Fuji Electric ALPHA7, User Manual

Page: 420 / 662

CHAPTER 7 MAINTENANCE AND INSPECTION
Troubleshooting Method
7-13
7
10. Overload
[Display] [Description of detected alarm]
AL.oL1
AL.oL2

OL1: Instantaneous alarm such as a locked shaft.

OL2: The effective torque exceeds the allowable limit of the
servomotor. (Detection at electronic thermal relay built in servo
amplifier)

Overload level: See "9.2 Overload Characteristics".
[Cause and remedy]
Cause Remedy
The servomotor fails to rotate
mechanically.

Check if the brake is active.
The mechanical system is too heavy
against the servomotor capacity.

Examine the servomotor capacity, based on
the load factor.

If the rotation speed can be reduced, add a
reduction gear.

Apply the brake to retain a stopped
elevator.
The acceleration/deceleration frequency
and operation frequency are too high. 
Increase the cycle time and decrease the
operation frequency.
Servo amplifier is damaged.

Replace the servo amplifier.
If an OL2 alarm is caused but no damaged servo amplifier or incorrect wiring is found, the
servomotor capacity must be examined.
Check the OL thermal value with the PC Loader or monitor mode of the keypad in both cases.