Liebert 1000kVA manual Alarm messages meaning and corrective action

Operation

Table 9	Alarm messages - meaning and corrective action
Alarm			Cabinet	Special
Message			Location	Functions	Meaning and Corrective Action
AC INPUT
					The rectifier input line voltage is outside of specified limits or the input
					circuit breaker is opened while the battery circuit breaker remains closed.
Input Fail			MMU	—	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
					Either the positive (+) or negative (-) DC bus is grounded. No transfer or
DC Ground Fault			MMU	D, L, S	shutdown occurs.
					Contact Liebert Global Services at once. Do not attempt to locate or repair
					the fault.
					At least one DC capacitor fuse has opened. The UPS module is taken off-
DC Capacitor			MMU	D, F, S	line and the input and battery circuit breakers trip open.
Fuse Blown					Contact Liebert Global Services at once. Do not attempt to reset the
					circuit breakers.
					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
Battery CB Open			MMU	D, R, S	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.
					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
Battery			MMU	D, R, S	of auxiliary power is restored to the UPS module, the UPS automatically
Discharging					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.
					The battery voltage is approaching the minimum discharge voltage
Low Battery			MMU	D, R, S	(approximately 5 minutes remaining).
Warning					Complete the controlled shutdown of the critical load. Reset the alarms if
					the input power is restored before shutdown.
					The battery voltage has decreased to the minimum discharge value. The
Low Battery					UPS module is taken off-line (no power to the critical load) and the
			MMU	D, F, L, S	battery and input circuit breakers trip open.
Shutdown
					Perform a UPS system start-up procedure when AC power becomes
					available.
					The maximum preset value of the DC Bus voltage has been exceeded.
DC Overvoltage					The UPS module is taken off-line and the input and battery circuit
			MMU	D, F, L, S	breakers trip open.
Shutdown
					Contact Liebert Global Services at once. A fault may have occurred within
					the UPS. Do not attempt to reset the circuit breaker.
BYPASS
					The critical load is being supplied power from the bypass line and is
Load On Bypass			SCC	D	therefore exposed to utility power disturbances.
					Clear all of the alarms before attempting to retransfer the load from the
					bypass line to the UPS.
Table 9 Abbreviations
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

D# = auto-dial initiated through Module N (1-6) off-line

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