Energy Saver System Mode - Eaton Power Xpert 9395 Series Installation And Operation Manual

Bypass Input
Input
Breaker
Rectifier
(CB1
Input
K1 K1
Breakers Breakers Contactors Contactors
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.
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.
6.2.3

Energy Saver System Mode

NOTE
When the UPS is operating in ESS mode, commercial AC power is supplied directly to the critical load through
the continuous static switch. Power line filtering and spike protection for the load are provided by the input and
output filter networks, and the UPS actively monitors the critical bus for power disturbances. When in this
mode, the input and output contactors are closed and the link is maintained through the diode bridge.
Static Static
Switch Switch
R R c e c e f i t f i t r e i r e i
Battery
Converter
Closed Closed
Open Open
Battery
VMMS and ESS modes are mutually exclusive. If ESS mode is enabled, VMMS
mode is disabled.
TM
Power Xpert 9395 UPS (300 kVA) Installation and Operation Manual 164201728—Rev 10
K5
I I v n v n r e r e r e t r e t
K2
Battery
Breaker
Understanding UPS Operation
Output
K3 K3
Main Power Flow Main Power Flow
Trickle Current Trickle Current
Energized Energized
De-Energized De-Energized
6-3