EC: PSRmini, a thin safety relay with force-guided contacts

Safety — Machine safety: Phoenix Contact's PSRmini safety relay features the world's slimmest device design (starting at just 6 mm wide) without impairing safety or switching performance for the user in any way. This is a Control Engineering 2017 Engineers’ Choice Awards Finalist.

October 13, 2016

The PSRmini safety relay is the world’s thinnest safety relay with force-guided contacts. Available in both 6- and 12-mm form factors, PSRmini safety relays provide the same functional safety and power capabilities, with a footprint up to 70% smaller, than standard 22.5-mm safety relays.

The key to this narrow design is the new force-guided elementary relay, developed by Phoenix Contact. Not only does this innovation result in lower costs for the end user, but the new elementary relays have also been approved for use in the hazardous area (ATEX, IECex, CID2), while maintaining the highest safety ratings (SIL 3, PL e).

In machine building, the PSRmini can perform on the same level as conventional safety relays, but at a fraction of the size and price. The PSRmini will interface with standard safety sensors and switch loads up to 6 A, but at 70% of the size of classic 22.5-mm safety relays. Designed with one to three enable paths, PSRmini is the most cost-effective safety relay solution, reducing both unit cost and footprint within cabinets that are already tightly packed.

The PSRmini is also a fit in the process industry. With SIL 3 ratings and hazardous location approvals (ATEX, IECex, CID2), PSRmini is ideal for electrical isolation and power amplification between the digital outputs of safe controllers and field devices. Potential-free contacts are frequently required for signal amplification (e.g., for switching high loads) or for potential isolation (e.g., to prevent losses of potential) and to transfer safety-related signals. The PSRmini was built to be the new standard for DCS/SIS output interface. It is compatible with output card test pulses used for supervisory mode and has a simplified proof test for easy maintenance and decreased cost of ownership.

Phoenix Contact,