Battery Backup Mode - Toshiba 4200FA User Manual

6.1.3

Battery Backup Mode

The following illustration shows power flow during the battery backup mode. In the event of
an AC power failure the batteries of the UPS instantly begin supplying DC power to the UPS
to the main inverter circuit. This circuit converts the DC power into AC power. The AC power
is available at the output of the unit. This back-up process will continue until the UPS battery
voltage drops below a specific minimum level. At which time the batteries cease supplying
power to the load.
This minimum level is the shutdown voltage minimum (V min). The rated battery voltage
table on page 33 shows (V min). The battery backup time and discharge process is
explained in Section 6.2.
Power Flow
Isolating
XFMR
Input
Power
Power flow in battery backup mode for the 4200FA 75/80 kVA UPS
T O S H I B A
MCCB
Converter
37
Static
Bypass
Inverter
Charger/
Chopper
External
Batteries
Output
Power