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Frankfurt am Main, Germany , March 18, 2018

Siemens at the Light+Building 2018 in Frankfurt, Germany

Visit us at booth B56 in hall 11.0.
More info & free ticket

5SM6 AFD units

Closing the protection gap

About one-third of all fires caused by electricity are attributed to hazardous arcing faults. Particular mention is to be made to serial arcing faults. Residual current protective devices (RCDs) and miniature circuit breakers (MCBs) are not designed to detect and safely disconnect serial arcing faults and do not offer adequate protection in such cases: for example, damaged wire insulations, crushed or broken cables, bent connectors, loose contacts, or even defective electrical devices. The resulting electrical arcing faults can cause cable insulation to ignite, leading to a cable or even building fire.


Siemens closed this safety gap in the IEC market with its AFDDs (Arc Fault Detection Devices). As a supplement to MCBs and RCDs, these protection devices address all types of arcing faults, including serial ones. The AFD unit complete the comprehensive SENTRON portfolio by providing a comprehensive all-round protection of electrical installations. They enable the early prevention of various fire hazards, from the electrical line right through to the end device, protecting human lives, buildings, and assets.

Patented detection technology

The 5SM6 AFD units are based on the by Siemens patented SIARC detection technology.

  • This detection methodology – developed by Siemens for detecting parallel and serial arcing faults – is designed to continuously measure the high-frequency noise of voltage and current for their intensity, and duration and the gaps between them. 
  • Integrated filters with intelligent software analyze the signals. If anything unusual is detected, the AFD unit disconnects the circuit within fractions of a second.
  • SIARC reliably distinguishes harmless causes of faults such as those generated by drills or vacuum cleaners, from dangerous arcs.

The result: intelligent fire prevention and thus optimal and standard-compliant comprehensive protection of people and plants.


All the essentials about the SENTRON 5SM6 AFD unit
Download Technology Primer

Quick and easy installation of 5SM6 AFD units

5SM6 – your benefits

Quick, standard-compliant, and error-free configuration and planning thanks to professional software, tender specifications, and comprehensive engineering data. 

Flexible implementation of needs-based solutions for electrical installers and panel builders, while simultaneously reducing stock keeping needs – thanks to the modular portfolio offering a broad and comprehensive range of standardized accessories.

Installing new equipment or retrofitting existing systems requires little cost and efforts due to the intuitive installation of AFD units on standardized busbars or mouting rails.

The AFD units can be easily purchased either online or locally from electrical wholesalers.

Technical advisory services on products, applications, and standards as well as personal support for everything from design development to network planning and configuration.

More about the 5SM6 AFD unit
Download brochure

Successfully in use

Whether it’s in public transport applications, the food industry, or in laboratories – you can rely on 5SM6 AFD units. Learn more and convince yourself.


Order your AFD units

Better to play it safe!

With 5SM6 AFD units, you greatly increase the level of protection for people, investments and systems. You benefit from a reliable technology that, since coming to market, has already been proven in numerous areas of application, including schools, churches, laboratories, and infrastructure systems.

Find the right AFD unit to fit your needs
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