The controller shows 'Underfrequency' or 'Low Hz'; the transfer switch may drop the load.

Safety first: Isolate the generator from the load. Turn OFF the unit and disconnect the battery negative terminal before mechanical adjustments.

Steps:

• Reduce load: Remove non-essential loads and see if the frequency returns to normal. If it does, the generator was overloaded.
• Check fuel and air: Inspect the air filter, fuel pressure, and fuel line for restrictions. Correct any issues.
• Governor linkage: Inspect and clean the governor linkage and throttle plate. Ensure there is no binding and that springs are intact.
• Frequency measurement: With a meter capable of reading Hz, verify the actual frequency at the generator output. If the controller reading is wrong but the frequency is correct, the sensing circuit or controller may be faulty.
• Professional adjustment: Fine-tuning governor speed should be done by a technician to avoid overspeed conditions.