Safety Relay Working Principle

1. Introduction of safety relay

A safety relay is an electrical component used in daily life for safety to prevent electric shocks and to prevent equipment from overheating. As the name implies, it is a relay that can make regular actions in the event of a safety accident. 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 actions. The lower the error and failure value are, the higher the safety factor will be.

2. Safety relay working principle

Do you know how does a safety relay work? The safety relay interlock system has a forcibly guided contact structure, which is a necessary control part in a safety circuit. It accepts safety inputs, and deterministically outputs the switch signal to the control circuit of the device through the judgment of the internal circuit. Simply put, the safety relays are all dual-channel signal types. 

Only when the signals of both channels are normal, the safety relay in a safety and automation system can work normally; in the working process, as long as the signal of any one of the channels is disconnected, the safety relay will stop outputting. It will not work until the signals of both channels are normal and reset. Although it is not just relying on dualization alone, dualization is necessary as well. 

Mutual inspection of dual circuits is to confirm that all safety circuits have been disconnected once, and if necessary, the operator can start the operation and other conditions. From another point of view, when the input switch wiring is short-circuited or the wire sheath is damaged and the grounding happens, it is necessary to prevent the sudden start of the machine caused by that. In fact, in order to facilitate the construction of the safety circuit, the safety relay is combined with other components, and the basic emergency stop circuit and the safety circuit constitute a circuit module product called the safety relay module.