5-9
PG 720 P Programming Device
C79000-G7076-C721-02
5.5
Replacing the Backup Battery
A backup battery (3.6 V lithium battery) powers the real-time clock even
after the PG 720 is switched off. In addition to the time of day, all the
information about the PG 720 (device configuration) is stored in RAM. If the
backup battery fails or is removed, all these data are lost.
The clock uses very little power and the lithium battery has a high capacity
so that the battery can provide backup power for the real-time clock for many
years and seldom needs to be replaced.
If the battery voltage is too low, the time of day and the device configuration
data in the RAM are lost.
In this case, you must replace the backup battery. The battery is located on
the drive mounting.
To change the battery, proceed as follows:
1. Switch off your PG 720 and remove the power cable and all the connecting
cables.
2. Open the unit as described in Section 5.1.
3. Now change the battery by removing the connector and releasing it from the
clip.
4. Push the new battery firmly into the clip.
5. Close the unit as described in Section 5.6.
Hard disk drive
Backup battery
Clip
Figure 5-6 Clip for Backup Battery
!
Caution
Risk of damage!
Only replace the lithium battery with an identical battery or with a type
recommended by the manufacturer (Order No.: W79084-E1003-B1).
Dispose of used batteries in keeping with local regulations.
After you have changed the battery, you must set the configuration data of
your unit again using the SETUP program (see Chapter 6).
Battery Power
Supply for
Real-Time Clock
and Configuration
Battery Voltage
too Low
Replacing the
Battery
Changing SETUP
PG 720 Expansions
