Emerson 60HZ - Manual (Page 37)

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5.2 Configuring Parallel System Operation
5.2.1 General
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).
5.2.2 Features 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
QUPS Paralleling Cabinet
B
a
tt
er
y 1
Charger
Fuse
UPS 1 CB 1
Rectifier
Static
Switch
Inverter
SW
1-
C
SW
1-
D
SW1-A
A B C
Q1Ext
B
a
tte
ry
2
Charger
Fuse
UPS 2 CB 1
Rectifier
Static
Switch
Inverter
SW
1
-C
SW
1
-D
SW1-A
A B C
Q2Ext
To Load
QByp
Input Mains
Supply A B C
Input Mains
Supply A B C
N
Supplied
by Others
N