Toshiba 4200FA Series, Installation And Operation Manual

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62 4200FA Installation and Operation Manual
Battery Recharging 8.7
The illustration below shows a graphical representation of the UPS battery recharge process after a full
discharge.
Figure 8-6 Battery Recharge Curve
The recharge process consists of three steps.
1. First, the charging current is maintained at approximately 4.0 amperes for the 15/25/30 kVA with
internal batteries, 10.0 amperes for the 15/25/30 kVA with internal transformer and approximately
11.5 amperes for all 50 kVA models. This current is the maximum value that can be used to
charge the batteries (for minimal recharge time) while assuring safety and long battery life.
2. Second, constant-voltage control starts and current gradually decreases as the batteries charge
to their normal fully charged state.
3. Third, a slight "trickle" current continues to flow into the batteries to keep them fully charged and
"floating" at the normal DC Voltage level. A full recharge usually requires approximately 24-72
hours (90% recharge in 10 X discharge time) after a complete discharge.
The following chart shows the rated maximum and minimum battery voltages, and the charge current for
each of the sizes while the unit is maintained in a 75 °F (24
°
C) ambient.
Rated Battery Voltages
Model
15/25/30 kVA 50 kVA
Internal
Battery
Internal
Transformer
Internal
Battery
Internal
Transformer
V float 324.0 VDC 324 VDC
V min 216 VDC 216 VDC
I charge 4.0 A 10.0 A 11.5 Amps