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Operation 71
BYPASS (Cont’d.)
Auto Transfer to
Bypass
SCC D, E, F The critical load has been automatically transferred to the bypass
line.
[Use the History Status screen to determine the cause for the
transfer. Clear all of the alarms before attempting to retransfer the
load from bypass to UPS.]
Auto Retransfer
Primed
SCC — An automatic retransfer will be initiated when the OK to Transfer
condition has been present for 10 seconds, if the overload has
dropped below 100% of the rated SCC current and if enough UPS
modules are on-line.
Manual Reset/
Retransfer
SCC — A manual retransfer is required. Either a system overload condition
has lasted more than 5 minutes, or no more auto-retransfer attempts
are available. Note that this alarm is only used if auto-retransfer
attempts are enabled.
[Perform a manual retransfer if all necessary conditions are present.]
Static Switch
Unable
SCC S The UPS output is not synchronized to the bypass power source.
The static bypass switch is disconnected, or it has failed internally.
[Emergency and overload transfer to the bypass source is not
available. Manually set the Static Switch Disconnects to ON (closed)
if the static switch is disconnected. If the alarm conditions are
automatically corrected, reset the alarm to clear it. Contact Liebert
Global Services if the alarm stays on.]
Bypass Not
Available
SCC — The bypass power source voltage is not within specifications.
[Check the bypass power source.]
Bypass Phase
Sequence Wrong
SCC — The power conductors on the bypass line are not wired to the UPS in
the required sequence. This alarm should appear only during initial
start-up or after a repair to the source power system.
[Disconnect power from the bypass line and correct the wiring. A
Liebert Global Services representative must be present during initial
start-up of your UPS System.]
UPS SYSTEM
Input Current
Unbalanced
MMU E At least one input phase differs from the average current by 10% or
more for four (4) hours. Contact Liebert Global Services. If the
condition persists, transfer the load to the bypass line.
Control Power
Fail
SCC
MMU
L, S
L, R, S
The logic control power supply from the UPS output is not operating
properly. The UPS module continues operating but will shut down if
the input power fails. The SCC continues operating but will shut
down if the bypass power fails. Contact Liebert Global Services
immediately.
Output Over/
Under Frequency
SCC L, S Output frequency differs from the nominal (60 Hz) by more than 0.5
Hz. No transfer or shutdown occurs.
[Contact Liebert Global Services at once.]
Output Under-
Voltage
SCC D, F, L, S The UPS system 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.]
Output Over-
Voltage
SCC D, F, L, S The UPS system output voltage is above the maximum (+10%)
deviation from nominal. The load automatically transfers to the
bypass line. All UPS modules are taken off-line and are shut down.
[Contact Liebert Global Services at once. Do not attempt to reset
circuit breakers.]
Table 1 Alarm Messages - Meaning and Corrective Action (continued)
Alarm
Message
Cabinet
Location
Special
Functions
Meaning and
Corrective Action in Brackets [ ]
Table 1 Abbreviations
D = auto-dial; L = latches
E = reports only; R = remote
F = freezes; S = summary
D* = auto-dial initiated by Auto Transfer to Bypass if load is on UPS when alarm occurs
D# = auto-dial initiated through Module N (1-6) off-line