- Error code
- 300–399
- Category
- Leakage current
- Manufacturer
- KOSTAL
- Models
- Piko / Plenticore
1What the error means
Shutdown due to leakage current. The inverter measured a leakage current to earth above the permitted level and disconnected immediately, just as an RCD would. The whole 300–399 group concerns this fault.
2Possible causes
- Ground fault in the PV generator
- Moisture in the installation
- Faulty module or cable
- Fault in the inverter's residual current sensor
3What to do
- Check the PV generator for a ground fault, especially after rain.
- Measure the insulation resistance.
- If the fault also appears with the PV generator disconnected, the fault is in the inverter.
Codes covered
This fault appears with the codes 300–399. The manufacturer documents them as a single fault — the number indicates the stage or the phase in which it was detected.
4Repair by Aineas
You send the inverter to our lab in Thessaloniki. We diagnose it, inform you of the fault and the cost, and the repair starts only after you approve it. Every inverter is tested under simulated operating conditions before delivery.