Emerson UPS Systems installation manual Recommended lug sizes

Specifications

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These are guidelines only and are superseded by local regulations and codes of practice where appli- cable.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.

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