Safety relay

Safety relays are devices that generally implement safety functions. Safety relays are devices that generally implement safety functions. Relays and contactors were used to control plant and machinery in the early days of control technology. In the event of a hazardous situation, the actuator was simply isolated from the energy supply. This type of protection system could be manipulated in the event of a malfunction, disabling the protective function. Special relay circuits, such as the three-contactor combination, were the first designs to come out of deliberations into how this could be avoided. These device combinations led to the development of the first safety relay from the German automation manufacturer Pilz, the PNOZ. In the event of a hazard, the task of safety functions (e.g. E-STOP, safety gate or standstill monitoring) is to use appropriate measures to reduce the existing risk to an acceptable level. These many safety functions include: As such, safety relays monitor a specific function. When connected to other safety relays, they guarantee full monitoring of a plant or machine. They meet the requirements of EN 60947-5-1, EN 60204-1 and VDE 0113-1.