Specifications
29
Notes
See the Liebert NXL UPS installation manual, SL-25420, for UPS rectifier, UPS bypass and UPS out-
put sizes. The manual is available at the Liebert Web site: www.liebert.com
These are guidelines only and are superseded by local regulations and codes of practice where appli-
cable.
• Take special care when determining the size of the neutral cable, as current circulating on the
neutral cable may be greater than nominal current in the case of non-linear loads. Refer to the
values given in the Tables 7 and 8.
• The ground conductor should be sized according to the fault rating, cable lengths, type of protec-
tion, etc. The ground cable connecting the UPS to the main ground system must follow the most
direct route possible.
• Consideration should be given to the use of smaller, paralleled cables for heavy currents, as a way
to ease installation.
• In most installations, the load equipment is connected to a distribution network of individually
protected busbars fed by the maintenance bypass cabinet output rather than being connected
directly to the Maintenance bypass cabinet itself. Where this is the case, the maintenance bypass
cabinet output cables can be rated to suit the individual distribution network demands rather
than being fully load-rated.
• When laying the power cables, do not form coils to avoid increasing formation of electromagnetic
interference.
Table 15 Recommended lug sizes
Cable Size T&B Series 54000
Two Hole
#8 AWG 54850BE
#6 AWG 256-30695-868
#4 AWG 256-30695-733
#2-3 AWG 54811BE
#1 AWG 54857BE
#1/0 AWG 256-30695-593
#2/0 AWG 54862BE
#3/0 AWG 54864BE
#4/0 AWG 54866BE
250kcmil 54868BE
300kcmil 54870BE
350kcmil 54872BE
400kcmil 54874BE
500kcmil 54876BE
600kcmil 54878BE
750kcmil 54880BE
Use the T&B crimping tools recommended for these types of lugs.
