What component is crucial for protecting motors from excessive current?

• A. Capacitor
• B. Overload relay
• C. Contactor
• D. Transformer

Answer: (B)

The overload relay is a vital component in motor protection systems because it is specifically designed to detect and respond to excessive current flowing through a motor. When motors operate, they can sometimes draw more current than their rated capacity, especially under load conditions or in the event of mechanical failure. An overload relay continuously monitors the current and, if it exceeds a predetermined level for a set duration, the relay will open the circuit, disconnecting the motor from the power supply.

This protective measure helps prevent damage to the motor windings and other electrical components, avoiding overheating and potential burnout. The overload relay functions by using either a thermal mechanism or an electronic system to sense overcurrent conditions. Therefore, having this component ensures that the motor can operate safely and reliably, preventing costly repairs or replacements.

In contrast, capacitors primarily store and release electrical energy and are not designed for overload protection. Contactors serve to switch electrical circuits on and off but do not provide overcurrent protection, and transformers are utilized for voltage transformation rather than motor protection.