Справочник Пользователя для Emerson UPS Systems

This section describes the requirements that must be taken into account when planning the position-

ing and cabling of the Liebert NXL Maintenance Bypass Cabinet.
This chapter is a guide to general procedures and practices that should be observed by the installing 

engineer. The particular conditions of each site will determine the applicability of such procedures.

Three-phase input supply required.
The standard Liebert NXL UPS is suitable for connection to three-phase, four-wire (+ Earth) 

TN-C, TN-S, IT-G, IT-IG or three-phase, three-wire plus ground, IT-UG.
If using the Liebert NXL UPS with an IT Power system, a four-pole disconnect device must be 

included as part of building installation.

Before installing the Maintenance Bypass Cabinet, carry out the following preliminary checks:

• Visually examine the equipment for transit damage, both internally and externally. Report any 

damage to the shipper immediately.

• Verify that the correct equipment is being installed. The equipment supplied has an identification 

tag on the back of the main door reporting: the type, size and main calibration parameters of the 

UPS.

• Verify that the room satisfies the environmental conditions stipulated in the equipment specifica-

tions, paying particular attention to the ambient temperature and air exchange system.

The Maintenance Bypass Cabinet is intended for indoor installation and should be located in a cool, 

dry, clean-air environment with adequate ventilation to keep the ambient temperature within the 

specified operating range (see 3.0 - Specifications).
All models of the Liebert NXL Maintenance Bypass Cabinet are convection-cooled. To permit air to 

enter and exit and prevent overheating or malfunctioning, do not cover the ventilation openings.
When bottom entry is used, the conduit plate can be removed and punched and replaced. The bottom 

conduit plate must be replaced for proper airflow. If necessary to cool the room, install a system of 

room extractor fans.

Do not apply electrical power to the UPS equipment before the arrival of the commissioning 

engineer.

The Maintenance Bypass Cabinet should be installed by a qualified engineer in accordance 

with the information contained in this chapter and all equipment not referred to this manual 

is shipped with details of its own mechanical and electrical installation.

Eye protection should be worn to prevent injury from accidental electrical arcs. Remove rings, 

watches and all metal objects. Only use tools with insulated handles. Wear rubber gloves.

NOTE
The Maintenance Bypass Cabinet is suitable for mounting on concrete or other non-