Yaskawa Σ-7 (Sigma-7) SERVOPACK troubleshooting
The Σ-7 (Sigma-7) SERVOPACK is Yaskawa’s servo amplifier family for SGM7 rotary, linear and direct-drive motors. Alarms show on the panel display as A. followed by three characters (for example A.C90); warnings use the A.9xx range. Each alarm has a fixed stopping method (Gr.1 or Gr.2) and is either resettable or not, so the first step is to read the code and the alarm history.
Diagnose this with AI
Try Free Servo Diagnostic Upload a photo of the alarm screen, the fault history or a data export. InduQT compares the evidence and suggests the next useful checks.
How it reports faults
- The alarm number appears on the SERVOPACK panel display. If an error occurs and no alarm number is shown, Yaskawa treats it as a SERVOPACK system error: replace the SERVOPACK.
- The list of alarms gives each alarm’s stopping method (Gr.1 or Gr.2) and whether it can be reset. “No” alarms cannot be cleared with an alarm reset; the cause must be removed and power cycled or the encoder set up again.
- Alarms are kept in the alarm history (Fn000 on the Digital Operator or SigmaWin+). A.E50, A.E60 and the FL-1 to FL-7 system alarms are only shown on the panel and are not stored.
- Warnings (A.900 to A.9xx) come before the matching alarm: A.900 before A.d00, A.910 before A.710/A.720, A.930 for a low absolute-encoder battery when Pn008 is set to warn.
Fault codes
| Code | Name |
|---|---|
| A.C90 | Encoder Communications Error |
| A.710 | Instantaneous Overload |
| A.720 | Continuous Overload |
| A.810 | Encoder Backup Alarm |
| A.d00 | Position Deviation Overflow |
| A.100 | Overcurrent Detected |
| A.400 | Overvoltage |
| A.020 | Parameter Checksum Error |
| A.040 | Parameter Setting Error |
| A.050 | Combination Error (SERVOPACK and motor capacities do not match) |
| A.101 | Motor Overcurrent Detected |
| A.300 | Regeneration Error |
| A.320 | Regenerative Overload |
| A.330 | Main Circuit Power Supply Wiring Error |
| A.410 | Undervoltage |
| A.510 | Overspeed |
| A.520 | Vibration Alarm |
| A.730 | Dynamic Brake Overload |
| A.7Ab | SERVOPACK Built-in Fan Stopped |
| A.820 | Encoder Checksum Alarm |
| A.830 | Encoder Battery Alarm |
| A.840 | Encoder Data Alarm |
| A.850 | Encoder Overspeed |
| A.860 | Encoder Overheated |
| A.b33 | Current Detection Error 3 |
| A.C10 | Servomotor Out of Control |
| A.C80 | Encoder Clear Error or Multiturn Limit Setting Error |
| A.C91 | Encoder Communications Position Data Acceleration Rate Error |
| A.C92 | Encoder Communications Timer Error |
| A.CC0 | Multiturn Limit Disagreement |
| A.d01 | Position Deviation Overflow Alarm at Servo ON |
| A.E60 | Reception Error in MECHATROLINK Communications |
| A.F10 | Power Supply Line Open Phase |
| A.910 | Overload (warning before A.710/A.720) |
| A.930 | Absolute Encoder Battery Error (warning) |
Evidence to collect
- Photo of the panel display with the alarm code
- Alarm history (Fn000) export from SigmaWin+
- SERVOPACK and motor model numbers from the nameplates
- What the axis was doing: power-up, servo ON, accelerating, constant speed, decelerating or stopped
- Settings of Pn100–Pn103 and Pn520 if tuning or deviation is involved
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