Powerware 650825 kVA operation manual Rectifier, Inverter, Battery Converter

UNDERSTANDING UPS OPERATION

Bypass

Breaker

(CB4)

Bypass Input

Input

Breaker

Rectifier (CB1

Input

Rectifier

Static

Switch

K5

Inverter

Output

K1

K3

Battery

Converter

Breakers Contactors

Closed

Open

K2
Battery	Battery
Breaker	Breaker

Battery

Main Power Flow

Trickle Current

Energized

De−Energized

NOTE On an UPS configured as an IOM, the bypass input, static switch, bypass breaker (CB4), and K5 are not present.

Figure 6-2. Path of Current Through the UPS in Normal 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 Normal mode.

NOTE Bypass mode is not available on an UPS configured as an IOM.

If the UPS becomes overloaded or unavailable, the UPS switches to Bypass mode. The UPS automatically returns to Normal 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.

EATON Powerware® 9395 UPS (650–825 kVA) Installation and Operation Manual S 164201725 Rev 2 www.powerware.com 6−3