1) Larger shape: The size of the safety relay is different from that of the ordinary relay, and the safety relay is larger.
2) Module instead of component: Safety relay is a module, not an electronic component like ordinary relay.
3) Red-yellow: The safety relay has a proprietary color, generally yellow, or red, or these two colors are the main colors (just like our explosion-proof safety design, the dangerous side and the intrinsic safety end are usually marked with blue same). Of course, these are just superficial phenomena.
4) [Core] safer: due to the difference in design principles: ordinary relays cannot achieve high diagnostic coverage (DC), and can only be applied to machinery industries with lower safety levels such as Cat.B / 1, process control industry SIL1, Therefore, it can be considered that ordinary relays are not safe enough. And Anji through the requirements of the relay and the auxiliary design of the logic circuit, its diagnostic coverage is high, and some can even reach 99.9%. And in some places with high safety requirements, there are regulations that must use certified safety relays to meet safety Claim!
5) Mandatory guidance structure: "safety relay" is not "relay without fault", but to make regular action when failure occurs. The safety relay has a mandatory guided contact structure (or other protection methods), which can ensure safety in the event of contact melting, which is completely different from the general relay.
6) From the perspective of the relay, the difference between the safety relay and the ordinary relay can be seen:
The core component of the safety relay is the force-guided relay. From the perspective of the relay, the difference between the safety relay and the ordinary relay can be seen.
Ordinary relay: The contact fusion occurs, which will cause the two contacts (NO / NC) to turn ON simultaneously.
Forced guide relay: Under the action of the internal forced guide rod, even if the contacts are sintered, it will not cause the two sets of contacts (NO / NC) to simultaneously turn on. The forced guidance structure is a simple and effective way to detect contact fusion faults.