failure, damaged
		Thermistor Failure (T2)	–40 to 245 F (–40 to 118 C)	pumpdown complete.		cable/wire or wiring error.
T064	Alert	Circuit A Saturated Con-	Thermistor outside range of	Circuit A shutdown after	Automatic	Thermistor failure, damaged
		densing Thermistor Failure	–40 to 245 F (–40 to 118 C)	pumpdown complete.		cable/wire or wiring error.
		(T3)
T065	Alert	Circuit B Saturated Con-	Thermistor outside range of	Circuit B shutdown after	Automatic	Thermistor failure, damaged
		densing Thermistor Failure	–40 to 245 F (–40 to 118 C)	pumpdown complete.		cable/wire or wiring error.
		(T4)
T066	Alert	Circuit A Saturated Suction	Thermistor outside range of	Circuit A shutdown after	Automatic	Thermistor failure, damaged
		Thermistor Failure (T5)	–40 to 245 F (–40 to 118 C)	pumpdown complete.		cable/wire or wiring error.
				(EXV only)
T067	Alert	Circuit B Saturated Suction	Thermistor outside range of	Circuit B shutdown after	Automatic	Thermistor failure, damaged
		Thermistor Failure (T6)	–40 to 245 F (–40 to 118 C)	pumpdown complete.		cable/wire or wiring error.
				(EXV only).
T068	Alert	Compressor A1 Suction	Thermistor outside range of	Circuit A shutdown after	Automatic	Thermistor failure, damaged
		Gas Thermistor Failure (T7)	–40 to 245 F (–40 to 118 C)	pumpdown complete.		cable/wire or wiring error.
				(EXV only).
T069	Alert	Compressor B1 Suction	Thermistor outside range of	Circuit B shutdown after	Automatic	Thermistor failure, damaged
		Gas Thermistor Failure (T8)	–40 to 245 F (–40 to 118 C)	pumpdown complete.		cable/wire or wiring error.
				(EXV only).

T073	Alert	Outside Air Thermistor	Thermistor outside range of	Temperature reset disabled.	Automatic	Thermistor failure, damaged
		Failure (T9)	–40 to 245 F (–40 to 118 C)	Chiller runs under normal		cable/wire or wiring error.
				control/set points.
T074	Alert	Space Temperature	Thermistor outside range of	Temperature reset disabled.	Automatic	Thermistor failure, damaged
		Thermistor Failure (T10)	–40 to 245 F (–40 to 118 C)	Chiller runs under normal		cable/wire or wiring error.
				control/set points.

T077	Alert	Circuit A Saturated	Saturated suction is	Circuit A shutdown after	Automatic	Faulty expansion valve or
		Suction Temperature	greater than leaving fluid	pumpdown complete.		EXV board, faulty cooler suc-
		exceeds Cooler Leaving	temperature for more than			tion thermistor (T5) or leav-
		Fluid Temperature	5 minutes			ing fluid thermistor (T1).
T078	Alert	Circuit B Saturated	Saturated suction is	Circuit B shutdown after	Automatic	Faulty expansion valve or
		Suction Temperature	greater than leaving fluid	pumpdown complete		EXV board, faulty cooler suc-
		exceeds Cooler Leaving	temperature for more than			tion thermistor (T6) or leav-
		Fluid Temperature	5 minutes			ing fluid thermistor (T1).
T079	Alert	Lead/Lag Thermistor Failure	Thermistor outside range of	Lead/lag algorithm runs	Automatic	Dual chiller LWT thermistor
			–40 to 245 F (–40 to 118 C)	using Master LWT sensor		failure, damaged cable/wire
				Master is lead chiller.		or wiring error.

Air Conditioner specifications

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Carrier Alarm Codes List: T051, T052, and Other Alarm Codes Explained

Models: Air Conditioner

Table 29 — Alarm and Alert Codes

T051

T052

T053

T054

T055

T056

T057

A060

A061

T064

T065

T066

T067

T068

T069

T073

T074

T077

T078

T079

Air Conditioner specifications