Controller displays 'Undervoltage' or 'Low AC Voltage'; lights may dim or transfer switch may not transfer to generator.

Safety First: Turn OFF the generator breaker and utility power before opening panels. Use insulated tools and a properly rated multimeter.

• 1. Remove all loads: Ensure the generator main breaker is OFF so the unit runs with no load while testing.
• 2. Inspect alternator connections: Open the alternator terminal box and check all lugs for tightness and signs of overheating. Tighten loose lugs and replace any burnt connectors.
• 3. Check AVR and sensing leads: Verify the AVR harness and voltage sensing wires are secure and undamaged. Look for rubbed-through insulation or rodent damage.
• 4. Measure no-load voltage: Start the generator in manual mode with breaker OFF. Measure line-to-line and line-to-neutral voltages. If voltage is significantly low (e.g., <210 V line-to-line on a 240 V system), suspect the AVR or stator.
• 5. Test with reduced load: If voltage is normal at no load but drops excessively under small load, the stator windings may be partially shorted or the AVR is weak. Replacement of the AVR or alternator stator assembly is typically required and should be done by a qualified technician.