4 Chapter 1 Product Introduction
Liebert
®
ITA 5kVA And 6kVA UPS User Manual
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Bypass input
Main input
Output
Normal mode Bypass mode
Battery mode Maintenance Bypass mode
Figure 1-5 Operation schematic diagram
For the LED indicators introduced in this section, refer to
4.1.1 UPS State Indicators.
1.5.1 Normal Mode
When the mains input is normal, the load is supplied with voltage-stabilizing and frequency-stabilizing power by the
mains after processing of the rectifier and the inverter, and meanwhile, the charger is charging the battery, the
operation mode is Normal mode. In Normal mode, the MAINS indicator and the INVERTER indicator are on.
1.5.2 Bypass Mode
If the overload overtime, inverter or rectifier failure appears during the UPS operation in Normal mode, the UPS will
transfer to Bypass mode, that is, the load is powered by the bypass source, which comes directly from the mains input.
If the rectifier is normal, the internal charger will charge the battery. In Bypass mode, the INVERTER indicator is off;
the MAINS indicator and the INVERTER indicator are on.