Fuji Electric ALPHA7, User Manual

Page: 426 / 662

CHAPTER 7 MAINTENANCE AND INSPECTION
Troubleshooting Method
7-19
7
19. Encoder Overheat
[Display] [Description of detected alarm]
AL.EH -
The encoder inside the servomotor may be overheated.
[Cause and remedy]
Cause Remedy
Excessive ambient temperature

Reduce the ambient temperature of the servomotor to
40 [°C] or lower.

Remove shields interrupting heat radiation, if there
are any.
The effective torque exceeds the
rating.

Increase the cycle time and reduce the operation
frequency.
The main body of the encoder detects this alarm according to results of self-diagnosis.
20. Absolute Data Lost
[Display] [Description of detected alarm]
AL.dL1
AL.dL2
AL.dL3
The absolute data of the encoder is lost.

dL1: Battery voltage drop, broken encoder cable, loss of
multi-rotation data

dL2: Multi-turn data fault in encoder

dL3: Detection at power-on after an ET alarm
[Cause and remedy]
Cause Remedy
dL1 alarm

Replace the battery and preset the position.
If it still can not be solved, please check if the
encoder cable is not broken and correct.

A warning is displayed at the keypad if the battery
voltage is low. (If PA2_78 is set at 1)
dL2 alarm

Perform position preset. If the alarm persists, replace
the servomotor.
dL3 alarm

After position preset, dL3 is canceled but the ET
alarm persists.

If the ET alarm is not canceled, replace the
servomotor.
For details, refer to "CHAPTER 11 ABSOLUTE POSITION SYSTEM."