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5.2Configuring Parallel System Operation
5.2.1General
The NX uses intelligent and reliable decentralized technology to achieve parallel operation of two or more modules of the same rating.
The 1+N system is used to:
•Increase the reliability of the system to ensure adequate power supply to the critical load con- nected.
•Increase serviceability and allow the execution of maintenance operations and reparations with- out affecting the ordinary operating conditions of the system (depending on the redundancy level).
5.2.2Features of Parallel System
•The hardware and firmware for parallel UPS module operation is standard in the NX, and the configuration can be set up by changing the settings in configuration software.
•It is easy to install the parallel cables in a ring, providing high reliability and redundancy. And the intelligent paralleling logic provides the user with maximum flexibility. For example, shut- ting down or starting up the UPS modules in the parallel system can be done in any sequence. If an overload transfer occurs, the whole system can recover automatically from bypass mode after the overload is cleared.
•The total load of the parallel system can be queried from each module’s liquid crystal display screen.
Figure 22 1+N system block diagram
Supplied | N |
by Others |
|
Input Mains
Supply A B C
UPS 1 | CB 1 |
Rectifier
N
Input Mains
Supply A B C
UPS 2 | CB 1 |
Rectifier
Fuse |
|
1 |
|
Battery | Charger |
|
Static
Switch
Inverter
| Fuse |
|
2 |
| |
Battery | Charger | |
|
|
Static
Switch
Inverter
SW1-D
A B C
Q1Ext
QUPS
A B C
Q2Ext 
Paralleling Cabinet | QByp |
To Load
31
