Vertiv
™
|
Liebert
®
NX
™
225-600kVA Installation Manual | Rev. 8 | 07/2017
9
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
E
XTERNAL
P
ROTECTIVE
D
EVICES
For safety, it is necessary to install circuit breakers in the input AC supply and external battery system. 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
Figure 14
for overload capacity.
2.2
P
OWER
C
ABLES
The UPS requires both power and control cabling. All control cables, whether shielded or not, should be run
separately from the power cables in metal conduits or metal ducts that 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
Tables 9
through
12
, 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
).
When sizing battery cables, a maximum volt drop of 2VDC is permissible at the current ratings given in
Table 12
.
The following are guidelines only and are superseded by local regulations and codes of practice where
applicable:
•
The grounding conductor should be sized according to the fault rating, cable lengths, type of protection, etc. The
grounding cable connecting the UPS to the main ground system must follow the most direct route possible.
•
Consideration should be given to the use of paralleled smaller cables for heavy currents, as this can ease installation
considerably.
•
AC and DC cables must be run in conduits according to local codes, national codes and standard best practices. This will
prevent creation of excess EMI fields.
!
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.
