Which type of relay is the most common?

The most common type of relay is the overcurrent relay. This type of relay is widely utilized in electrical systems as a protective device that detects excess current flowing through a circuit. When the current exceeds a predetermined threshold, the overcurrent relay activates and can initiate a response, such as tripping a circuit breaker to isolate the faulted section of the system.

Overcurrent relays are essential in safeguarding electrical equipment and networks from potential damage caused by overloads and short circuits. Their ability to provide timely responses to abnormal conditions makes them critical in maintaining the reliability and safety of power systems. This is why overcurrent relays are frequently found in various applications, from industrial machinery to distribution networks.

While other types of relays serve specific functions, such as voltage, frequency, or phase relays, the widespread need for overcurrent protection across different electrical installations is what solidifies its position as the most common relay type.