Carrier 69NT20-531-300 manual Controller Alarm Indications Sheet 2

	Table 3-6 Controller Alarm Indications (Sheet 2 of 4)
		Alarm 25 is triggered by the opening of the condenser motor internal protector
		and will disable all control units except for the evaporator fans. This alarm will
AL25	Condenser Fan Mo-	remain active until the motor protector resets. This alarm triggers failure action
	tor Safety	C (evaporator fan only) or D (all machinery off) of Function Code Cd29 if the
		unit has a perishable set point. Failure action D (all machinery off) is triggered if
		the unit has a frozen set point
	All Supply and Re-	Alarm 26 is triggered if the Controller determines that all of the control sensors
AL26	turn temperature	are out-of-range. This can occur for box temperatures outside the range of -50_C
	Control Sensors	to +70_C (-58_F to +158_F). This alarm triggers the failure action code set by
	Failure	Function Code Cd29.
		The Controller has a built-in Analog to Digital (A-D) converter, used to convert
		analog readings (i.e. temperature sensors, current sensors, etc.) to digital read-
AL27	A/D Accuracy Fail-	ings. The Controller continuously performs calibration tests on the A-D con-
	ure	verter. If the A-D converter fails to calibrate for 30 consecutive seconds, this
		alarm is activated.This alarm will be inactivated as soon as the A-D converter
		calibrates.
		Alarm 28 is triggered if suction pressure is below 2 psia and alarm 66 (Suction
		Pressure Transducer Failure) is not active. This alarm will be inactivated when
AL28	Low Suction Pres-	suction pressure rises above 2 psia for three continuous minutes. This alarm trig-
	sure	gers failure action C (evaporator fan only) or D (all machinery off) as determined
		by User Selectable Failure Response if the unit has a perishable set point; Failure
		action D (all machinery off) if the unit has a frozen set point. Reset SMV.
		During start-up diagnostics, the EEPROM is examined to determine validity of
		its contents. This is done by testing the set point and the alarm list. If the con-
		tents are invalid, Alarm 51 is activated. During control processing, any operation
AL51	Alarm List Failure	involving alarm list activity that results in an error will cause Alarm 51 to be ac-
		tivated. Alarm 51 is a “display only” alarm and is not written into the alarm list.
		Pressing the ENTER key when “CLEAr” is displayed will result in an attempt to
		clear the alarm list. If that action is successful (all alarms are inactive), Alarm 51
		will be reset.
		Alarm 52 is activated whenever the alarm list is determined to be full; at start-up
AL52	Alarm List Full	or after recording an alarm in the list. Alarm 52 is displayed, but is not recorded
		in the alarm list. This alarm can be reset by clearing the alarm list. This can be
		done only if all alarms written in the list are inactive.
		Alarm 53 is caused by the battery pack charge being too low to provide sufficient
AL53	Battery Pack Failure	power for battery-backed recording. Renew replaceable batteries. If this alarm
		occurs on start up, allow a unit fitted with rechargeable batteries to operate for up
		to 24 hours to charge rechargeable batteries sufficiently to deactivate the alarm
		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
	Primary Supply	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
AL54	Temperature Sensor
		secondary supply temperature sensor, and AL54 is activated, the primary return
	Failure (STS)
		sensor reading, minus 2_C will be used for control.
		NOTE
		The P5 Pre-Trip test must be run to inactivate the alarm
	DataCORDER	This alarm activates to indicate the DataCORDER has a software failure. To
AL55		clear this alarm, reconfigure the unit to the current model number. This failure
	Failure	may be the result of a voltage dip in access of 25%.

T-309 3-18