
Understanding UPS Operation
7.2.2 Normal Mode – RT
Figure 7-2 shows the path of electrical power through the UPS system when the UPS is operating in Normal mode.
K5
Static
Switch
Rectifier
K1
Battery
Converter
Breakers Contactors |
|
Closed | Battery |
| Breaker |
Open
Battery
Inverter
K3
Main Power Flow
Trickle Current
Energized
Figure 7-2. Path of Current Through the UPS in Normal Mode – RT
During normal UPS operation, power for the system is derived from a utility input source through the rectifier input contactor K1. The front panel displays “Normal,” indicating the incoming power is within voltage and frequency acceptance windows.
The battery converter derives its input from the regulated DC output of the rectifier and provides either a boosted or bucked regulated DC voltage charge current to the battery. The UPS monitors the battery charge condition and reports the status on the control panel. The battery is always connected to the UPS and ready to support the inverter should the utility input become unavailable.
EATON Powerware® 9390 UPS |