Chapter 1 Overview 1
NX UPS Single Module And Parallel System 250kVA ~ 800kVA User Manual
Chapter 1 Overview
This chapter introduces the features, design concept, parallel system, operation mode, battery management and
battery protection of NX 250kVA ~ 800kVA UPS (hereinafter referred to as UPS).
1.1 Features
The UPS is connected between the three-phase input power and the critical loads (e.g. computer) to provide high
quality three-phase power for the loads. The UPS has the following advantages:
Increase the power supply quality
The UPS protects its output against the input power change through the internal voltage and frequency controller.
Improve noise suppression
Due to the application of AC-DC-AC conversion mode, the noise in the input power is effectively filtered, and the load
gets clean power supply.
Provide mains failure protection
If the input power fails, the UPS will work in battery mode, and the power supply to the loads will not be interrupted.
1.2 Design Concept
1.2.1 System Design
As shown in Figure 1-1, the AC mains source is converted by the rectifier into DC power. The inverter converts that
DC power from the rectifier or the DC power from the battery into AC power, and provides the AC power to the load.
The battery supplies the load through the inverter in the event of a mains failure. The mains source can also supply
the load through the static bypass.
If UPS maintenance or repair is necessary, the load can be transferred without power interruption to the maintenance
bypass.
Maintenance switch Q3
Bypass switch Q2
Mains input
Bypass input
Maintenance bypass
Rectifier
Inverter
Battery
Battery charger
UPS output
Mains input switch Q1
Note:
300kVA~400kVA: The rectifier input switch (i.e, the main input switch Q1) is an option.
600kVA~800kVA: The rectifier input switch (i.e, the main input switch Q1) is provided in standard configuration.
Input
Output
250kVA~400kVA: Q1 is an optional configuration while Q2, Q3, and Q5 are standard configurations
600kVA~800kVA: Q3 is an optional configuration while Q1, Q2, and Q5 are standard configurations
Note:
500kVA~600kVA E: Q1, Q2, Q3, and Q5 are optional configurations
Figure 1-1 Operating theory of UPS module system