Filter
Top Products
Operation
51
Table 4 Alarm messages and corrective actions
Alarm
Message
Special
Functions Meaning and Corrective Action
AC INPUT
Input fail
The rectifier input line voltage is outside of specified limits or the input circuit breaker is
opened while the battery circuit breaker remains closed. The battery supplies power to the
critical load through the UPS inverter. Provide an alternate source of AC power or prepare to
initiate critical load procedures when battery reserve time is low.
DC BUS
DC Ground
Fault
D, L, S
Either the positive (+) or negative (-) DC bus is grounded. No transfer or shutdown occurs.
Contact Liebert Global Services (1-800-LIEBERT) at once. Do not attempt to locate or repair
the fault.
DC Capacitor
Fuse Blown
D, F, S
At least one DC capacitor fuse has opened. The UPS module is shut down and isolated.
Contact Liebert Global Services at once. Do not attempt to reset the circuit breakers.
Battery CB
Open
D, S
The module battery circuit breaker (MBD) is open. This circuit breaker can be opened either
manually or automatically in a UPS shutdown procedure. If the UPS is operating with this
breaker open, the critical load is not protected from loss of the utility source power.
After AC power is restored and the DC bus is at 100% operating voltage, manually close the
battery circuit breaker so the rectifier can charge the battery.
Battery
Discharging
D, R, S
The battery is discharging. This occurs whenever the battery supplies power to the load for
more than 5 seconds because of input power failure, a rectifier problem or an overload
condition. If the input power or a source of auxiliary power is restored to the UPS module,
the UPS automatically returns to normal operation. Watch the battery voltage carefully.
Reduce the load (begin controlled shutdown) to extend the battery back-up time. Reset the
UPS alarms after the input power is restored. The message clears after 30 seconds.
Low Battery
Warning
D, R, S
The battery voltage is approaching the minimum discharge voltage (approximately
5 minutes remaining). Complete the controlled shutdown of the critical load. Reset the
alarms if the input power is restored before shutdown.
Low Battery
Shutdown
D, F,
L, S
The battery voltage has decreased to the minimum discharge value. The UPS module shuts
down (no power to the critical load) and the battery and input circuit breakers trip open.
Perform a UPS system start-up procedure when AC power becomes available.
Battery Over
Temperature
(Optional)
D, S
The measured battery temperature exceeds the customer-defined limit for more than
1 minute. Alarm automatically clears when temperature falls below the limit for more than
1 minute. Determine the overtemperature cause.
Battery
Charge
Compensation
(Optional)
S
The UPS rectifier/charger is reducing the battery float voltage setpoint to compensate for
elevated battery temperature. The UPS automatically reverts to normal operation when
temperature returns below the limit.
DC
Overvoltage
Shutdown
D, F,
L, S
The maximum preset value of the DC Bus voltage has been exceeded. The UPS transfers
to bypass and the input and battery circuit breakers trip open. Contact Liebert Global
Services at once. A fault may have occurred within the UPS. Do not attempt to reset the
circuit breaker.
BYPASS
Load On
Bypass
D, R
The critical load is being supplied power from the bypass line and is therefore exposed to
utility power disturbances. Clear all of the alarms before attempting to retransfer the load
from the bypass line to the UPS.
Auto Transfer
to Bypass
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
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 load
Manual Reset/
Retransfer
A manual retransfer is required. Either an 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.
D = auto-dial L = latches
E = logs only R = remote
F = freezes S = summary
D* = auto-dial initiated by Auto Transfer to Bypass if load is on UPS when alarm occurs