Usually, protective relays are used to guard equipment corresponding to motors, generators, and transformers, and so forth. When it comes to working an SSR, you should apply a voltage larger than the desired pickup voltage of the relay to activate the enter circuit. You have to use a voltage lower than the stipulated minimum dropout voltage of the relay to deactivate the enter circuit. Control circuit transfers the signal from the enter circuit to the output circuit. The output circuit switches on the load or performs the specified motion.