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Interested in a Smaller Relay - SIS3



SIS3 Series


Press Release

MORE Force Guided
Safety Relays

High Speed Train Engineers need look no further. Willow Technologies Limited present the smallest forcibly guided (safety) relays currently available on the market: Elesta Relays SIS3 series – with category III protection over voltage.

John Merrill, Product Manager – Relays at Willow commented “Fully compliant with DIN standard EN 50205 type ‘A’, the tiny SIS212 relay measures just 29.2 x 16.6 x 16.5mm. It is a forcibly guided PCB safety relay with three contacts.”

Two of the contacts are configured as 2NO (normally open) and the other as 1NC (normally closed). The contact nearest the coil is the normally closed contact and is mostly used for control functions or feedback purposes. Further from the coil, the 2 NO contacts are used for the output or load. All contacts are designed for a nominal switching capacity of 250Vac at 6A (AC-1) and the contact material is well-proven AgCuNi + 0.2-0.4µm Au, permitting reliable switching of small control signals of a few mW, to a maximum of 1500VA.

A safe electrical separation exists between control and output side. Coil and control contacts are separated from the two output contacts by double and reinforced insulation, with clearance and creepage distances > 8mm.

“At AEC we can provide all common coil voltages between 5 VDC and 110 VDC, with standard 0.6W or sensitive 0.4W coils.” continued Merrill.

Elesta are the world’s foremost manufacturer of high quality forcibly guided relays, designed for public protection. Typical application areas for SIS3 relays include sensor technology, photoelectric cells, light curtains, foot mats, railways and frequency changers.

AEC offers the full line of Elesta forcibly guided contact safety relays which comprise 24 separate relay series, capable of switching currents from 3mA to 16A and can offer up to 10 contacts in a single relay. All Elesta Relays are RoHs compliant and carry UL, cUL and TÜV approvals.

“With demand for smaller components constantly increasing, the SIS3 series is unquestionably an apt and popular choice. Elesta relays should be considered wherever people or property must be protected and where a monitored contact is required.” Concluded Merrill.

Please refer to our website for additional product details and contact us at if samples or prompt technical support are required:

Editor Information


Willow Technologies Limited, founded in 1989, provides solutions to customers by designing, manufacturing and supplying components and systems to the electrical and electronic marketplace across the globe. Specialists in switching, sensing, resistive and hermetic seal solutions, the company has a wide portfolio of technologies and over 100 years of application experience. With an in-house engineering capability and a production facility for rapid prototyping of custom parts, the company is well equipped to develop products matching customer specific application requirements. Willow is ISO9001: 2008 Registered.

For further information please contact:

John Merrill, This e-mail address is being protected from spambots. You need JavaScript enabled to view it ,+44 (0) 1342 717102.

Willow Technologies Ltd. Unit 3 Borers Yard, Borers Arms Road, Copthorne, West Sussex, RH10 3LH, UK

Tel: +44 (0) 1342 717102, Fax: +44 (0) 1342 717014, Email:

CORPORATE: Solid State Group

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