Innovation drivers: The relay history

A relay conquers the world

We would like to tell you the story of our relay classic PLC-INTERFACE with exciting background information. Pioneering spirit, innovation, technology, applications, sustainability, and future technologies play a decisive role. Sit back and relax!

Do you have any questions on the subject of relays or switching? Or are you looking for an individual solution? Please do not hesitate to contact our experts.

Relay modules on a DIN rail for installation in an application
Insight into the PLC-INTERFACE relay with lead-frame technology

Inner workings with lead frame of a PLC interface relay

Switching signals reliably – in tight spaces ​

Relay systems from Phoenix Contact form the powerful and reliable interface between control and system peripherals. The lead-frame technology of the PLC-INTERFACE relay series provides the solid foundation for reliably switching, isolating, and amplifying signals. In addition, electromechanical and solid-state relays are used – this combination proves itself day after day in millions of switching operations in a multitude of applications and in relay switching.

Quality is a priority at Phoenix Contact, so even small details are of great importance to us. With our own plastic and metal parts manufacturing facilities, we produce the parts that form the basis of the high-quality components. 100% of the products are tested during the process. To ensure that innovative product ideas are continuously implemented in design and development departments, expertise and in-house skills are being further extended.

Passion, innovation, and pioneering spirit became a milestone in relay technology in 1997: Lead-frame technology was integrated for the first time into relay modules from Phoenix Contact with an overall width of 6.2 mm. Even today, this is unique on the market.

Carsten Thörner - Phoenix Contact, Vice President (Interface Components)
Carsten Thörner, Vice President Interface Components at Phoenix Contact
In use worldwide
There is always something to switch
Coupling relays, with an electromechanical design (EMR), as solid-state relays (SSR), or as hybrid relays: Find out all the background information on the classic PLC-INTERFACE relay from Phoenix Contact, which has permanently changed and shaped the world of switching. From wind power, through logistics, to wastewater plants – PLC-INTERFACE has been switching plants in all parts of the world, ever single day for 25 years.
Discover the installation locations
Control cabinet builder installing a PLC relay with logic module
Interactive Image Map: Places of application of PLC-INTERFACE with the examples of wind, shipbuilding, machine building, logistics, water and wastewater, the process industry, and infrastructure
Railway technology
Relays and solid-state relay modules for railway applications ▪  In accordance with DIN EN 50155 ▪  Also SSR in accordance with EN 61373 ▪  Up to temperature class TX
Highly compact relay modules with DNV approval (including extensive accessories) PLC-INTERFACE Location Classes ▪  Temperature D ▪  Humidity A ▪  Vibration B/C ▪  EMC B
Renewable energies
Space-saving relay modules for onshore and offshore applications ▪  Long service life with hybrid technology ▪  Smooth switching through the combination of semiconductor and relay
Space saving relays and solid-state relay modules for sorting and braking applications with high clock rates ▪  Switching current up to 10 A ▪  Clock rates up to 300 Hz
Process industry
Highly compact relay modules with ATEX, IECEx, and UL approval for zone 2 applications. Additional versions with increased immunity against interference for long control lines. ▪  Switching currents up to 10 A and multiple input voltages ▪  High ambient temperature range +70°C ▪  Nonsensitive to interference on signal lines ▪  High drop-out voltages for unambiguous switching and signal states ▪  Relay modules with push-in and screw connection
Machine building and systems manufacturing
Extensive product range with special types such as relay modules ▪  Safe feedback through force-guided contacts in accordance with DIN EN 61810-3 Type A or innovative hybrid technology ▪  High-level machine and system availability
Relay modules for high inrush currents, e.g., for road and tunnel lighting systems ▪  Maximum inrush currents up to 800 A for AC and DC loads ▪  High ambient temperature range ▪  Relay modules with push-in and screw connection
Water and wastewater
Relay and solid-state modules designed for universal use ▪  6.2 mm overall width for space-saving use ▪  High system availability with tool-free relay replacement
Close-up of a relay module with lead-frame technology

Lead-frame technology Your advantages:

Lead-frame technology enables:

  • Pressed-in electronic components such as diodes, RC combinations, and LEDs for integrated functional and protective circuits directly in the relay base
  • Optimized thermal management reduces localized heating and extends the service life of electronics components
  • Proven technology for highly compact relay systems
  • Sustainable construction with easily separable construction elements
  • Easy wiring with Push-in and screw connection technology

Learn more about the background of the relay history:

Production of the PLC-INTERFACE relay – inner workings are pressed into the housing
People discussing a project in front of a computer
Hand holding a sheet with a virtual globe and sustainability icons
A networked world for the representation of the All Electric Society
Production of the PLC-INTERFACE relay – inner workings are pressed into the housing

An exciting relay story full of pioneering spirit, innovation, and passion.

We have been developing innovative and technologically leading relays for you for over 25 years and have shaped the market of industrial interface coupling relay modules and created a new standard. The PLC-INTERFACE relay system is the high-performance interface between the controller and system I/O devices. We have been providing a comprehensive range of highly compact pluggable relays and solid-state relays since 1997. The product range has been and continues to be extended constantly. In addition, extensive accessory and system cabling solutions are available for your application.

People discussing a project in front of a computer

All key conformities and approvals

With our relays, you have the assurance of safely meeting regulatory requirements and your customers’ needs through innovative technology. But we do not just comply with the standard – you can expect more: Whether for railroad applications, machine building and systems manufacturing, or potentially explosive atmospheres, our product range always includes the right relay module with the necessary approval and country conformity for your application.

Hand holding a sheet with a virtual globe and sustainability icons

Replaceable relays and recyclability of relay modules

Sustainability and climate change are global challenges of our time. For this reason, we focus on sustainable value creation – from development, through manufacturing, right through to logistics. To conserve resources, we reduce electricity consumption at our sites and rely on green electricity, green gas, waste heat, geothermal energy, and energy generated from renewable sources. Our relays and relay modules provide concrete support for your philosophy of sustainability: The replaceability of the relay in combination with a long base socket service life ensure the sustainable operation of your system.
By using lead-frame technology, the PLC-INTERFACE relay can be recycled very easily compared to PCB technology.

A networked world for the representation of the All Electric Society

Making sustainable technology and processes more energy and resource-efficient

We are empowering you for key future subjects, such as carbon-neutral energy and power-to-X, with the help of electrification, networking, and automation: relays and switching devices effectively support the All Electric Society in switching AC and DC clusters. Benefit from consistent product and 3D data in your planning and in the operation of your plant. The clipx ENGINEER engineering software from Phoenix Contact creates digital and seamless processes from planning through to production and thus ensures efficient and future-oriented planning.