Battery Backup Mode - Toshiba 4200FA Installation And Operation Manual

6.4

Battery Backup Mode

The following illustration shows power flow during the battery backup mode. When
commercial AC power failures occur, the batteries instantly begin supplying DC voltage to
the main inverter circuit. This circuit inverts (hence; Inverter) the DC power into AC power.
The AC power is available at the output. This back-up process will continue until the
battery voltage drops below a specific minimum level. When this occurs, the batteries will
stop supplying power to the load. This minimum level is the rated minimum voltage (V min).
Isolating
XFMR
4200FA Installation and Operation Manual
(Not available for LT units)
MCCB
Converter
Power flow in battery backup mode
MBS
Bypass
Inverter
Charger/
Chopper
External
Batteries
Output
Power
45