Answer
When a generator trips on overspeed (typically at +15% of rated RPM), the Chief Engineer must verify the plant safety before attempting a restart:
Blackout Management: Ensure the Emergency Generator has started and taken the emergency switchboard load. Restart and synchronize an alternative, healthy auxiliary engine to restore main power.
Determine Root Cause:
Sudden Load Rejection: Check if the main circuit breaker tripped under heavy load, causing the engine to rapidly accelerate before the governor could react.
Governor Failure: Inspect the governor fuel rack. If the linkage got physically stuck in the maximum fuel position, the engine will run away.
Fuel/Gas Ingress: Ensure there is no oil mist carried over through the crankcase breather or a leaking turbocharger seal entering the air intake manifold, which can cause the engine to auto-ignite independently of the fuel pumps.
Safety Reset: Manually inspect the overspeed trip weight or electronic sensor assembly. Turn the engine manually with indicator cocks open to verify there is no mechanical interference before resetting the mechanical overspeed trip lever and attempting a no-load test run.