The overload relay can replace all overcurrent protective equipment (fuses or circuit breakers).

The overload relay can replace all overcurrent protective equipment (fuses or circuit breakers).

• A. False
• B. True
• C. Only for small motors
• D. In some cases with proper coordination

Answer: (A)

Overload protection is there to keep a motor from overheating during extended periods of higher-than-normal current. It senses current over time and stops the motor when it would cause damage. It does not, however, protect the wiring from short circuits or very large fault currents, which can occur much more quickly and require a device that can interrupt high fault currents immediately. Fuses or circuit breakers placed in the supply path are what protect conductors and equipment from short circuits and other dangerous faults. An overload relay alone cannot handle those high fault currents fast enough to shield the circuit, so it cannot replace all overcurrent protective equipment. In short, while overload relays safeguard the motor from overheating, they must be used with proper overcurrent protection (fuses or circuit breakers) to fully protect the system.

Overload protection is there to keep a motor from overheating during extended periods of higher-than-normal current. It senses current over time and stops the motor when it would cause damage. It does not, however, protect the wiring from short circuits or very large fault currents, which can occur much more quickly and require a device that can interrupt high fault currents immediately.

Fuses or circuit breakers placed in the supply path are what protect conductors and equipment from short circuits and other dangerous faults. An overload relay alone cannot handle those high fault currents fast enough to shield the circuit, so it cannot replace all overcurrent protective equipment.

In short, while overload relays safeguard the motor from overheating, they must be used with proper overcurrent protection (fuses or circuit breakers) to fully protect the system.