Yaskawa GA500 fault GF: Ground Fault
Fault GF on a Yaskawa GA500 is Ground Fault: a current short to ground on the output side of the drive exceeded 50% of the drive rated current. Yaskawa lists damaged motor insulation, a motor cable shorted to ground, high leakage current from cable stray capacitance and drive hardware problems.
Diagnose this with AI
Try Free Drive Diagnostic Upload a keypad photo, the fault history or a parameter export from your Yaskawa GA500. InduQT compares the evidence and suggests the next useful checks.
When it happens
- At start, as soon as the output switches on
- Running, after washdown, condensation or cable damage
- With long motor cables at high carrier frequency
Likely causes and checks
1Motor insulation damaged
- Points to it
- Trips every start; motor has overheated or is wet.
- Check
- With the motor disconnected from the drive, measure motor insulation resistance.
2Motor cable shorted to ground
- Points to it
- Trips when the cable moves or after damage or water ingress.
- Check
- Inspect the cable and measure resistance between the cable and the ground terminal with both ends disconnected.
3Leakage current from cable stray capacitance
- Points to it
- Long cable (the manual cites over 100 m); insulation tests pass.
- Check
- Decrease the carrier frequency (C6-02) and reduce stray capacitance.
4Drive hardware problem
- Points to it
- Fault remains with the motor cable disconnected at the drive output.
- Check
- Contact Yaskawa; the manual lists control board or drive replacement.
Telling it apart
- GF measures current to ground. oC can also follow a ground fault, and ov can occur when ground current charges the DC bus; test insulation when these appear together.
- Megger the motor and cable only with them disconnected from the drive output terminals.
- V1000 equivalence: the V1000 manual lists GF with the same 50% of rated current definition, and notes L8-09 = 1 enables ground fault detection on certain V1000 models (2A0020 to 2A0069 and 4A0011 to 4A0038).
Relevant parameters
| Parameter | Name | Why it matters |
|---|---|---|
| C6-02 | Carrier Frequency Selection | Lower it with long cables to reduce leakage current. |
| L5-08 | Fault Reset Enable Select Grp2 | Controls whether auto restart applies to GF. |
Evidence to collect
- Keypad photo and U2 fault trace
- Insulation results for motor and cable, separately
- Cable length and C6-02 setting
- Environmental conditions at the trip
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