Protective Devices; 3.2.10 Cabling Procedure - Emerson Liebert EXM User Manual

3.2.9

Protective Devices

For safety, it is necessary to install circuit breakers in the input AC supply external to the UPS
system. Given that every installation has its own characteristics, this section provides guidelines for
qualified installation engineers with knowledge of operating practices, regulatory standards and the
equipment to be installed.
UPS Rectifier and Bypass Input Supply
Protection from excessive overcurrents and short circuits in power supply input
External overcurrent protection for the AC output circuit is to be provided. See 8.3 - UPS
Electrical Characteristics and Table 28 for recommended breaker ratings.
Overcurrent protection for the battery circuit must be provided by the customer when using an
optional External Battery Cabinet.
• Dual Input Single Source
When wiring the UPS with dual inputs but with a single input source, the Rectifier input and the
Bypass input must be protected separately. Size the breakers according to the input currents
shown in Tables 23 and 24.
NOTE
For single or dual input, a 120V shunt trip coil(s) is required when a breaker is supplied by the
customer. See Figures 7 and 8 for details.
System Output
When using an external distribution panel for load distribution, the output neutral and input neutral
must be separated at the input to the UPS.

3.2.10 Cabling Procedure

WARNING
!
All operations described in this section must be performed by properly trained and qualified
electricians or technical personnel. If any difficulties are encountered, contact Emerson
Network Power. See the back page of this manual for contact information.
AVERTISSEMENT
!
Toutes les opérations décrites dans cette section ne doivent être effectuées que par des
électriciens ou des techniciens professionnels dûment formés et qualifiés . En cas de
difficultés, communiquez avec Emerson Network Power. Pour obtenir les renseignements de
contact, consultez la dernière page de ce manuel.
NOTE
Hydraulic pressure pliers, combinative tools and piston ring pliers should be used to connect
AC wiring.
Once the equipment has been positioned and secured for operation, and the battery and ground lugs
have been connected (see 3.2.6 - Cable Connections), connect the power cables as described below.
(Study the reference drawing in 4.0 - Installation Drawings.)
1. Verify that all incoming high and low voltage power circuits are de-energized and locked out or
tagged out before installing cables or making any electrical connections.
2. Remove the front I/O panel to gain easier access to the connections busbars.
3. Connect the facility ground and ancillary ground bus cables to the copper ground busbar located
in the middle of the Liebert eXM behind the output connections. All cabinets in the UPS system
must be connected to the user's ground connection.
NOTE
The grounding and neutral bonding arrangement must comply with the National Electrical
Code and all applicable local codes.
4. Identify and make power connections with incoming cables according to Steps 5 through 8.
25
Electrical Connections—UPS
®
Liebert eXM
™