Controller displays “Overfrequency” or “High Hz” and may shut down the generator or prevent transfer.

Safety first: Turn generator OFF and disable automatic operation. Do not run with frequency significantly above rating.

Steps:

• Inspect throttle linkage: Ensure the throttle plate on the carburetor or throttle body moves freely and returns to idle when released. Clean any carbon buildup that may cause sticking.
• Check governor spring adjustment: On mechanical governors, verify that the governor spring is installed in the correct hole and not overstretched. Adjust per engine manual to bring speed back to spec.
• Controller settings: Confirm the controller is set for the correct nominal frequency (50/60 Hz) for your region.
• Electronic actuator test: If equipped, observe the electronic governor actuator. If it drives the throttle open excessively despite correct settings, the actuator or controller output may be defective and require replacement.