Operation
Liebert
®
NXL
™
50
2.15.17 1+N System Shutdown
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.
Perform a System Shutdown Procedure when you want to remove power from the entire UPS system.
Read all warnings in
before performing any maintenance on your Liebert NXL
UPS. These warnings and cautions must be observed during any work on the UPS.
Use the module Monitor/Mimic Display to determine the operating condition of the UPS module.
System Shutdown Procedure
1. On any module, press “Shutdown,” then press the “All Modules” menu button (see
).
This message will appear: “This system has no MBB. If shutdown is started, the load will no
longer be support by the UPS. Load drop may occur.”
2. Press “OK”. The Shutdown screen will appear in the multipurpose window (see
3. Press the “1+N” button. All modules in the system will transfer to Bypass.
4. If an external wrap-around bypass is not installed:
a. This message will appear: “UPS output will turn-off. Do you want to proceed?” Press “Yes” to
continue the shutdown.
b. All the UPS breakers—CB1, CB2, BFB and DC source—will open. The message “Open all
MOB’s” will appear.
c. Open all the MOB breakers to isolate the UPS units from each other
d. To isolate the system, open all the MOB breakers and utility feeds to the bypass and rectifier
inputs
5. If an external, wraparound bypass is installed:
a. If using a key interlock system, depress the key-release unit push button, turn the key and
remove it from the key-release unit.
b. If using a key interlock system, insert the key into the lock for the Maintenance Bypass
Breaker (MBB); retract the bolt.
c. Close the Maintenance Bypass Breaker (MBB).
d. Open the Maintenance Isolation Breaker (MIB). The UPS system is now isolated from the
critical load and the load is now on Maintenance Bypass.
e. If using a key interlock system, remove the key from the lock for the Maintenance Isolation
Breaker (MIB).
f. If the maintenance bypass cabinet or switchboard has an optional two-key interlock system,
reinsert the key into the solenoid.
g. All the UPS breakers—CB1, CB2, BFB and DC source—will open. The message “Open all
MOB’s” will appear.
h. Open all the MOB breakers to isolate the UPS units from each other
NOTE
Service and maintenance must be performed only by properly trained and qualified personnel
and in accordance with applicable regulations as well as with manufacturers’ specifications.
NOTE
The UPS system is now locked in bypass and cannot be transferred until the key is returned.
NOTE
Failure to close the Maintenance Bypass Breaker (MBB) will interrupt power to the load.
NOTE
The UPS units will shut down
Содержание Liebert NXL 250 kVA
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