Emerson Liebert NXL series Operation And Maintenance Manual page 88

Liebert NXL UPS
Event Message Event Definition
Maintenance
The external maintenance bypass
Bypass breaker indicates that it is in the open
Breaker(MBB) position.
Open
Man Rexfer
This summary event means the
Inhibit
conditions required to perform a manual
transfer to Inverter (online) are not met
(Inverter must be in sync with bypass).
This status message is self-clearing.
When the condition is no longer present,
the message and any control activity
tied to the status event reverts to
normal.
Manual Xfer
This summary event means the
Inhibit
conditions required to perform a manual
transfer to bypass are not met (Inverter
must be in sync with bypass).
This status message is self-clearing.
When the condition is no longer present,
the message and any control activity
tied to the status event reverts to
normal
Max Load Alarm
The user adjustable maximum load
Ph A
alarm threshold was exceeded. This is a
"notification only" type alarm, meaning
the UPS takes no action other than
sounding an audible alarm based on this
Max Load Alarm
setpoint. The setting allows the user to
Ph B
monitor the load status of the UPS.
For example, if the current load on
Phase A (or B, or C) is 50%, the user can
Max Load Alarm
set this setpoint to 80% and an alarm is
Ph C
received if the added load exceeds 80%.
The alarm may also be configured with
a delay, to prevent nuisance alarms due
to cycling loads.
The alarm is self-clearing. Once the load
level decreases to less than 95% of the
level setting, the alarm clears.
Liebert NXL alarm and status messages (continued)
Page 88
Operation and Maintenance Manual 250-300-400-800kVA
Recommended Action
The condition clears from the Active
Event Window when manual re-transfers
are enabled.
A possible reason for this condition is an
unstable generator. If the generator
frequency is not stable, or not at 50 Hz,
the Inverter may have difficulty
maintaining or acquiring synchronization
with the bypass source.
To check the synchronization of the
Inverter to bypass, click "Transfer" and
observe the synchroscope. A non-sync
condition is indicated by a varying phase
angle error, rather than a stable "0"
degree indication.
If the unit is not on generator, and the
bypass voltage otherwise appears normal,
contact your factory-authorized service
provider.
The condition clears from the Active
Event Window when manual transfers
are enabled.
A possible reason for this condition is an
unstable generator. If the generator
frequency is not stable, or not at 50 Hz,
the Inverter may have difficulty
maintaining synchronization with the
bypass source.
To check the synchronization of the
Inverter to bypass, click "Transfer" and
observe the synchroscope. A non-sync
condition is indicated by a varying phase
angle error, rather than a stable "0"
degree indication.
If the unit is not on generator, and the
bypass voltage otherwise appears normal,
contact your factory-authorized service
provider.
Press "SILENCE" to silence the audible
alarm.
Check the kW load % displayed for A (or
B, or C) phase.
To check the setpoint for the alarm, press
"Config," "User Settings," "Adjustable
Setpoints," "Max Load Alarm."
Compare the setpoint to the displayed
load percentage. If the load percentage
displayed is correct and the value exceeds
the setpoint, raise the setpoint to clear
the alarm, or reduce the load below the
setpoint.
Contact your factory-authorized service
provider.