Press and hold, for 2 second, the RUN button on the touchscreen to begin UPS operation.
Press the Quick View button on the Quick Access Toolbar and verify the UPS has input/output power. If the UPS has
backup batteries, verify the batteries are being charged.
Stop the UPS with Internal MBS (Switch to Bypass)
Same as Standard UPS procedure.
Restore System Power after an EPO Shutdown
After shutting down the UPS by pressing the EPO switch, restore system power as follows:
1. Ensure the cause of the EPO action has been resolved.
2. Reset the UPS main circuit breaker MCCB, located behind the UPS front door, by first switching the breaker
OFF, then ON.
3. Reset the Battery Cabinet (if any) circuit breaker(s) by first switching the breaker OFF, then ON.
4. Continue the startup procedure as given in "Start the UPS with Internal MBS".
Battery Backup Time and Discharge Process
The optional battery cabinet provides some period of back-up time depending on the UPS kVA rating and system load.
The exact length of these times will depend on the UPS model used, condition of the batteries, amount and type of load,
temperature and other variables.
Figure 13.1 graphically illustrates the battery discharge process under full load conditions.
The UPS battery voltage to drops as the battery discharges. The chart in Figure 13.1 lists the voltage level at which each
UPS low-voltage alarm will sound and at what level the low-voltage condition will cause the unit to automatically shut down.
4400 Series Installation and Operation Manual – 64527-008
Nominal voltage (V
Alarm voltage (V
Shutdown voltage (V
FIGURE 13.1: TYPICAL BATTERY DISCHARGE CURVE