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101
10.12 Auto Restart
When the main and bypass sources fail, the UPS draws power from the battery system to supply the
load until the batteries are depleted. When the UPS reaches its end of discharge (EOD) threshold, it
will shut down.
The UPS will automatically restart and enable output power:
• after utility power is restored
• if “Auto Recovery after EOD Enabling” is enabled in the UPS configuration (set by factory or by
Liebert Services)
• after the “Auto Recovery after EOD Delay Time” expires (the default delay is 10 minutes)
During the auto recovery delay, the Liebert
®
APM
™
will be charging its batteries to provide a
safety margin for equipment shutdown if input power fails again.
If the “Auto Recovery after EOD Enabling” feature is disabled, the system must be restarted manually.
10.13 Reset After Shutdown for Emergency Stop (EPO Action) or Other Conditions
Once all appropriate measures have been taken to correct the problem indicated by the alarm
message appearing on the Operator Control Panel , carry out this procedure to restore the UPS to
regular operation following an EPO action or for the following reasons: Inverter Overtemperature,
Cut-off Overload, Battery Overvoltage, excessive switching (BYP: XFER COUNT BLOCK), etc.
When the user confirms that the fault is cleared:
1. Press the FAULT CLEAR button to let the system exit the emergency off state.
2. Press the INVERTER ON button on the right side of the Operator Control Panel for longer than
2 seconds (after the rectifier has qualified).
After the EPO button is pressed, if the input utility is removed, the UPS will shut down completely.
When input utility is restored, the EPO condition will clear, and the UPS will enable the static bypass
and restore the output.
10.14 Battery Protection
10.14.1Battery Undervoltage Warning
Before the end of discharge, the Liebert
®
APM
™
displays a low battery warning. After this warning,
the battery has the capacity for 5 minutes discharging with full load (default time). The Liebert APM
can be user-configured to display this warning from 3 to 60 minutes before end-of-discharge.
10.14.2Battery End-of-Discharge (EOD) Protection
If the battery voltage is lower than the end-of-discharge voltage, the battery converter will be shut
down.
10.15 Replacing Dust Filters
Installing the two dust filter sizes in a Liebert APM requires only a Phillips screwdriver. Each filter is
held in place by a bracket on either side of each filter. To replace each filter:
1. Open the UPS front door and locate the filters on the back side of the front door (see Figure 66).
2. Remove one bracket and loosen the screw on the second bracket. The second bracket need not be
removed.
3. Remove the dust filter to be replaced.
4. Insert the clean filter.
5. Reinstall the bracket, tightening the screw securely.
6. Tighten the screw on the second bracket.
NOTE
The rectifier will start automatically 5 minutes after the of overtemperature fault is cleared.