Figure 6‐2. Path Of Current Through The Ups In Online Mode - Eaton Power Xpert Plus 1 Installation And Operation Manual

Bypass Input
Input
Breaker
Rectifier
(CB1
Input
K1 K1
Breakers Breakers Contactors Contactors
NOTE On a UPS configured as an IOM, the bypass input, static switch, and K5 are not present.
t
Power Xpert 9395 UPS (450–550 kVA) Installation and Operation Manual
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 battery is always connected to the UPS and ready to support the inverter
should the utility input become unavailable.
Static Static
Switch Switch
Rectifier Rectifier
Battery
Converter
Closed Closed
Open Open
Battery
Figure 6‐2. Path of Current Through the UPS in Online Mode
The inverter produces a three-phase AC output to a customer's load without the use
of a transformer. The inverter derives regulated DC from the rectifier and uses IGBT
devices and pulse-width modulation (PWM) to produce a regulated and filtered AC
output. The AC output of the inverter is delivered to the system output through the
output contactor K3.
If the utility AC power is interrupted or is out of specification, the UPS automatically
switches to Battery mode to support the critical load without interruption. When utility
power returns, the UPS returns to Online mode.
NOTE
Bypass mode is not available on a UPS configured as an IOM.
If the UPS becomes overloaded or unavailable, the UPS switches to Bypass mode.
The UPS automatically returns to Online mode when the overload condition is cleared
and system operation is restored within specified limits.
If the UPS suffers an internal failure, it switches automatically to Bypass mode and
remains in that mode until the failure is corrected and the UPS is back in service.
UNDERSTANDING UPS OPERATION
K5
Inverter Inverter
K2
Battery
Breaker
S
164201701 Rev 3 www.eaton.com/powerquality
Output
K3 K3
Main Power Flow Main Power Flow
Trickle Current Trickle Current
Energized Energized
De-Energized De-Energized
6-3