1 IMPORTANT SAFETY INSTRUCTIONS
SAVE THESE INSTRUCTIONS
This manual contains important instructions that should be closely followed during installation and
maintenance of this Maintenance Bypass Cabinet.
This product is designed for commercial/industrial use only. This product is not intended for use with life
support and other designated “critical” devices. Maximum load must not exceed that shown on the UPS
and the Maintenance Bypass Cabinet rating label.
WARNING! Lethal voltages may be present within this unit even when it is apparently not
operating. Observe all cautions and warnings in this manual. Failure to do so may result in
serious injury or death. Never work alone.
The Liebert Maintenance Bypass Cabinet is designed for use on properly grounded (earthed)
208/240VAC, 60Hz supply, for installation by qualified personnel. This UPS equipment is intended to be
installed by a qualified / certified electrician who must review and approve customer supplied wiring,
circuit breakers, intended loads and verify correct input, output and grounded (earthed) connections to
ensure compliance with technical standards and national and local electrical codes. Installation
instructions and warning notices are located in the Installation section of this manual.
WARNING! To reduce the risk of fire:
The NMB1x and NMB4x models must be connected to a circuit provided with 100 amperes
maximum branch circuit overcurrent protection in accordance with applicable national and local
electrical codes.
The NMB5x and NMB8x models must be connected to a circuit provided with 125 amperes
maximum branch circuit overcurrent protection in accordance with applicable national and local
electrical codes.
Operate the UPS equipment in an indoor environment only in an ambient temperature range of 32°F to
104°F (0°C to 40°C). Install it in a clean environment, free from conductive contaminants, moisture,
flammable liquids, gases, or corrosive substances.
Never block or insert any object into the ventilation holes or other openings.
SYMBOL DESCRIPTION
Risk of Electrical Shock
Indicates Warning or Caution
Followed by Important Instructions
AC Input
AC Output
Table 1.1 Glossary of Symbols
Vertiv | Liebert® Maintenance Bypass Cabinet Installer/User Guide | 5
