User Manual 10H52188UM60 - Rev. 2 - 09/2012 37
Liebert NXC Parallel UPS Installation And Commissioning
Warning
1. The default setting for DIP switch is ‘1’. However, you should set the DIP switch position for the parallel system according to the
description listed in Table 4-1. Otherwise, the UPS fault will occur.
2. The parallel address must be unique for each UPS unit.
4.3.3 Connecting external Battery Cables
All the UPS in parallel system can either share the battery strings, or use battery strings independently.
Note
Each UPS should be equipped with the independent battery MCB. Refer to Table 3-3 for selection of the battery MCB.
Using battery string independently
When each UPS of the parallel system uses the battery string independently, the battery cable connection of each UPS in
parallel system is the same as that of the single UPS, refer to 3.4.2. The schematic diagram of battery strings in 1 + 1 parallel
system when using battery strings independently is shown in Figure 4-3.
Note
Make sure that the LCD settings are correct when using the battery strings independently, refer to 4.4.2 for details.
Figure 4-3 Connection principle diagram upon using battery strings independently
Sharing battery string
Using the shared battery string in parallel system can reduce equipment costs.
Note
To ensure the abundant backup time of the battery, it is recommended to use the external battery cabinet with larger capacity.
1. Wiring
Power off the parallel system completely, disconnect the battery MCBs of all single UPS, and then use battery cables (refer to
3.4 for the cables and the MCBs) to connect ‘+’, ‘N’, ‘-’ and ‘PE’ terminals of the battery string respectively to ‘Bat +’, ‘Bat N’,
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