Which device is primarily used for protecting motors from overcurrent?

A circuit breaker is primarily designed to protect electrical circuits, including motors, from overcurrent conditions. When the current flowing to the motor exceeds a certain threshold, typically caused by a fault condition or overload, the circuit breaker interrupts the electrical flow, thereby preventing damage to the motor due to overheating or failure.

In motor applications, overcurrent can result from various factors such as mechanical failures, excessive load, or short circuits. By detecting this condition and acting quickly, the circuit breaker helps ensure the safe operation of the motor and minimizes downtime and repair costs.

While relays can also aid in protection systems, their primary function is typically to control circuits rather than directly interrupting power flow under overcurrent conditions. Capacitors are used in systems primarily for power factor correction or starting assistance in motors, and transformers serve the purpose of voltage transformation and isolation, but they do not provide overcurrent protection.