Generator runs but voltage is too high, E09 overvoltage alarm on display

Safety first: Turn OFF the generator and disconnect it from all loads. High voltage can damage appliances.

• Verify voltage selector: On Scheppach models with a voltage selector switch or controller setting, confirm it is set to the correct output (e.g., 230 V single‑phase or 400 V three‑phase). Do not change settings under load.
• Inspect neutral and sensing leads: Remove the alternator terminal cover and locate the AVR sensing wires (often connected between a phase and neutral). Ensure all connections are tight and not corroded. Repair any loose or burnt terminals.
• Check neutral bond: Confirm the generator neutral connection is secure at the alternator and terminal block. A floating or intermittent neutral can cause unstable voltage.
• Replace AVR: If wiring is correct and E09 persists, replace the AVR with the exact Scheppach‑specified part. Mount it securely and reconnect all wires as per the diagram.
• Test under light load: Start the generator and measure voltage with a true‑RMS meter. Confirm it remains within ±5% of nominal under light and moderate load.