American Power Conversion Central Air Conditioning System Alarm messages and suggested actions

Operation: Respond to Alarms

Alarm messages and suggested actions

Displayed Alarm Message	Action Required
Air Block Interlock Open	• Verify that the air block is in place.
	• Confirm that the wiring connections for the air block interlock are secure.
Air Filter Clogged	• Verify the condition of the return air filters, and replace them if required.
	• Check the pressure drop across the filters by reviewing the System status.
	• Ensure that the pressure-sensing tubing is properly connected to the sensor.
	• Verify that the ends of the pressure-sensing tubing are not blocked or placed
	incorrectly.
	• Verify that the correct filter is selected in the System Options menu (Path:
	Main > Setup > System > System Config > System Options).
Airflow Low	• Check the pressure drop across the filters, and replace the filters if necessary.
	• Check the pressure drop across the evaporator coil on the pressures screen of
	the display interface (Path: Main Menu > Status > [Module] > Pressures).
	The reading should be close to the recommended coil differential pressure
	drops indicated in the table “Coil Differential Pressure Values” on page 17. If
	the reading is too low based on Module size and options installed, adjust the
	blower speed.
	• Verify the proper operation of the Variable Frequency Drive (VFD) and
	blower motors.
	• Verify that the VFD overload alarm is not active.
	• Ensure that any field-installed dampers in the discharge duct are open.
	• Verify that the Mode Delay is not too short. If the Mode Delay is too short,
	the Airflow Low alarm occurs after start-up and resolves itself after a few
	minutes.
Backup is Load Sharing	• A backup System is contributing to meet the room load.
	• No action required. The backup will return to idle when the demand falls.
Backup System Idle	• A primary System has come back online after a failover event.
	• No action required.
Backup System Online	• Indicates that a System failover has occurred. The backup System has come
	online due to another online System that either failed or was commanded off.
	A System Comm Loss is considered to be a System failure if the Comm
	Loss Failover configuration setting is Yes (the default setting).
	• Check the System’s event log to determine the cause of the System failure.
Blower 1 Requires Maintenance	• Verify operation of Blower 1 and perform preventive maintenance.
	• Reset the maintenance alarm for Blower 1 on the display interface.
Blower 2 Requires Maintenance	• Verify operation of Blower 2 and perform preventive maintenance.
	• Reset the maintenance alarm for Blower 2 on the display interface.
Condensate Pump Fail	• Verify that the condensate pump circuit breaker has not been tripped.
	• Ensure that the wiring between the float switch for the condensate pump and
	the controller is secure.
	• Confirm that the condensate removal lines are free of debris and are
	unobstructed.
	• Confirm the line voltage at the condensate pump.
	• Ensure that the condensate float switch is moving freely and does not bind.
	• Confirm that the condensate pump reservoir is clean and free of debris.
	• Replace the condensate pump.

40 NetworkAIR IR Operation, Maintenance, and Troubleshooting