General Description; Introduction; Figure 1 Single Module Block Diagram (Dual Input Configuration) - Liebert NX series Operation & Maintenance Manual

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ENERAL
1.1

Introduction

Liebert's NX™ Uninterruptible Power Supply system provides continuous, high-quality AC power to
your business-critical equipment, such as telecommunications and data processing equipment. The
NX UPS supplies power that is free of the disturbances and variations in voltage and frequency com-
mon to utility power, which is subject to brownouts, blackouts, surges and sags.
The NX utilizes the latest in high-frequency, double-conversion pulse width modulation (PWM) tech-
nology and fully digital controls to enhance its reliability and increase the ease of use.
The standard Liebert NX consists of the UPS and internal batteries in a compact, single cabinet.
As shown in Figure 1, the AC utility source is input at CB1 and the rectifier converts the AC utility
into DC power. The inverter converts that DC power from the utility—or DC power from the batter-
ies—into AC power for the load. The batteries power the load through the inverter in the event of a
power failure. The utility source can also power the load through the static bypass.
If maintenance or repair of the UPS is necessary, the load can be switched without interruption in
service to the maintenance bypass.
Figure 1 Single module block diagram (dual input configuration)
Bypass Input
AC Utility Input
CB1
Neutral Wire
ESCRIPTION
SW1/D
SW1/C
Contactor
Rectifier
Discharge
Battery
Maintenance Bypass
Static Switch
Contactor
Inverter
Battery
Charger
1

General Description

UPS Output
SW1/A
Neutral Wire
SW1/B