Generator runs but controller shows E8 and may shut down under load

Safety first: Working on the alternator involves hazardous voltages. Turn the controller to OFF, open the main AC breaker, disconnect the negative battery cable, and verify no AC voltage is present with a meter before touching wiring.

• Verify load: Ensure the connected load does not exceed the generator's rated kW. Temporarily disconnect large loads and recheck voltage.
• Inspect main output connections: Remove the alternator terminal cover and check that all lugs are tight and free of discoloration or burning. Tighten loose connections to manufacturer torque specs.
• Check AVR connections: Locate the automatic voltage regulator module inside the alternator housing or control compartment. Inspect its plug and wiring for looseness or heat damage.
• Measure no-load voltage: With a technician's help, run the generator with no load and measure line-to-line voltage. If it is significantly below nominal (e.g., under 200 VAC on a 240 V system), the AVR or alternator windings may be failing.
• Replace AVR if indicated: If windings test good but voltage remains low, replace the AVR with a Westinghouse-compatible unit.

Because alternator testing requires live measurements, consider having a qualified generator technician perform detailed diagnostics.