Control Cables; Monitor Board Features; Figure 5 Monitor Board U2 - Emerson Liebert NX 480V User Manual

Frequency Converter Mode
If a frequency converter configuration is used, connect the AC input supply cables to the rectifier
input busbars (A-B-C terminals). Torque to 88 lb-in (10N-m) for M8 bolts. Ensure correct phase rota-
tion. There will not be any AC bypass supply cables to the bypass input (A-B-C terminals) and tighten
the connections.
NOTE
The operations described in this section must be performed by authorized electricians or
qualified technical personnel. If any difficulties arise, contact Liebert at 1-800-LIEBERT.
NOTE
For frequency converter operation, ensure that the linking busbars between the bypass and the
rectifier input are removed.
2.2

Control Cables

2.2.1

Monitor Board Features

Based on your site's specific needs, the UPS may require auxiliary connections to manage the battery
system (external battery circuit breaker, battery temperature sensor), communicate with a personal
computer or provide alarm signaling to external devices or for Remote Emergency Power Off (REPO).
The monitor board, arranged for this purpose, is located on the rear of the operator access door. The
main features are:
• Input and Output dry contacts signal (one pair of contacts of relay)
• Emergency Power Off control (EPO)
• Environmental parameter input interface
• User communication (for data setting and user background monitor)
• Liebert IntelliSlot
• Modem interface
• Temperature detect interface
Figure 5 shows the relationship and connection between the monitoring (U2) board and other boards
in the UPS.
Figure 5 Monitor board U2
Auxiliary Power
®
interface
U1
DSP Control
M5
Monitor Board
User Interface
K1
Key & LED Board
U2
Parallel Logic
X1
Board
15
Electrical Connections
M3
Board