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We live in a world where safety is always the number one priority. The safeCAP product series enables users, and workplaces alike to ensure that all humans and machines are operating with the highest level of safety. This article aims to compare and contrast CAPTRON’s safety switches and other common switches available in the industrial market.


Before we dive into each product and/or technology, it’s important to understand the reasoning behind using safety control systems. Capacitive two-hand controls from CAPTRON are developed, manufactured and sold specially for daily, fatigue-free and ergonomic use on a continuous basis when operating heavy machines and plants where there is a risk of injury, for example operating presses and punching systems.

Safety switches are highly targeted and integrated in applications where an operator must keep all of their senses focused on the operation – hence why two hands are mandatory on the switch. In any heavy machinery environment, it’s quite easy for a user to put their hands in an unsafe area, or improperly operate the machine. With two-hand control, users are mandated to hold both hands for actuation of the switch, unlike our SENSORswitches which only require one switch for actuation. Essentially the safeCAP is a system rather than just a switch!



CAPTRON launched the SC3 for use as a capacitive two-hand control: introducing a new compact, compatible and designed for the standard installation of Ø 22.5 mm.The SC3 product series is certified by TÜV SÜD as a safety system with PhotoMOS relay NO and can be used in conjunction with current Siemens safety relays as a capacitive two-hand control. For easy and flexible assembly, two identical SC3 buttons are installed, instead of a button A and a button B, as the SC4 series required.

To enable space-saving installation, the SC3 has a reduced external diameter of 54 mm width, 19.4 mm height and a touch surface of Ø 50 mm. The user receives feedback on the machine’s operating status via two bright LEDs, these lighting up green and yellow. Operation with disposable or working gloves – as normal in production automation – is also possible.

Additional protection elements such as the protector or operator control allow modular combinations in line with the application. Thanks to their design compatible with relevant standards, these combinations fulfil all requirements for two-hand controls of type III C corresponding to DIN EN 574. The safety-related features are designed with category 4 and Pl e according to DIN EN ISO 13849-1.




SC4 series allows heavy industrial automation machinery and systems to be operated safely and without pressure and meets the very highest safety requirements of Category 4 under PL e to DIN EN ISO 13849-1.  This only has a housing width of 22.5 mm and is to be attached to a standard rail. The safeCAP corresponds to DIN EN 574 as a two-hand control type III C.

CAPTRON supplies the SC4 series in Basic, Protect and Complete sets. The additional safety elements such as the Protector or the control desk also provide protection from outside interference and satisfy all the requirements for two-hand safety controls under DIN EN 574.

The touch area has a diameter of 63 mm making it very large and easy to use. The user receives optical feedback through 8 red and 8 green LEDs. The safeCAP4 must be purchased with two separate switches, SCA4 and SCB4. These switches work in conjunction as they are connected to the safety relay. The concept is supported by two clearly distinguishable plug connections with connector cables in black (A) and yellow jacket colours (B) for the connection with the two-hand safety relay MasterCAP MCR-225.


Common Safety Switches:

There are many other two-hand control systems available within the industrial automation market. Some which have certain pro’s and con’s over the other. Unlike CAPTRON’s safeCAP systems many other manufacturers include small surface areas which reduces the ergonomic feeling and overall user ability for an operator, or mechanical actuation. Another very standard switch in the field, is a two-hand control which operates with only a finger rather than a hand – this design may look sleek, yet over repetitive use it can become tiring for the end-user. Other common two-hand systems must be used with a specific safety relay, whereas CAPTRON products are greatly compatible. When designing a safety system for a machine, engineers or designers choose CAPTRON for a solution that is easy to use, certified, and compatible.



CAPTRON safeCAP Key Features:

  • 100% water and oilproof
    Protection class IP69K, fully sealed in casting resin
  • Extremely long service life
    Over 100 million switching cycles
  • Impact-resistant & robust
    Protection rating IK08, cannot be destroyed by lighter flames and blows to the switch surface
  • Certified by
    Underwriter Laboratories (SC3) , PL e DIN EN ISO 13849-1 (SC4)
  • Certified by TÜV Süd
    EN 574:1996+A1, IEC 60947-5-1, EN ISO 13849-1, 2006/42/EC  (SC3)
  • Compatible with Siemens safety relay
    3SK1 Advanced, 3RK3 MSS, Simatic F-CPU 09 (SC3)
  • Touch sensor
    Maximum ease of use, effortless, no strain on wrists


If you’re interested and would like to learn more please contact us! As always, your CAPTRON North America Sales team is happy to assist with product configuration, pricing, support, and much more. We can be reached via or via (914)-619-5422.

Configure your safeCAP NOW

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