An arc is a visible plasma discharge which is caused by the passing of an electrical current through a medium that is usually not conductive, such as air. This occurs when the electrical current ionises any gases within the air, and the temperatures that are created by this arcing can top 6,000°C, temperatures that are, of course, more than capable of starting a fire.
So, in effect, an arc arises when an electrical current manages to jump the space between two conductive materials. An arc is most commonly caused by faulty contacts within a piece of electrical equipment, insulation that’s been damaged, a fracture within a cable and a loose connection.
As the number of domestic and commercial fires attributable to faulty electrics continues to remain high, it’s conceivable that an Arc Fault Protection Device – or AFPD – could prevent many of these from occurring. An AFPD is a protective device that’s installed within the consumer unit and its sole purpose is to prevent arc faults from occurring. They do this by employing microprocessor technology to analyse the waveform of the electricity that’s being used to spot any anomalies that would demonstrate that an arc was present on the circuit. Should an arc be detected, the AFPD will cut the power to the affected circuit and in doing so prevent the outbreak of fire. Their sensitivity means that they’re able to detect faults more effectively than other circuit protection devices, but they do need regular testing.
BS 7671:2018+A2:2022 Regulation 421.1.7 now requires that arc fault detection devices (AFDDs) conforming to BS EN 62606 be provided for single-phase AC circuits supplying socket-outlets with a rating not exceeding 32 A in the following installations:
- Higher Risk Residential Buildings (HRRBs)
- Houses in Multiple Occupation (HMOs)
- Purpose-built student accommodation
- Care homes
Mark Smith, owner of MS Electrical Services, believes that AFPDs are an important addition to electrical safety within both domestic and commercial settings. ‘In conjunction with annual PAT testing and regular fixed wire testing, devices such as an AFPD can provide ongoing protection against fire, and that can only be a good thing,’ he comments.
MS Electrical Services offer PAT testing and fixed wire testing in Cambridge, so if you’d like more information about Arc Fault Protection Devices, please contact us.