One commonly used protection scheme is the overcurrent protection scheme. In this article, we. What Is A Relay? Relays are electrical components that can be used to switch large electrical loads by only using a small electrical current. If you would like to learn more about relays please check. Protection schemes are an integral part of power systems as they ensure the safe and reliable operation of electrical networks. Contacts: Conductive points that complete or break the circuit. Types of Protective Relays: Protective relays are categorized by their mechanism (electromagnetic, static, mechanical) and function. Relays are key in home automation, handling switching and protection.