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Electrical Connections—UPS
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Split Bypass Connections
6. If a split bypass configuration is used, connect the AC input supply cables to the rectifier input
terminals (A1-B1-C1-N1) and the AC bypass supply cables to the bypass input terminals
(A2-B2-C2-N1) and tighten the connections to 240lb-in. (27N-m) (M10 Bolt). Ensure correct phase
rotation.
Output System Connections—Ensure Correct Phase Rotation
7. Connect the system output cables between the UPS output busbars (A-B-C-N terminals) and the
critical load and tighten the connections to 240lb-in. (27N-m) (M10 bolt).
Internal UPS Battery Connections
The UPS internal batteries will be connected at the factory, EXCEPT the connections between the
shelves and to the breaker.
Observe the battery cable polarity. Be sure that the battery connection is made with the cor-
rect polarity.
8. Refit all protective covers removed for cable installation.
3.3 Control Cables Details
3.3.1 Static Bypass Assembly 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).
Terminations for these functions are located at the front of the static bypass assembly. 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
®
interface
• Temperature detect interface
NOTE
For split bypass operation, ensure that the busbars between bypass and rectifier inputs are
removed. The neutral line of the bypass input must be connected to that of the rectifier input.
!
WARNING
Risk of electrical shock and arc flash. Can cause property damage, injury and death.
If the load equipment will not be ready to accept power when the commissioning engineer
arrives, ensure that the system output cables are safely isolated.
!
WARNING
Risk of electrical shock and arc flash. Can cause property damage, injury and death.
The DC bus is live when this internal battery connection is made. This connection is to be
performed ONLY by Liebert Services at startup.