The Difference Between Safety Relays and General Relays

In today's era of advanced industrial technology, we often use safety relays when connecting electronic appliances in order to ensure the safety of the entire line, so how do we distinguish between safety relays and general relays?

1. Difference between safety relays and general relays in shape

Safety relays and general relays are different in shape and size; safety relays are bigger.

2. Difference between safety relay and general relay in terms of modules and components

Safety relay is a module, not an electronic component like a general relay.

3. Comparison of safety relays and general relays

Due to the difference in design principles: General relays cannot achieve high diagnostic coverage and can only be used in the mechanical industry and process control industry with lower safety level, so it can be considered that general relays are not safe enough. Safety relays, on the other hand, have a high diagnostic coverage, even up to 99.9% in some cases, through the requirements of the relay and the auxiliary design of the logic circuit. And in some occasions with high safety requirements, there are also regulations that certified safety relays must be used to meet the safety requirements.

4. The forced guidance structure of safety relays is different from that of general relays

A "safety relay" is not a "no-failure relay", but rather a relay that makes regular movements in the event of a fault. Safety relays have a forced guide contact structure (or other protection methods) to ensure safety in the event of contact fusion, which is fundamentally different from general relays.

5. The difference between safety relays and general relays can be seen from the perspective of relays

(1) The core component of the safety relay is the forced guide relay.

(2) General relay: Contact fusion will make both contacts ON at the same time.

(3) Forced guide relay: With the action of the internal forced-guidance lever, even if the contacts fuse, the two contacts will not be ON at the same time. The forced guide structure is a simple and effective way to detect contact fusion failure.

The main difference between safety relays and general relays: The so-called "safety relay" is not a "no-failure relay", but rather a relay that makes regular movements in the event of a fault. Safety relays have a forced guide contact structure (or other protection methods) to ensure safety in the event of contact fusion, which is fundamentally different from general relays.

CHENZHU Classic Series safety relays are cost-effective, classic, and general-purpose for a variety of industrial automation applications. It includes emergency stop buttons, safety gates, light beam devices, two-hand control buttons, safety pads and expansion modules. We welcome your online inquiries!