Siemens YASKAWA 840DI Maintenance Manual page 42

2.4 Check of battery
INFO
• Only qualified personnel may perform replacing battery for absolute encoder.
Otherwise an electric shock, a malfunction, an injury or a damage of equipment could result.
• Before replacing the battery for absolute encoder, confirm that the main circuit power supply is
switched off and the control power supply is switched on.
Position value in absolute encoder could be lost if work is executed with control power supply OFF.
• Don't touch terminals on Converter or connector of battery.
Otherwise, electrical device could be destroyed by electrostatic discharge.
Criteria of replacing battery
If the voltage of the absolute encoder battery decreases to 2.7V or less, the Servo Unit issues
a Battery warning (A.93)" and following message is displayed on Operator panel of CNC.
"
380500 Profibus-DP: fault on drive %1, code 147, value %3, time %4"
"
%1" is substituted by an axis name.
"
• Estimated time for position data loss after warning is 2 weeks a motor encoder under the
conditions with 20 degree temperature and without control power supply. But it may change
depending on operating status.
• If position value is lost by battery exhaustion, Servo Unit issue "encoder backup alarm (A.81)
and CNC display
"380500 Profibus-DP: fault on drive %1, code 129, value %3, time %4
on operator panel. Only reset for absolute encoder can remove above alarm. In this case, machine
zero point must be referenced again after replacing battery. Please refer to the document published
by machine tool builder.
Replacing battery
Backup battery for absolute encoder is equipped in Converter.
Replace the battery by following procedure.
1. Turn on control power supply and turn off main circuit power supply.
2. Take out 2-M4 screws for battery cover and remove battery cover.
3. Pull out battery connector (CN8).
4. Remove battery from the battery cover.
5. Mount new battery on the battery cover.
6. Insert battery connector of new battery. (CN8)
7. Mount the battery cover on Converter and fixed it by 2-M4 screws.
WARNING
CAUTION
2-14
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