Many motors are protected against burnout by using a _______.

• A. speedometer
• B. over current protection device
• C. tachometer
• D. velocity meter

Answer: (B)

Burnout happens when motor windings overheat from drawing too much current, especially during startup or stall. An overcurrent protection device is designed to sense that excessive current and trip or limit it before the windings overheat, protecting the motor from damage. This type of protection—found in fuses, circuit breakers, and overload relays—acts like a safety valve for current, keeping the motor within its thermal limits.

Devices that measure speed, like speedometers or tachometers, don’t control or limit current, so they don’t prevent overheating. They only report how fast the motor is running. The overcurrent protection device is the best choice for guarding against burnout.