Which device is primarily responsible for preventing short circuits in a motor circuit?

The device primarily responsible for preventing short circuits in a motor circuit is the circuit breaker. Circuit breakers are designed to automatically interrupt the flow of electricity in the event of an overload or short circuit condition. When a short circuit occurs, the current increases drastically, which can cause significant damage to the electrical components if not addressed immediately. A circuit breaker detects this sudden surge in current and trips, opening the circuit and stopping the flow of electricity. This protection mechanism helps in preventing equipment damage and potential fire hazards due to short circuits.

While other devices like fuses also provide protection by breaking the circuit, they do so by melting and need to be replaced after each event. In contrast, circuit breakers can be reset after tripping, making them a more convenient choice for protecting motor circuits from short circuit conditions.