Controller displays E016 and indicates generator overvoltage

Safety: Isolate the generator from the load and ATS before working on the alternator or AVR. Dangerous voltages are present.

• Verify voltage: Measure line‑to‑line voltage at the generator terminals with a true RMS meter. Confirm that it is above the nominal rating when the fault occurs.
• Inspect sensing leads: Locate the AVR (often mounted in the alternator terminal box). Check the voltage sensing wires for tight connections and correct phase/voltage selection.
• Check AVR settings: Some AVRs have potentiometers for voltage and stability. Ensure they are not turned excessively high. Return to factory default positions if unsure.
• Test with reduced excitation: If safe, slightly reduce the AVR voltage setting and restart. If voltage remains uncontrolled, the AVR may be defective.
• Replace AVR: If overvoltage persists and wiring is correct, replace the automatic voltage regulator with a compatible unit specified for the Perkins‑driven alternator (e.g., Stamford, Leroy‑Somer).