Liebert NX is a mid-sized, three-phase uninterruptible power supply (UPS) system that delivers complete, centralized data center power protection. Emerson 10-30KVA User Manual. Download 3.14 Mb. For Business-Critical Continuity. The Liebert NX™ UPS is designed primarily for telecommunications and data processing applications. Liebert Corporation neither recommends nor knowingly sells this product for use with life support and other designated “critical” devices.
UPS Status Messages
99
Inverter Contactor Fail
The Inverter contactor has failed.
This alarm is triggered when the feedback signal and the state of the contactor is not identical for
a specified time. Contact Liebert Global Services at 800-543-2378 for assistance.
Output Fuse Fail
At least one of the output fuses is open. Contact Liebert Global Services at 800-543-2378 for
assistance.
Control Power 2 Fail
Control Power 2 is abnormal or lost. Contact Liebert Global Services at 800-543-2378 for
assistance.
Unit Overload
The UPS is confirmed to be overload when the load arises above 105% nominal rating.
The alarm automatically resets once the overload condition is removed.
1. Confirm that the alarm is true by checking the load percent indicated on the LCD panel to
determine which phase is being overloaded.
2. If the alarm is true, measure the actual output current to verify that the indications are valid.
Disconnect unnecessary load and ensure the safety. In a parallel system, a severe load
sharing error can also leads to the alarm.
Contact Liebert Global Services at 800-543-2378 for assistance.
System Overload
The UPS parallel system is confirmed to overload when the total load arises above 105% nominal
rating for the set basic number of UPSs. The alarm automatically resets once the overload
condition is removed.
1. Confirm that the alarm is true by checking the system load percent indicated on the LCD
panel to determine which phase is being overloaded.
2. If the alarm is true, measure the actual output current to verify that the indications are valid.
Disconnect unnecessary load and ensure the safety. In a parallel system, a severe load
sharing error can also leads to the alarm.
Unit Overload Timeout
The UPS is confirmed to overload and the overload times out.
Liebert Nx Ups
Note 1: the highest loaded phase will indicate overload timing-out first.
Note 2: When the timer is active then alarm “unit overload” should also be active as the load is
above nominal.
Note 3: When the timer has expired, the inverter Static Switch is opened and the load transferred
to bypass. The inverter shutdown and will restart after 10 seconds.
Note 4: If the load decreases lower than 95% after 5 minutes, the system will transfer back to
inverter mode.
Liebert Nx 40kva Ups
Confirm that the alarm is genuine by checking the load percent indicated on the LCD. If an
overload is indicated then check the load, and investigate any additional load connected prior to
the alarm (if applicable).
Inverter Overcurrent
The current of inverter IGBT is over limit. If the fault will not reset, contact Liebert Global Services
at 800-543-2378 for assistance.
Bypass Phase Reversed
The phase sequence direction of bypass voltage is reversed.
Normally, the phase of phase B lags 120 degrees behind phase A, and the phase of phase C lags
120 degrees behind phase B.
Verify that the phase rotation of the bypass supply presented to the UPS is correct, and rectify it if
it is found to be in error. Contact Liebert Global Services at 800-543-2378 for assistance.
Load Impact Transfer
A transfer to bypass occurred due to a large step load. The UPS should recover automatically.
Turn on connected equipment in sequential order to reduce the step loading of the inverter.
Transfer Timeout
The load is on bypass power due to excessive number of transfers that occurred within the last
hour.
The UPS will recover automatically and will transfer the load back to inverter power within an
hour.
Load Sharing Fault
UPS working within a parallel system are not sharing load current correctly. Contact Liebert
Liebert Nx 20kva
Global Services at 800-543-2378 for assistance.
DC Bus Abnormal
Shut off inverter due to abnormal DC bus voltage.
Contact Liebert Global Services at 800-543-2378 for assistance.
System Transfer
The whole paralleled UPS system transferred to bypass at the same time. This message will
appear on the UPS which passive transfer to bypass.
Parallel Board Fault
Parallel board is not working correctly. Contact Liebert Global Services at 800-543-2378
for assistance.
Table 44
Liebert Nx 30 Kva Manual
UPS status messages (continued)
Event Message
Description / Suggested Action (if any)