There are two types of relays: protection relays and control relays. Safety relays are classified as protection relays. Protection relays include overcurrent relays, Undervoltage relays, thermal relays, and so on. When the circuit is short-circuited or seriously overloaded, the protection relay will cut off the power supply to play a protective role.
The safety relay is a combination of several relays and circuits in order to complement each other's abnormal defects and achieve the complete function of the relay with low malfunction. By studying the safety relay working principle, you can know how does a safety relay work and better use it. The lower the error and failure value is, the higher the safety factor will be. Therefore, it is necessary to design a variety of safety relays to protect the machinery of different levels.
Safety relays are used to protect people and machines to achieve automation safety. Many types of equipment now require safety relays that are mainly used in machine tools, safety doors, elevators, etc. The safety relay itself has a logic control module and redundant safety contacts, which can replace plc in a small area.
The safety relay has a power failure protection function, that is, when the power is turned on after a power failure, the equipment needs to be restarted to operate, which means that the machine cannot suddenly restart when the emergency stop is released. The safety relay is highly safe, and there is leakage protection, short-circuit protection, and over-current protection to prevent electric shock, prevent electric current from burning electrical equipment, and prevent leakage from causing losses. The safety relay can stop the power supply of the machine in the event of a failure in the safety circuit of the machine, or the machine can no longer start when the safety circuit fails.