TOSHIBA
5.0Operating the UPS
5.1 Operation Modes
5.1.1 AC Input Mode (normal operation)
Power
input plug
Fuse
Bypass circuit
UPS
receptacles (rear panel)
UPS main circuit
Transformer |
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| |
| (Plus Series) | |
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UPS batteries | + | = power flow | |
- | |||
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Power flow in AC input mode
The above illustration shows circuit power flow in the ac input mode. The UPS unit's rectifier, included in a boost chopper circuit, converts ac input power to dc power. This dc power runs the unit's transistor inverter and charges the batteries. The boost chopper circuit maintains a constant voltage, with current limiting, for charging the batteries and assures proper sine waveform generation for the output current. The unit's batteries are maintained in a constantly charged state when the UPS is in the normal operation mode. On the front panel, LED's labeled "On Line" and "AC Input" should be on and the "Fault" LED should be off
(See Section 9.2 Panel Layout).
5.1.2Battery Backup Mode
Power
input plug
Fuse
Bypass circuit | UPS |
| |
| receptacles |
| (rear panel) |
UPS main circuit
Transformer | |
| (Plus Series) |
+
UPS batteries
-
= power flow
Power flow in battery backup mode
The above illustration shows circuit power flow in battery backup mode. When commercial ac power failures occur, the UPS's batteries instantly begin supplying dc voltage to the UPS's main inverter circuit. This circuit changes (inverts) the dc power into ac power. The ac power is available at the unit's output receptacles. This
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