Controller shows E09, generator shuts down and will not carry load

Safety first: Turn OFF the generator, open the main breaker, and verify zero voltage at the output before inspection.

• Step 1 – Confirm overvoltage: If possible, review the controller event log to confirm that line voltage exceeded the setpoint. Do not reconnect the generator to the building until voltage is stable.
• Step 2 – Inspect AVR sense leads: Locate the AVR and identify its sensing wires (often connected to two phases or phase‑neutral). Ensure they are connected to the correct terminals and are tight. Loose sense leads can cause the AVR to over‑excite the alternator.
• Step 3 – Check for wiring damage: Follow the sense wiring from the alternator to the AVR and controller. Repair any damaged insulation or loose connectors.
• Step 4 – Replace AVR if unstable: If voltage remains high or fluctuates excessively when the generator is run with no load, replace the AVR with a genuine Multiquip unit.
• Step 5 – Verify controller settings: Using the Multiquip controller menu, verify that nominal voltage and overvoltage thresholds are set according to the installation (e.g., 120/240V, 208V, 480V). Adjust only if you have the installation documentation.
• Step 6 – Clear code and retest: Clear E09 and perform a controlled test with a voltmeter connected. If voltage remains within spec under varying loads, return the unit to service.