Load Transfer-1+N System: Add A Ups To The System (Collective) - Emerson Liebert NXL 250 kVA Operation And Maintenance Manual

2.15.9 Load Transfer—1+N System: Add a UPS to the System (Collective)
This section lists typical step-by-step instructions. The touchscreen will list all steps required for the
process, based on the unit's condition and other factors.
1. Provide power to all the UPS controls to permit the display touchscreen and system logic to
function properly.
a. Close the Bypass Input Breaker (BIB). This breaker is external to the UPS, possibly in the
Maintenance Bypass Cabinet. The display touchscreen should startup.
b. Close the Rectifier Feed Breaker (RFB). This breaker is external to the UPS, possibly in the
Maintenance Bypass Cabinet
c. Bypass Circuit Breaker (BFB)—This circuit breaker should be open (see Figures 2 and 6 for
the location).
d. Optional Module Output Breaker (MOB)—This circuit breaker should be open. This breaker
is external to UPS, possibly in the paralleling gear.
2. Start the UPS and put the Inverter in Standby Mode.
a. Close the MOB breaker associated with this module.
b. Press "Start-up," then "Manual Start," then "This Module" menu buttons (see Figure 38).
The "Close BFB" message will appear in the multipurpose window.
c. Close the BFB breaker (see Figures 2 and 6). The "Close CB1" message will appear.
d. Close CB1 (see Figures 2 and 6). This message will appear: "Press OK to Issue Rectifier On
Command."
e. Press "OK." This will start the UPS' rectifier. The message "Press OK to Issue Inverter On
Command" will appear.
f. Press "OK." The rectifier will be On and the Inverter will be on standby. The message "Press
OK to Issue MBD Enable Command" will appear.
g. Press "OK."
h. Close all Battery/DC breakers associated with this module. The UPS will stay in this mode
until all breakers are closed.
NOTE
Skip this command if the DC sources are not ready to be started. The DC breakers can be closed
individually from the startup command later (see 2.5 - Startup Menu).
This message will appear: "'This Module Startup' is complete. Proceed to Transfer menu to
connect this Inverter."
3. Press "Exit."
4. Under the Transfer menu on the touchscreen, press the "This Module" button. The
Transfer/Retransfer screen will appear in the multipurpose window (see Figure 41.
5. Press the "Connect Inverter" button. This will close CB2.
NOTE
If the UPS is not synchronized with the other units in the system, then the "Connect Inverter"
will be disabled.
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Liebert NXL 42
Operation