Liebert NX 30 User Manual

User Manual 10H52192UM60 - Rev. 1 - 09/2011 29
Installing Parallel Systems Liebert NX
Qout of allUPS
Rectifier
L1, L2, L3, N
UPS 1 output
Qout UPS1
Supplied by others
Qin
UPS1
Mains input
Qout UPS2
Qin
UPS2
Qout UPS3
Qin
UPS3
Qin Ext
Byp
Qout BYP
L1, L2, L3, N
L1, L2, L3,
N
L1, L2, L3, N
L1, L2, L3,
N
L1, L2, L3
L1, L2, L3, N
L1, L2, L3, N
L1, L2, L3, N
Mains input
Bypass input
Bypass input
Mains input
Bypass
input L1,
L2, L3,N
STS
Inverter
Rectifier
STS
Inverter
Rectifier
STS
Inverter
UPS 2 output UPS 3 output
Output distribution
Figure 3-2 1 + N UPS System with External Maintenance Switch
Note
For 1+N installations, an external bypass rated for the total system load must be installed and the UPS internal maintenance bypass
must be locked to prevent it from being operated.
For parallel systems with 3 or 4 UPS with redundancy, and parallel systems with 2 or more UPS without redundancy, you should
install bypass load sharing inductors to optimize current sharing during static bypass operation.
3.2.2 External Protective Device
Refer to Chapter 1 Installing the UPS Module.
3.2.3 Power Cable
The wiring of the power cable is similar to that of the UPS module. The bypass and main input supplies must use the same neutral
line input terminal. If the input has a current leakage protection device, it must be fitted upstream of the common neutral sinking
point. Refer to Chapter 1 Installing the UPS Module.
Note
The length and specification of power cables, including the bypass input cables and UPS output cables, should be the same. This
facilitates load sharing in bypass mode.

Liebert NX 30 Specifications

General

Brand	Liebert
Model	NX 30
Category	Power Supply
Language	English