MGE UPS Systems Comet Series Installation And User Manual page 45

3.4.2.2 Return of AC Power
3.4.3 Overload
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Installation and Users Manual
indications. It warns the user of upcoming battery shutdown
at a user-determined level of remaining power.
On the UPS itself, the buzzer beeps louder and more rapidly,
and the yellow "Battery Status" LED flashes rapidly.
The end of battery power occurs when the battery reaches
shutdown level. At this point, the Inverter shuts down and the
UPS goes into "Stand-By" mode. Load is no longer
supported. If the input AC power does not return to within
tolerance within approximately 2 hours, the unit will
shutdown.
Once input AC power returns, the batteries begin their
charging cycle. It takes approximately 10 hours of online
operation to restore 10 minutes of backup time.
When the AC input power failure ends or power returns
to within tolerances:
• If the end of battery backup power was not reached, the
Comet returns to normal operating mode.
• If the end of battery backup power was reached and
unit is in "Stand-By" mode, the Rectifier and the Inverter
automatically start up (the inverter must be manually
started if the system is in manual start-up mode).
• If the end of "Stand-By" mode was reached, follow the
Start-up procedure.
When an Inverter temporary overload occurs, the load is
transferred to the "Static Switch". Return to normal mode of
operation is automatic, following elimination of the overload.
The Inverter can handle a continuous overload for a given
duration depending on the size of the output current overload
or the output power overload (see Figure 3-6).
When an overload occurs:
• The buzzer sounds.
• The yellow "Fault" LED goes on.
• The Inverter shuts down at the end of its corresponding
overload time.
• The load is supplied by AC input power via the "Static
Switch".
• The green "Load Protected" LED goes off.
• The red "Load Not Protected" LED goes on.
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