Controller shows E06 and the generator will not connect to load; engine may run normally.

Safety: Isolate the generator from the mains using the main breaker. Only qualified persons should work inside the alternator or on live terminals.

• Measure output: With the set running at rated speed, use a true‑RMS multimeter to measure line‑to‑line voltage at the generator terminals. Confirm it is below specification.
• Inspect AVR: Locate the AVR in the alternator terminal box of the JCB generator. Check for burnt components, loose plugs, or signs of overheating. Ensure the sensing wires are firmly connected.
• Check voltage adjustment: Some JCB AVRs have a voltage trim pot. If safe and per manual, adjust slightly to see if voltage rises. Do not exceed rated voltage.
• Inspect connections: Tighten all stator and output terminal connections. Look for discoloration or melted insulation indicating overheating.
• Brush/slip ring check (if fitted): Inspect brushes for wear and ensure they move freely in their holders. Clean slip rings with fine emery cloth. Replace worn brushes.
• If AVR faulty: Replace the AVR with the correct JCB‑specified model and re‑test.