Normal Mode; Figure 5-2. Path Of Current Through The Ups In Normal Mode - Powerware 9335 Installation And Operation Manual

5.2.1 Normal Mode

Figure 5–2 shows the path of electrical power through the UPS system when the UPS is
operating in Normal mode.
K1
Breaker
Closed
Open
Figure 5–2. 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 contactor K1 (and externally protected utility feed). "Load Protected"
appears on the LCD display 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, regulated DC voltage to the inverter.
A separate internal battery charger is used to maintain the proper charge level on the
battery during normal operation. The battery charger derives its input from the booster
output and provides regulated DC voltage and charge current to the battery. The battery
charge condition is monitored by the UPS and, when abnormal, reported by the status
indicators located on the LCD display. The battery is always connected to the UPS and
ready to support the inverter should the utility input become unavailable.
5-4
Normal Mode
K4
Input Filter Rectifier
F1
Contactors Switches
Powerware 9335 (80 kVA and 120 kVA) Installation and Operation
IA1
Static Switch
Booster Inverter
Battery
Charger
Battery
Breaker
Battery
K2 IA2
Main Power
Trickle Current
Energized
De-Energized
164201396 REV A 071103