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Wiring Connections
26
8.0 WIRING CONNECTIONS
8.1 Specific Connections
Refer to the drawings in this manual and any other drawings provided by Liebert for this installation.
Make all of the following connections:
1. AC power cables from input power source circuit breaker (RIB) to each UPS Module Input.
Observe phase rotation.
2. AC power cables from bypass power source circuit breaker (BIB) to UPS system bypass input at
System Control Cabinet (SCC). Observe phase rotation.
3. AC power cables from each UPS module output to SCC or to switchgear for critical load bus.
Observe phase rotation.
4. Each UPS module must have its output neutral connected to the SCC for parallel operation. A
minimum of a parity-sized neutral wire is recommended on this circuit for optimum system
performance, regardless of the load configuration.
5. AC power cables from UPS System Control Cabinet (SCC) Output to critical load or maintenance
bypass panelboard or switchgear. Observe phase rotation.
!
WARNING
Verify that all incoming high and low voltage power circuits are de-energized and locked out
before installing cables or making electrical connections.
All power connections must be completed by a licensed electrician experienced in wiring UPS
equipment and in accordance with all applicable national and local electrical codes.
Improper wiring may cause damage to the UPS or injury to personnel.
!
CAUTION
All shielded cables, non-shielded cables, non-shielded control wires, non-shielded battery
breaker control wires and non-shielded remote control wires must be housed in individual,
separate, steel conduits. Placing multiple cables in the same conduit with other control or
power wiring may cause system failure.
NOTE
Use appropriately sized wire as a grounding conductor. Solid metal conduit is not a suitable
ground conductor for UPS systems and could negatively affect system performance.
!
CAUTION
If there are line-to-neutral loads connected to the UPS output, the bypass input source must
be wye connected and have three phases plus neutral plus ground. If the specified input is not
available, an isolation transformer is required. Refer to 6.1 - Preferred Grounding
Configuration, Wye-Connected Service, 6.3 - Preferred Grounding Configuration
With Isolated Bypass and 6.4 - Alternate Grounding Configuration, Non-Isolated.
See 6.0 - Configuring Your Neutral and Ground Connections for an explanation of
proper grounding techniques.
NOTE
If your installation includes a Maintenance Bypass Panelboard or switchgear, some or all
power cables will be terminated in that equipment. Make sure all required wiring between the
UPS system and this switchgear is completed per the submittal drawings. Observe phase
rotation.