6.2.1Normal Mode

Figure 6---2 shows the path of electrical power through the UPS system when the UPS is operating in Normal mode.

NORMAL MODE

 

 

STATIC

MAINTENANCE

K5

SWITCH

BYPASS SWITCH

 

RECTIFIER

BOOST

INVERTER

CONVERTER

CB1 K1

K3

 

 

 

MAINTENANCE

 

 

BYPASS SWITCH

CHARGER

K2

 

 

 

Main Power Flow

Breakers Contactors

 

Closed

CB2

 

Open

 

BATTERY

Trickle Current

Energized

De--Energized

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

During normal UPS operation, power for the system is derived from a utility input source through the input breaker CB1 and contactor K1. ”Normal” appears on the front panel and indicates the incoming power is within voltage and frequency acceptance windows. Three phase AC input power is converted to DC using a full---wave, six---pulse, solid---state rectifier block which supplies unregulated DC voltage to a boost converter which in turn supplies a higher and regulated DC voltage to the inverter. The battery is not charged directly from the unregulated rectifier. Instead, a separate battery charger is used to maintain the proper charge level on the battery during normal operation.

6--4

Powerware 9330 (10 kVA--40 kVA) Installation and Operation

 

164201300 REV. G 061502

Page 78
Image 78
Powerware 9330 operation manual Normal Mode