Liebert NX User Manual page 70

Operator Control Panel and Display
Table 22 UPS messages (continued)
Message
Unit Over load Timeout
Byp. Abnormal Shutdown
Inverter Over Current
Bypass Phase Reversed
Load Impact Transfer
Transfer Time-out
Load Sharing Fault
DC Bus Abnormal
System Transfer
Parallel Board Fault
DC Bus Over Voltage
Parallel Connect Fault
Bypass Over Current
LBS Active
Setting Save Error
Mains Neutral Lost
Protocol version clash
Battery ground fault
Inv. Turned On Manually
Inv. Turned Off Manually
EPO
Transfer Confirm
Transfer Cancel
Unit Off Confirm
System Off Confirm
Description / Suggested Action (if any)
The UPS is confirmed to overload and the overload times out.
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.
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).
Both bypass and inverter voltages unavailable. Load interruption
Inverter Pulse Width Modulation module overloaded.
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
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.
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.
UPS modules within a parallel system are not sharing the load current equally.
DC input voltage to inverter beyond limits. Inverter shuts down. Load transfers to bypass.
The whole paralleled UPS system transferred to bypass at the same time. This message will
appear on the UPS which passive transfer to bypass
Malfunction of the paralleling control circuits of this UPS module. Can cause "System Transfer"
to bypass.
Rectifier, inverter and battery converter were shutdown because DC bus voltage is too high.
Check whether there is a fault in rectifier side. If no, then check whether overload occurs.
Restart the inverter after resetting the fault
The parallel cables are not connected correctly in a parallel system.
Reset the fault by pressing the "fault clear" button, then restart the inverter by pressing the
"inverter on" button.
Bypass current is over limit above 135% rating. The UPS just alarms and does nothing.
Load Bus Synchronisation is active. The UPS is acting as an LBS master or slave in a dual bus
configuration.
History records not saved. (Reserved)
AC Input mains reference neutral not detected.
Firmware incompatibility between Monitor Board and Digital Signal Processor Board.
Battery leakage to ground detected (option)
Manual Turn On via front panel
Manual Turn Off via front panel
Emergency Power Off direct access key pressed or external command received
Prompt to press "enter" key to acknowledge that an interrupted load transfer to bypass will
happen.
Prompt to press "ESC" key to avoid that an interrupted load transfer to bypass will happen.
Prompt to press "enter" key to acknowledge that the UPS will be disconnected from other
paralleled UPS modules.
Prompt to press "enter" key to acknowledge that the all paralleled UPS will be disconnected
from the load.
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