Industrial relays with bio-based materials and energy efficiency

Siemens Smart Infrastructure has launched the new SIRIUS 3RQ4 series of coupling relays, featuring a housing made from a plastic containing 70% bio-based material. The material, Akulon^® K225-KS B-MB, developed by Envalior, is derived from used cooking oil (UCO) and produced using a mass balance approach, reducing the use of fossil resources in industrial automation components.

Sustainable materials in electrical automation
The raw material originates from biomass waste generated in the food industry, restaurants and households. As a by-product no longer suitable for consumption, its use does not compete with food or feed production. Compared to its conventional use in biodiesel, applying it in engineering plastics enables long-term value creation in electrical components.

The material provides technical properties suited for industrial applications, including thermal resistance, chemical stability and flame retardancy compliant with UL94 V-0 at wall thicknesses down to 0.4 mm. These characteristics allow integration into compact devices without compromising safety requirements.

Functional variants for different applications
The SIRIUS 3RQ4 series is available in three variants addressing different industrial use cases. The version with integrated relay output is designed for harsh environments and applications with specific safety requirements. It includes B10d values for safety-related use and ATEX certification for potentially explosive atmospheres. Optional features include gold-plated contacts for switching very low currents and coated printed circuit boards for railway applications.

The second variant consists of plug-in relays, enabling quick replacement during operation and reducing downtime.

For applications requiring frequent and silent switching, the third variant uses semiconductor output. This design offers an almost unlimited service life and switching capacity up to 6 A, comparable to conventional relays, reducing maintenance requirements in critical systems.

Energy efficiency and lifecycle design
The SIRIUS 3RQ4 relays are designed to meet sustainability criteria throughout their lifecycle. The semiconductor variant reduces energy losses by 33% compared to previous versions. The design also eliminates materials such as halogens and PFAS and supports easy disassembly and recycling at end of life.

The slim design enables optimized use of space in control cabinets, supporting higher functional density in automation systems. The devices are designed for integration with Siemens controllers within industrial automation environments.

Production, digitalization and supply chain
Manufacturing takes place at Siemens’ Amberg plant using fully automated processes, contributing to a more efficient supply chain in European markets. The products are delivered in optimized cardboard packaging, with operating instructions and documentation accessible digitally via device identification.

Joint development and engineering materials
The Akulon^® K225-KS B-MB material was developed through collaboration between Siemens and Envalior to meet technical requirements such as flow behavior in thin-wall designs and flame retardancy performance. This bio-based polyamide 6 combines renewable content with performance comparable to conventional materials used in electrical distribution applications.

In parallel, Envalior has increased its use of renewable energy in operations, covering more than 50% of global electricity demand in 2024, with a target of reaching 100% by 2030 and further reducing emissions through operational and energy-related measures.

With the SIRIUS 3RQ4 series, Siemens integrates sustainable materials into industrial automation components while maintaining technical performance and reliability in electrical and industrial applications.

Edited by Maria Brueva, Induportals editor – adapted by AI.

www.siemens.com