Protect your machinery or plant with safety relays. Functioning much like a regular relay, safety relays are more specifically designed to implement safety functions in many different environments. Our extensive range has everything you need to ensure that, should an error occur, a safe and reliable response is initiated.

With control relays from Omron Safety to Pilz PNOZ S4 safety relays, emergency stop safety relays from Schneider Electric to PCB terminals from IDEC Corporation, you’re sure to find the safety relay you need to ensure the safe operation of equipment and help keep your business and employees safe.

What is a safety relay?

Safety relays are devices that implement safety functions. In the event of a hazard, a safety relay will work to reduce risk by initiating a safe and reliable response as well as monitor the integrity of its function.

By monitoring machinery or plants for potential errors, safety relays can prevent injury and reduce risk in the workplace. Safety relays protect both machinery and employees, preventing potentially expensive maintenance and equipment replacement, as well as ensuring that your business meets the required safety standards.

How do safety relays work?

Safety relays have a clear structure and are simple to operate. They are often used in conjunction with other safety relays, with each monitoring one specific function. This enables you to monitor multiple outputs and measurements at once on a single piece of machinery. It is possible to change how each safety relay is used with other relays to achieve different results. The design and functionality of using multiple safety relays is not too dissimilar to normal relays, with a few exceptions. Like a common relay, safety control relays can use a contact that can be open or closed, however, safety relays have the ability to evaluate and control outputs based off the readings.

Thanks to their compact design and high reliability, safety control relays have become an integral component of any plant or machine in which safety functions have a role to play. If installed correctly, a safety relay will continue to function even if a fault in the device occurs or if a fault is caused by a sensor malfunctioning.

What are the different types of safety control relay?

Safety relays can be single function or multi-function.

Single function safety relay – Used to monitor a specific type of activity, single function safety relays are designed to provide basic and advanced safety functions, such as time delays and speed monitoring. They are also designed to be used in specific applications such as two-hand control, muting, and the control of pressure sensitive safety mats and edges.

Multi-function safety relay – Used in place of several single-function individual units. Multi-function safety relays offer many benefits, including simpler installation and less wiring. Because fewer individual units are needed, using multi-function relays can also free up panel space, as well as giving you greater flexibility to make changes within the design or panel.

Force-guided safety relay – Contacts of a force-guided safety relay are made to open and close by a guide connected to the armature. If an NO contact becomes welded, all NC contacts will maintain a minimum distance of 0.5 mm when the coil is not energized. Likewise, if an NC contact becomes welded, all NO contacts will maintain a minimum distance of 0.5 mm when the coil is energized.

Where would you find a safety relay?

Safety relays are often found in the following control devices:

Two-hand controls
Movable guards
Light curtains, light barriers, and light grids
Magnetic switches
Safety mats and pressure-sensitive mats
Three-position devices
Non-contact safety sensors
Safety switches
Emergency stop buttons

Because of where safety relays are used, they are tested much more rigorously compared with normal relays and have a much lower failure rate.

Why choose RS for your safety relays?

As North America’s largest authorized distributer of industrial control equipment from leading manufacturers, you can rest assured that our range of safety relays meet the highest industry standards of performance and safety to help you create a safe working environment.

If you have a specific relay you need, for example a Pilz PNOZ S4, you can enter the make and model into the search bar. Alternatively, you can narrow down the result by using the search functionality tools.

Feel free to contact our team of experts if you need assistance, and you don’t forget you can also find advice and further reading on our expert content hub.