Controller shows E008, generator stops and indicates underspeed / underfrequency

Safety: Remove load from the generator before troubleshooting speed issues to avoid stalling under load.

• Check fuel system: Confirm filters are clean and fuel supply is unrestricted (see E002 steps). A starved engine may not maintain rated speed under load.
• Inspect throttle/actuator linkage: On mechanical governor systems, check the linkage from the governor to the fuel pump for stiffness, corrosion, or misadjustment. Lubricate pivot points and ensure free movement.
• Electronic actuator test: For sets with an electronic governor actuator on the fuel pump, observe its movement during start and load changes. If it does not respond or moves erratically, test supply voltage and control signal from the governor module.
• Controller settings: Verify rated speed, droop, and PID parameters in the governor or generator controller. Incorrect tuning can cause slow response and underspeed trips.
• Load test: After corrections, run the generator and gradually apply load while monitoring frequency (Hz). It should remain within the specified band (typically ±1–2 Hz).