Liebert Emerson NX UPS System - Manual (Page 54)

Operating Procedures
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6.2 UPS Startup
The NX must be fully installed and commissioned before startup, and external power isolators must
be closed. Once those general conditions are met, the UPS may be started.
6.2.1 Start-Up Procedure
To start the UPS from a fully powered-down condition:
1. Open the UPS door to gain access to the main power switches.
2. Close CB1.
3. Turn the rotary switch to TEST.
The bypass static SCR (M2) closes automatically and the LCD begins to show start-up screens.
The rectifier indicator flashes green while the rectifier is starting up. It stops flashing and
becomes solid green about 30 seconds after the rectifier enters the normal operation state. After
initialization, the bypass static switch closes.
Because output switch SW1-A is still open, the UPS channels power through Maintenance Bypass
Supply line (SW1-D). The bypass indicator extinguishes, provided that the bypass is normal.
The UPS mimic display indicators will be:
4. Turn the rotary switch to BYPASS.
The maintenance switch SW1-D opens and output switch SW1-A closes. The UPS powers from
static bypass instead of from maintenance bypass. The bypass and load indicators turn on. The
design of the rotary switch ensures uninterrupted output.
!
WARNING
During this procedure the output terminals will become live.
If any load equipment is connected to the UPS output terminals, please check with the load
user and ascertain whether it is safe to apply power to the load. If the load is not ready to
receive power, then ensure that it is safely isolated from the UPS output terminals.
!
CAUTION
Do not operate the rotary switch too fast. Always wait at least 30 seconds when rotating the
switch from one position to another
Indicator State
Rectifier indicator Off
Battery indicator Off
Bypass indicator Off
Inverter indicator Off
Load indicator Off
Status indicator Off
!
WARNING
Do NOT turn the rotary switch until the rectifier indicator stops flashing green.
Indicator State
Rectifier indicator Green
Battery indicator Off
Bypass indicator Green
Inverter indicator Off
Load indicator Green
Status indicator Amber