What is a form C relay, and when should they be used?

Form C (or changeover/CO) relays have a set of normally open contacts and a set of normally closed contacts. When the relay is not energized, the normally closed contacts are closed, and the normally open contacts are open. When the relay is energized, the opposite occurs—the normally closed contacts open, and the normally open contacts close. Form C relays are often used to switch between two circuits or control different operations simultaneously, such as in automation systems or multipurpose control applications.

Read more about relays in our white paper: “Choosing the Correct Relay for Your Application“