User manual

Operating Instructions
73
9.0 OPERATING INSTRUCTIONS
9.1 NX Operating Modes
The NX can operate in any of four modes, as shown in Table 23. This section provides instructions on
switching between modes, resetting the UPS, switching the inverter On and Off and performing other
operations.
Table 23 UPS operating modes
Operating
Mode
Rotary Switch
Position Description
Normal
Operation
NORMAL The UPS is powering the load.
On Maintenance
Bypass
MAINT The UPS is shut down but the load is connected to utility power via the
Maintenance Bypass Supply line.
NOTE: The load is not protected against disturbances in AC input power in this
mode.
On Test
TEST No load power is supplied by the UPS. The load is connected to utility power
via the Maintenance Bypass Supply line.
NOTE: The load is not protected against disturbances in AC input power in this
mode.
On Static
Bypass
BYPASS
or
NORMAL
The load power is supplied through the static bypass line. This may be
considered as a temporary mode during load transfers between inverter and
maintenance bypass or supply under abnormal operating conditions.
NOTE
1. The user controls and indicators mentioned in these procedures are identified in 8.0 -
Operator Control and Display Panel.
2. The audible alarm may sound at various points during these procedures. It can be canceled
at any time by pressing the SILENCE ON/OFF push button.
NOTE
This unit refers to some modes and conditions that are set or adjusted using proprietary service
software. To take advantage of all the available features for the NX, the unit must be
commissioned by a Liebert factory-trained service engineer.