UPS Electrical Installation
6
2.0 UPS ELECTRICAL INSTALLATION
This chapter provides guidelines for qualified installers who must have knowledge of local wiring
practices pertaining to the equipment to be installed.
2.1 External Protective Devices
For safety, it is necessary to install circuit breakers in the input AC supply and external battery sys-
tem. Given that every installation has its own characteristics, this section provides guidelines for
qualified installation personnel with knowledge of operating practices, regulatory standards and the
equipment to be installed.
External overcurrent protection must be provided. See Table 6 - Liebert NXL UPS specifications
for overload capacity.
Dual Input
When wiring the UPS with a separate rectifier and bypass input, each input must be protected sepa-
rately. Size the breakers according to the input currents shown in Table 6.
2.2 Power Cables
The UPS requires both power and control cabling. All control cables, whether shielded or not, should
be run separate from the power cables in metal conduits or metal ducts which are electrically bonded
to the metalwork of the cabinets to which they are connected
The cable design must comply with the voltages and currents in Table 6, follow local wiring practices
and take into consideration the environmental conditions (temperature and physical support media),
room temperature and conditions of installation of the cable and system’s overload capacity (see 5.0 -
Specifications).
For cable entry terminal, refer to Figure 7.
NOTICE
For dual input operation ensure that any busbars between the bypass and the rectifier input
are removed.
When sizing battery cables, a maximum volt drop of 2VDC is permissible at the current ratings given
in Table 7.
!
WARNING
Risk of electrical shock. Can cause injury or death.
The UPS contains high DC as well as AC voltages. Check for voltage with both AC and DC
voltmeters before working within the UPS.
Only properly trained and qualified personnel wearing appropriate safety headgear, gloves,
shoes and glasses should be involved in installing the UPS or preparing the UPS for
installation.
!
WARNING
Risk of electrical shock. Can cause injury or death.
Before cabling the UPS, ensure that you are aware of the location and operation of the
external isolators that connect the UPS input/bypass supply to the power distribution panel.
Check that these supplies are electrically isolated, and post any necessary warning signs to
prevent their inadvertent operation.
