A:
Safety relays are needed in safety circuits to ensure that the equipment can reliably cut off dangerous actions in emergency or abnormal situations, thereby ensuring the safety of personnel and equipment. Its role is far beyond that of ordinary relays for the following reasons:
✅ Why safety relays are needed:
1. Forced guided contact structure
It has a forced opening/closing function to prevent false operation when the contacts are stuck, which is not available in ordinary relays.
2. Fault self-checking and feedback monitoring
It can detect disconnection and short circuit of the input signal circuit, as well as the feedback status of the actuator (such as contactor).
3. Redundant design ensures safety
Usually dual-channel input is used, so that the system can still stop safely even if one circuit fails.
4. Compliance with safety standards
Meet the design requirements of international safety standards such as ISO 13849 and IEC 61508 to ensure that the safety level of PL e or SIL 3 is achieved.
5. Key safety signal control
Control key equipment such as emergency stop buttons, safety light curtains, and safety door locks to ensure reliable signal execution.
