Safety relay is a generic name in the industry. It is composed of several relays (safety relays) and logic circuits. Its working principle and functions are completely different from those of relays. It is a composite product and has been modularized, so, The trip of Heaven calls the safety relay a safety module, which seems to be more accurate.
What are the major differences between safety relays and general relays?
Safety relays have a mandatory steering contact structure, allowing them to use auxiliary circuits to detect welding and failure of their own NO and NC contacts. In other words, both may fail, but safety relays can self-detect failures. But the general relay can't, this is the biggest difference between the safety relay and the general relay, which is why the safety circuit can only be constructed with the safety relay.