Wiring Of Signal Cable; Overview - Liebert NXC 30kVA User Manual

connected correspondingly. Connect the input neutral line to the neutral terminal N in the cabinet. Ensure correct
phase rotation.
2) Remove the three shorting copper bars between the rectifier input terminals (mA-mB-mC) and the bypass terminal
terminals (bA-bB-bC). Connect the rectifier input cables to the rectifier input terminals (mA-mB-mC) in the cabinet, and
connect the bypass input cables to the bypass input terminals (bA-bB-bC) in the cabinet. Connect the rectifier input
neutral line and bypass neutral line to the neutral terminal N in the cabinet. Ensure correct phase rotation.
4. Connect the system output cables between the output terminals (oA-oB-oC-oN) in the cabinet and the load. Refer to
Table 3-1 for the torque. Ensure correct phase rotation.
If the load will not be ready to accept power supply before arrival of the service engineer, ensure that the system output cables are
safely isolated at their ends.
5. If the external battery is required, ensure correct polarity of the connections from the battery string terminals to the
BCB and from the BCB to the battery input terminals (BAT+, BAT N, BAT-) in the UPS cabinet, that is, (BAT+) to (+)
and (BAT-) to (-), (BAT N) to (N), but disconnect one or more battery cell links in each tier. Do not reconnect these links
and do not close the BCB before authorized to do so by the service engineer.
Note: When connecting the cables between battery terminals and BCB, the connection should begin from the
BCB terminal.
6. Replace the protective covers.
After connection, take appropriate measures to seal the cable entry holes.

3.2 Wiring Of Signal Cable

3.2.1 Overview

For on-site specific needs, the UPS needs auxiliary connection to realize battery system (including the external battery
switch) management, communicate with PC, provide alarm signal to external devices, realize remote EPO or provide
bypass back feed circuit breaker signal and parallel communication. These functions are realized through the
communication box in the UPS cabinet. As shown in Figure 3-5, the communication box provides the following ports:
User dry contact port
RS232 communication port
USB communication port
Parallel communication port
LBS communication port
RS485 communication port
Intellislot port
Connection of split bypass
Connection of system output
Connection of battery
Liebert NXC 30kVA And 40kVA UPS User Manual
Chapter 3 Electrical Installation
Warning
Note
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