TOSHIBA
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5.8 Battery Backup Time and Discharge Process
The UPS system, when used in conjunction with a Toshiba designed Battery System, is
designed to provide several minutes of back-up time (Refer to the Battery System Manual for
back-up times). These times are valid when the unit is operating under full load. When these
models are operating at half load, the batteries can provide approximately 2 times the specified
value. 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.
CAUTION Contact Toshiba when using other than Toshiba designed Battery Systems to
determine proper compliance. Using other systems could void Warranty and or
Safety Certifications.
The following illustration graphically shows the battery discharge process at full load
conditions.
5.9 Battery Low Voltage Tolerances
Excessive discharge will cause the UPS battery voltage to drop bellow tolerable levels. The
chart shown below lists the voltage level at which each UPS unit's low-voltage alarm will
sound, and also at what level the low-voltage condition will cause the unit to automatically shut
down.
Models 15/25/30/33/50 kVA
Nominal Voltage 288 VDC
Alarm Voltage 252 VDC
Shutdown Voltage min. 216 VDC