- By Keith Wong

Electrical and Mechanical Services Department (EMSD) has updated the Code of Practice (COP) for The Electricity (Wiring) Regulations in 2020. One of the updates is about the implementation of Arc Fault Detection Device – AFDD. The HKIE Electrical Division organized a technical Webinar: Latest Low Voltage Distribution Protection – AFDD & Digital Breakers on 14 Dec 2021.

According to German Federal Statistics Office, one-third of all fires reported can be traced back to dangerous defects in the electrical installation – mostly caused by hazardous arcing faults. In 2012, AFDD was invented and aimed to protection the dedicated final circuit for fire protection, in addition to the traditional overload (MCB) and residual current (RCD) protection. The devices can detect the damaged cable insulation, e. g. due to nails, screws or clips, too tight a bending radius are at risk of breaking, claw fasteners…etc. To avoid any mal-tripping due to high frequency noise such as Dimmer, Brush Motor and Switching operation, the speaker Mr. Derek Tam who is a product specialist, working in Siemens’s Smart Infrastructure Electrical Products section, introduced the SIARC technology. This detection methodology developed for detecting parallel and serial arcing faults in electrical installations is designed to constantly measure the intensity and duration of episodes of high-frequency noise associated with the voltage and current and the gaps between them. The detection and decision of tripping is based on high Frequency power vs background level, synchronization to the power waveform, high Frequency stability and duration of the arc incident. The SIARC is able to distinguish harmless causes of faults, such as those arise when operating power drills or vacuum cleaners, from hazardous arcs.

In the second section, Derek introduced the digital breakers technology with health status monitoring and communication with measuring functions. He explained how such innovations will not only empower users and facility managers to connect and monitor assets with the help of edge computing, planning of replacement to avoid unforeseeable outage, also making measurement, visualization, evaluation, and control of data possible, but also promote transparency, availability, and efficiency throughout the process. The session was wrapped up with a glance at the future of the digitalization of electrification and a Q&A session. The webinar attracted over 330 participates, it undoubtedly provided more insights and knowledge to the electrical and energy related industries.