8488

Category: Alarm

Cause

1. Incorrect main circuit cable wiring or poor contact
2. Internal main circuit cable short circuit or ground fault
3. Internal servo motor short circuit or short circuit to ground
4. Internal servo unit short circuit or ground fault
5. Incorrect regenerative resistor wiring or poor contact
6. Frequent use of the dynamic brake (emergency stop caused by DB or the servo unit), or a DB overload alarm occurred
7. The regenerative resistance is too high and exceeds regenerative processing capacity
8. The servo unit regenerative resistance is too low
9. A high load is applied while the servo motor is stopped or running at low speed
10. Malfunction caused by noise
11. Servo unit fault

Corrective action

1. Confirm whether the wiring is correct and correct the wiring.
2. Check for short circuits between cable UVW phases or between UVW and ground. Replace the cable if short-circuited.
3. Check for short circuits between motor terminal UVW phases or between UVW and ground. The servo motor may be faulty. Replace the servo motor.
4. Check for short circuits between UVW phases of the servo unit motor connection terminals or between UVW and ground. The servo unit may be faulty. Replace the servo unit.
5. Confirm whether the wiring is correct; correct it if incorrect
6. Use DB resistor power consumption (Un00B) to check DB usage frequency. Alternatively, use the alarm history display (Fn000) to check whether DB overload alarms A.730,A.731 occurred. Change the servo unit selection, operating method, and mechanism to reduce DB usage frequency. 7. Use the regenerative load ratio (Un00A) to check regenerative resistor usage frequency; reconsider the regenerative resistance based on operating conditions and load. 8. Use the regenerative load ratio (Un00A) to check regenerative resistor usage frequency; change the regenerative resistance to a value at or above the minimum permissible servo unit resistance.
7. Confirm whether operating conditions are outside the servo drive specifications. Reduce the load applied to the servo motor or operate at a higher speed.
8. Improve noise conditions relating to wiring, installation, etc. and check the effect. Take noise prevention measures, such as correct FG wiring. Use the same FG wire size as the Servo unit main circuit wire size.
9. Turn on the power again. If the alarm persists, the servo unit may be faulty. Replace the servo unit.