Controller displays AL22 / Alternator Overcurrent and trips output breaker

Safety first: Open the generator output breaker and isolate all downstream loads. Follow lockout/tagout procedures before inspecting electrical circuits.

• Inspect load circuits: Check for tripped downstream breakers or visible damage in load panels. Disconnect suspect loads and test the generator with no load.
• Measure current: With a clamp meter, measure phase currents under controlled load to ensure they are within nameplate ratings.
• Check alternator: If overcurrent occurs with minimal load, test stator winding insulation and resistance. This typically requires a generator specialist.
• Breaker settings: Verify that the generator main breaker rating and any adjustable trip settings match the generator's rated current.
• Reset alarm: After resolving the cause, clear AL22 and gradually reapply loads while monitoring current.

Do not repeatedly reset overcurrent trips without finding the cause; this risks severe equipment damage.