Liebert Emerson NX UPS System - Manual (Page 49)

Operation
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5.1.4 Redundant Control Power Supply Board
The UPS is equipped with two identical and fully redundant control power supply boards. Each of
them takes inputs from the AC and DC sources. When one of the sources or even if one of the control
power boards fails, the UPS system can still operate normally. This feature further enhances the reli-
ability of the system.
5.1.5 Socket Outlet
One single-phase Shuko-type universal outlet of 3A current handling capability provides nominal
UPS output voltage of up to 3A current capacity for the ease of testing, commissioning & servicing of
the UPS.
5.2 Multi Module UPS—1+N
Multi-module UPS are formed by several “single unit” UPS modules to constitute “1+N”system where
groups of one or more, up to six, single units operate together for the purpose of providing additional
power or reliability or both. The load is equally shared between any paralleled UPS.
Figure 29 1+N multi-module UPS with external maintenance bypass switch
Further, single unit or 1+N groups may be configured as “distributed redundant” systems with inde-
pendent outputs that nevertheless are synchronised through a Load Bus Synchroniser (LBS) so that
critical loads can be seamlessly transferred from one system to another. See 5.3 - Modes of Opera-
tion for more information.
CB1
UPS1
OUTPUT
Qout all UPS
Qout UPS1 Qout UPS2
Qout Byp
Qin Ext
Byp
Qin UPS2 Qin UPS3 Qin UPS1
Qout UPS3
RECTIFIER
STATIC
SWITCH
INVERTER
L1,L2,L3,N L1,L2,L3,N L1,L2,L3,N L1,L2,L3,N L1,L2,L3,N L1,L2,L3,N
L1,L2,L3,N L1,L2,L3,N L1,L2,L3,N
Supplied by Others
Input Mains Supply Input Mains Supply Input Mains Supply
Bypass Mains Supply
Distribution Cabinet
Bypass Mains Supply
CB1
UPS2
OUTPUT
RECTIFIER
STATIC
SWITCH
INVERTER
CB1
UPS3
OUTPUT
RECTIFIER
STATIC
SWITCH
INVERTER