Siemens RM400 C Series Operating Manual page 69

The date the BBU was first charged is noted in coded form on the yellow label on
the power supply. The month is indicated by letters from A through L, the year by its
last digit.
Starting up the BBU
Charging starts automatically as soon as the system unit is connected to the line
power supply. It takes about 36 hours to charge the batteries up completely.
If there is a power failure before the batteries are fully charged, the amount of power
that the BBU can supply depends on how long it has been charging for. The rule of
thumb is that five minutes of charging provides one second of backup power.
How the BBU works
If there is an extended loss of power, the BBU send a signal to the operating system,
which responds by performing a normal system shutdown. No power is supplied to
monitors while the line power is out.
Once the power failure is over and the line voltage has returned, the system is auto-
matically rebooted.
Correct functioning of the BBU is assured only if the battery fully charged.
The BBU can be expected not to function properly if the system unit is left discon-
nected from the power for an extended period (3 to 6 months). In such cases you
should always check the BBU.
Each time the battery is discharged, full operability is not restored until
i
the 36-hour charging period has elapsed.
If the system is in BBU (battery backup unit) operation, in emergencies
!
you can switch it off by turning the keylock switch to LOCAL and pressing
the [ON/OFF] button. This may cause loss of data.
U24802-J-Z146-2-7600 RM400 C Models
Installing peripherals
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