Carrier 48/50AJ specifications Alert and Alarm Codes cont

Table 114 — Alert and Alarm Codes (cont)

ALARM
OR			DESCRIPTION				ACTION TAKEN BY CONTROL	RESET	PROBABLE CAUSE
ALERT								METHOD
NUMBER
T300			Space Temperature Below Limit				Stop cooling, but continue	Automatic	Outdoor dampers stuck, no load
							to heat
T301			Space Temperature Above Limit				Stop heating, but continue	Automatic	High load, dampers open
							to cool
T302			Supply Temperature Below Limit				Continue to run unit	Automatic	Dampers open, check configuration
									setpoint
T303			Supply Temperature Above Limit				Continue to run unit	Automatic	Dampers open, check configuration
									setpoint
T304			Return Temperature Below Limit				Continue to run unit	Automatic	Dampers open, check configuration
									setpoint
T305			Return Temperature Above Limit				Continue to run unit	Automatic	Dampers open, check configuration
									setpoint
T308			Return Air Relative Humidity Below Limit				Alert	Automatic	Configuration error, or sensor error
T309			Return Air Relative Humidity Above Limit				Continue to run unit	Automatic	Dampers open, check configuration
									setpoint
T310			Supply Duct Static Pressure Below Limit				Continue to run unit	Automatic	VFD problem, broken fan belt
T311			Supply Duct Static Pressure Above Limit				Continue to run unit	Automatic	VFD problem, broken fan belt
T312			Building Static Pressure Below Limit				Continue to run unit	Automatic	Exhaust issues, check setpoint
T313			Building Static Pressure Above Limit				Continue to run unit	Automatic	Exhaust issues, check setpoint
T314			IAQ Above Limit				Continue to run unit	Automatic	Damper or IAQ control issues
A404			Fire Shut Down Emergency Mode (fire-smoke)				Unit Shutdown	Automatic	Smoke detector switch or external
									switch
A405			Evacuation Emergency Mode				Run power exhaust	Automatic	Special fire mode control
A406			Pressurization Emergency Mode				Run supply fan	Automatic	Special fire mode control
A407			Smoke Purge Emergency Mode				Run supply and exhaust fans	Automatic	Special fire mode control
T408			Dirty Air Filter				Continue to run unit	Automatic	Dirty filter, switch setting
A409			Supply Fan Status Failure				Stop unit	Automatic	Fan drive failure
T409			Supply Fan Status Failure				Continue to run unit	Automatic	Fan drive failure, or sensor failure
T414			Loss of Communication with the Belimo Actuator				Close economizer	Automatic	Calibrate economizer, economizer
									failure, wiring
T414			Belimo Actuator Direction Error				Close economizer	Automatic	Motor direction switch wrong, wiring
T414			Belimo Actuator Failure				Attempt to close economizer	Automatic	Motor failure
T414			Belimo Actuator Jammed				Close economizer	Automatic	Obstruction in damper
T414			Belimo Actuator Range Error				Close economizer	Automatic	Calibrate economizer
T420			R-W1 Jumper Must Be Installed to Run Heat in Service				No heat	Automatic	Add red wire jumpers
			Test
T421			Thermostat Y2 Input ON without Y1 ON				Assume Y2 is Y1	Automatic	Thermostat wiring error
T422			Thermostat W2 Input ON without W1 ON				Assume W2 is W1	Automatic	Thermostat wiring error
T423			Thermostat Y and W Inputs ON				Alert	Automatic	Thermostat issues
T424			Thermostat G Input OFF on a Call for Cooling				Turn fan on	Automatic	Thermostat or wiring issues
T500			Current Sensor Board Failure - A1				Stop compressor A1	Automatic	Faulty board or wiring
T501			Current Sensor Board Failure - A2				Stop compressor A2	Automatic	Faulty board or wiring
T502			Current Sensor Board Failure - B1				Stop compressor B1	Automatic	Faulty board or wiring
T503			Current Sensor Board Failure - B2				Stop compressor B2	Automatic	Faulty board or wiring
A700			Supply Air Temperature Sensor Failure				Stop staged gas heat	Automatic	Faulty sensor or wiring error
T701			Staged Gas Thermistor 1 Failure				Stop staged gas heat	Automatic	Faulty sensor or wiring error
T702			Staged Gas Thermistor 2 Failure				Stop staged gas heat	Automatic	Faulty sensor or wiring error
T703			Staged Gas Thermistor 3 Failure				Stop staged gas heat	Automatic	Faulty sensor or wiring error
A704			Staged Gas Leaving Air Temp Sum Total Failure				Stop staged gas heat	Automatic	Faulty sensor or wiring error
T705			Limit Switch Thermistor Failure				Stop staged gas heat	Automatic	Faulty switch or wiring
			LEGEND
Axxx —		Alarm		Pxxx —		Pre-Alert
CEM	—	Controls Expansion module		Txxx	—	Alert
IAQ	—	Indoor Air Quality		TXV	—	Thermostatic Expansion Valve
OAT	—	Outdoor Air Temperature		VFD	—	Variable Frequency Drive

For 48/50A2,A3,A4,A5 units:

•Compressor internal overload protector is open. Internal overload protectors are used in the Copeland compressors in all units except size 60 ton units with voltages of 208/230-v, 380-v, and 575-v.

•Compressor external overload protector (Kriwan module) has activated. The Copeland compressors in size 60 ton units with voltages of 208/230-v, 380-v, and 575-v use external overload protector modules that are mounted in the compressor wiring junction box. Temperature sensors embedded in the compressor motor windings are the inputs to the module. The module is powered with 120 vac from the units main control box. The module output is a normally closed contact that is wired in series with the compressor contactor coil. In a compressor motor overload condition, the contact opens de-energizing the compressor contactor.

•Circuit breaker trip. The compressors are protected from short circuit by a breaker in the control box. On the 020-050

size units there is one breaker per two compressors and on the 060 size units there is one breaker per compressor.

•Wiring Error. A wiring error might not allow the compres- sor to start.

To check out alerts 051, 052, 055 and 056:

1.Turn on the compressor in question using Service Test mode. If the compressor does not start, then most likely the problem is one of the following: HPS open, open internal protection, circuit breaker trip, incorrect safety wiring, or incorrect compressor wiring.

2.If the compressor does start verify it is rotating in the correct direction.

IMPORTANT: Prolonged operation in the wrong direction can damage the compressor. Correct rotation can be veri- fied by a gage set and looking for a differential pressure rise on start-up.

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