Operation
76
Inverter Ovld
xfer
Inverter
Overload
Transfer
Fault YES YES YES YES
With the load on UPS, at least one phase of
the UPS KVA or KW has exceeded the
rated KVA, KW, or RMS current vs. Time
equation. (Note: This fault would have been
preceded by an “Inverter Overload Phase x
alarm.) The UPS will transfer the load to
Static Bypass if it is available. If the fault or
overload clears the UPS will automatically
transfer from SBS to UPS. Remove the
excess load from the UPS and attempt to
re-start. If the load is below the rating of the
UPS and it will not re-start, contact Liebert
Global Services.
Inverter Fuse
Fail
Inverter Fuse
Fail Fault YES YES NO YES
One or more Output Fuses are open.
(because of capacitance in the system it
may take up to 1 minute after a fuse failure
to detect this fault). The system will transfer
the load to Static Bypass if available and
then shut down the UPS. Contact Liebert
Global Services Immediately.
Output Ov
xfer
Output
Overvolt
Transfer
Fault NO YES YES YES
The UPS module output voltage is above
the maximum (+10%) deviation from
nominal. The load automatically transfers to
the bypass line. The UPS module is shut
down and isolated. Contact Liebert Global
Services at once. Do not attempt to reset
circuit breakers.
Output Uv
xfer
Output
Undervolt
Transfer
Fault NO YES YES YES
The UPS module output voltage is under
the minimum (-12%) deviation from
nominal. The load automatically transfers to
the bypass line. If the alarm condition is no
longer present, reset the alarm and
retransfer the load from bypass to UPS.
Contact Liebert Global Services if alarm
persists.
SBS SCR
Open
SBS SCR
Open Fault YES YES NO YES
This fault can only be detected when the
load is on bypass. One or more of the Static
Bypass phases are open. The static switch
will be shut down and the UPS will shut
down. Power to the load will be lost.
Contact Liebert Global Services
Immediately.
SBS SCR
Shorted
SBS SCR
Shorted Fault YES YES NO YES
The system has detected a shorted SCR in
the Bypass line. If the unit is in the start-up
mode, start- up will be inhibited. If the unit is
on UPS, the unit will transfer to Bypass and
open the output contactor to prevent back
feed to the inverter from the Bypass line.
Contact Liebert Global Services
Immediately.
Table 7 Alarms, functions, and corrective actions (continued)
Actual
Alarm/fault
Name
Displayed
On Front
Panel
Description
of Alarm/
Fault
Fault
Or
Alarm
Latch
Mask
Dial
Mask
Freeze
Mask
Event Log
Mask Meaning and Corrective Action(s)