Single-Module Mechanical Installation
4
1.6 Power Cables
The Maintenance Bypass Cabinet requires both power and control cabling once it has been mechani-
cally installed. All control cables must be separate from the power cables. Run control cables in metal
conduits or metal ducts that are electrically bonded to the cabinets they are connected to.
The cable design must comply with the voltages and currents provided in Tables 7 and 8, follow local
wiring practices and take into consideration the environmental conditions (temperature and physical
support media).
For cable entry terminal, refer to Figure 9.
The following are guidelines only and superseded by local regulations and codes of practice where
applicable:
• Take special care when determining the size of the neutral cable (grounded conductor), because
current circulating on the neutral cable may be greater than nominal current in the case of non-
linear loads. Refer to Tables 7 and 8.
• The grounding conductor should be sized according to the fault rating, cable lengths, type of pro-
tection, etc. The grounding cable connecting the UPS to the main ground system must follow the
most direct route possible.
• Consider using smaller, paralleled cables for heavy currents as a way of easing installation.
Figure 1 Cabinet arrangement—Liebert NXL UPS, battery cabinets, maintenance bypass cabinet
!
WARNING
Before cabling up the cabinet, ensure that you are aware of the location and operation of the
external isolators that connect the input/bypass supply.
Check that these supplies are electrically isolated, and post any necessary warning signs to
prevent their inadvertent operation.
Note: If a maintenance bypass
cabinet is used, it must be
installed on the right side of
the Liebert NXL UPS
Liebert
NXL
UPS
Liebert
NXL
UPS
Maintenance
Bypass
Cabinet
Battery
Cabinet
Liebert
NXL
UPS
Maintenance
Bypass
Cabinet
Additional
Battery
Cabinet(s)
Battery
Cabinet
Liebert
NXL
UPS
Additional
Battery
Cabinet(s)
Battery
Cabinet
Liebert
NXL
UPS
Additional
Battery
Cabinet(s)
