Auxiliary Control Wiring; Parallel Control Cables - Liebert NX 30 User Manual

Liebert NX

3.2.4 Auxiliary Control Wiring

Auxiliary wiring must be installed as shown in Figure 3-3 to protect the system and enable a single UPS to be isolated and tested
during service. Refer to 1.8.3 Maintenance Switch and Output Switch State Port for auxiliary contact details.

3.2.5 Parallel Control Cables

Shielded and double-insulated parallel control cables available in lengths of 5 m, 10 m and 15 m must be interconnected in a ring
configuration between the UPS modules, as shown in Figure 3-4. The parallel ports J2 and J3 are provided on the front panel of the
bypass module, as shown in Figure 3-5. The ring connection ensures the reliability of the control of the parallel system. Be sure that
the cables are connected correctly before starting up the system!
J2
J3
J4
30
UPS 1
J9
1 4 3
Q1Ext
QUPS
To load
Figure 3-3 Auxiliary Control Wiring
UPS 1
UPS 2
J2
J3
Figure 3-4 Connection of Parallel Control Cables of 1+N Parallel System
Figure 3-5 Locations of Ports J2, J3 and J4 on Bypass Module
Input distribution
UPS 2
J9 J9
1 4 3
Q2Ext
Distribution panel
UPS 3
J2
J3
User Manual 10H52192UM60 - Rev. 1 - 09/2011
Installing Parallel Systems
UPS 3
1 4 3
Q2Ext
QByp
UPS 4
J2
J3
J2
J3