The illustrated motor fails to start and gives a loud hum when the start button is depressed, what should then be your first action? Illustration EL-0007

Correct Answer: Option B — push the stop button to deenergize the "M" coil

A loud hum without motor rotation indicates a locked rotor or single-phasing condition drawing massive locked-rotor current. Per marine safety standards, immediately push the stop button to deenergize the 'M' coil and prevent thermal destruction of the motor windings.