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Operation 73
UPS SYSTEM (Cont’d.)
Hardware
Shutdown
MMU D# At least one of the following alarm conditions is present: Inverter
Fault, Rectifier Fuse Blown, Reverse Power, Overload Shutdown,
logic power supply failure, or inverter output symmetry failure. The
UPS module is taken off-line and is shut down.
[Contact Liebert Global Services at once. Do not attempt to reset the
circuit breakers.]
Emergency Off SCC
MMU
D*, L, S The Emergency Module Off (or Emergency Power Off) switch has
been pressed, which caused the UPS system to shut down and
transfer the load to the bypass line (or all power to the critical load
has been shutdown).
[Determine the cause of the emergency condition and correct it if
possible. Contact Liebert Global Services if you require assistance.]
COOLING
Ambient Over-
Temperature
MMU R, S The intake air to the UPS module exceeds the specified maximum
temperature.
[This condition only causes an alarm, but should be corrected
immediately to prevent damage to equipment due to overheating.]
Blower Failed MMU S A fault in one or more of the blower motors has occurred. This
condition only causes an alarm, but if not promptly corrected it could
cause an equipment over-temperature condition that would shut
down the UPS module.
[Check the blowers for proper operation. Contact Liebert Global
Services if you require assistance.]
Equipment Over-
Temperature
MMU S Sensors on power semiconductor heatsinks detect temperatures
above the steady state limits for these components. The control logic
sets off the alarm but does not shut down the UPS module if the
condition lasts less than 10 minutes.
[Check the air intake, air exhaust, and filters. Reduce the load or
transfer it to bypass. Contact Liebert Global Services if the alarm
persists.]
Over-Temperature
Timeout
MMU D, F An Equipment Over-Temperature condition has persisted for more
than 10 minutes. The UPS module is taken off-line and is shut down.
[Check the air intake, air exhaust, and filters before attempting to
start-up the UPS.]
REMOTE MONITOR PANELS
(Refer also to SCC and Module Remote Monitor Indications and Other Alarms That Activate Summary Alarms in
3.1.5 - System Configuration Screens)
Load On UPS — R (SCC) The UPS is operating properly. No corrective action is necessary.
New Alarm — R (SCC)
R (MMU)
Another new alarm message has been registered on the UPS
system.
[Clear the new alarm condition, if possible.]
System Summary
Alarm
— R (SCC) One or more of the UPS system alarm messageshas been activated
or a control logic failure has been detected by a watchdog timer.
[Use the Present Status screen to determine which alarms are
active. Clear the new alarm condition if possible to do so.]
Module Summary
Alarm
— R (MMU) One or more of the UPS module alarm messages has been
activated.
[Use the Present Status screen to determine which alarms are
active. Clear the new alarm condition, if possible to do so.]
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