Connecting Power Cables; Connecting I/O Cables - Emerson Liebert ITA User Manual

28 Chapter 3 Parallel UPS Installation And Commissioning

3.4 Connecting Power Cables

Each single UPS of the parallel system needs to configure the MCB and cables respectively, refer to 2.5 Connecting
Power Cables for the specification. The recommended configurations of the total power cables are listed in Table 3-1
for the parallel system.
Table 3-1 Input & output cable CSA for the parallel system (unit: mm
Single input
Parallel UPS
number
2 units
3 units
4 units

3.4.1 Connecting I/O Cables

The power cables of the UPS are connected to the I/O terminal block of the rear panel of the UPS, the layout of the
I/O terminal block is shown in Figure 2-13.
Power distribution mode
There are two modes for UPS parallel power distribution: using the 1 + 1 parallel POD (optional) provided by
Emerson, self-distribution.
The I/O cable connections are divided into four types: 3-in 3-out, common source configuration (factory default), 3-in
3-out, split-bypass configuration, 3-in 1-out, common source configuration, 3-in 1-out, split-bypass configuration. The
I/O cable connection procedures of the four self- distribution modes are as follows.
1. Using parallel POD power distribution
It is recommended to use 1 + 1 parallel POD power distribution mode if you need 1 + 1 parallel system, for the
installation and commissioning, refer to Liebert
Manual.
2. Self-distribution for the parallel system
When the UPS number of the parallel system is more than two, use self-distribution mode.
The block diagram of three UPSs parallel system is shown in Figure 3-2. Refer to Power distribution mode in
2.5.1 Connecting I/O cables for the cable connection of each UPS. Refer to 2.5 Connecting Power Cables for the
input and output MCB, the battery MCB and the cables when using the self-distribution mode.
1 + 1 parallel
POD (1 pcs)
UPS (2 pcs)
Figure 3-1 1 + 1 parallel system installation (without battery module)
3-in 3-out
Single output
cable for cable for
parallel parallel
system system
25 25
35 35
50 50
Liebert ITA 16kVA And 20kVA UPS User Manual
®
Total neutral Grounding
line for cable for
parallel parallel
system system
35 16
50 16
70 25
ITA 16kVA And 20kVA UPS Power Output Distribution Unit User
®
2 ℃
, ambient temperature: 25
3-in 1-out
Total output Total neutral
cable for line for
parallel parallel
system system
70 120
150 240
240 370
)
Grounding
cable for
parallel
system
35
75
120