Liebert NXC 40kVA - External Protective Device; Power Cable; LBS Cable

62 Chapter 7 Parallel System And LBS System
Liebert NXC 30kVA And 40kVA UPS User Manual
Figure 7-5 LBS system (parallel system)
Note
In a dual-bus system, the two UPS systems must have the same power rating, voltage and frequency, and the load must not
exceed the power rating of a UPS module system.
7.4.2 External Protective Device
Refer to 3.1.9 External Protective Device.
7.4.3 Power Cable
The power cable of dual-bus power system is similar to that of single system. Refer to 3.1 Wiring Of Power Cable.
7.4.4 LBS Cable
The shielded and double-insulated parallel cables are available in lengths 5m, 10m and 15m. Connect the two optional
LBS cables in a ring configuration: from the LBS1 port of one UPS module to LBS2 port of another UPS module, and
from the LBS2 port of one UPS module to LBS1 port of another UPS module, as shown in Figure 7-6 and Figure 7-7.
Figure 7-6 Connection of typical LBS system (UPS module)
STS
Q1 Q2 Q3
Q5
Q1 Q2 Q3
Q5
Parallel
cable
Q1 Q2 Q3
Q5
Q5
Q1 Q2
LBS
Q3
UPS 1 ...... UPS 4
UPS 1 ...... UPS 4
Bypass
Rectifier
Rectifier
Bypass
Rectifier
Rectifier
Parallel
cable
To load
UPS 1
UPS 2
LBS 1
PARA 1
LBS 2
PARA 2
LBS 1
LBS 2
PARA 1
PARA 2
LBS cable