Finder Forcibly Guided Relays

Traditional relays use mechanical movement of metal contacts to switch a load on or off. The metal contacts have the potential to weld shut after repeated operation cycles, causing the machine to continue running even after an operator activates an emergency stop process. For this reason, safety relays are required for hazardous machinery. 

Forcibly guided relays are electromechanical switching devices that are designed in such a way that it is not possible for all contacts to be closed at the same time. If a normally open contact fails when trying to open, the associated normally closed contact cannot close when the power supply is switched off. Forcibly guided relays are used in safety circuits in combination with emergency stop switches, interlock switches and light curtains to control outputs. They can also be used to expand outputs for safety controllers and safety relay modules.

Finder 7S Series are relays with forcibly guided contacts designed for DIN rail mounting. They are used with a safety PLC to provide monitoring and logic. The 7S Series are used for SIL 2/SIL 3 safety applications.

Finder 50 Series are relays with forcibly guided contacts designed for PCB mounting. They can be incorporated into a safety relay or used to create a custom-designed PCB based safety system.

Safety Integrity Level (SIL) is a measure of safety system performance, in terms of probability of failure on demand (PFD). The higher the SIL level (1, 2, 3, and 4), the higher the associated safety level, and the lower probability that a system will fail to perform properly.