Powerware 10001100 kVA operation manual Bypass Mode, 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

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

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.

6.2.3Bypass Mode

The UPS automatically switches to Bypass mode if it detects an overload, load fault, or internal failure. The UPS can also be transfered from Normal mode to Bypass mode manually. The bypass source supplies the commercial AC power to the load directly. Figure 6-3shows the path of electrical power through the UPS system when operating in Bypass mode.

C A U T I O N

The critical load is not protected while the UPS is in Bypass mode.

In Bypass mode, the output of the system is provided with three−phase AC power directly from the system input. While in this mode, the output of the system is not protected from voltage or frequency fluctuations or power outages from the source. Some power line filtering and spike protection is provided to the load but no active power conditioning or battery support is available to the output of the system in the Bypass mode of operation.

EATON Powerware® 9395 UPS (1000–1100 kVA) Installation and Operation Manual S 164201764 Rev 1 www.powerware.com 6−3