Fire safety and electrical consumer units
Periodic inspection of electrical distribution boards, consumer units and associated circuits remains the key defence against unsafe or potentially unsafe installations. It’s worth noting that additional safety solutions for enclosed equipment, working in tandem with periodic inspection observations for improvement, can be highly effective.
In this blog we explore how fire suppression solutions, often called fire tubes, offer additional protection against risk of fire within consumer units caused by overheating of electrical wiring.
First off, we should summarise key regulatory information governing the safety of consumer units. Electrical enclosures such as distribution boards and consumer units hold standardised ingress protection ratings, often referred to as International Protection (IP) ratings. These IP ratings indicate the level of resistance provided against intrusion by or contact with a range of solid and liquid objects – solid objects including hands, tools and cables, and liquid objects including water ingress from various angles.
Part of the IET Wiring Regulations in the UK, Regulation 416.2 Barriers or Enclosures governs the safe design and functioning of electrical consumer units. Barriers or enclosures are intended to prevent contact with live electrical elements. Within the consumer unit, live elements must be inside an enclosure or protected by a barrier providing a level of protection rated to IPXXB or IP2X. The horizontal top surface of a barrier or enclosure (a consumer unit) should provide protection rated to at least IPXXD or IP4X.
Returning to the role of periodic inspection, should a competent person inspect a consumer unit and find that it does not meet Regulation 416.2 nor can the unit be safely and effectively repaired at the point of inspection, a C2 observation would be noted in the Electrical Installation Condition Report (EICR). A C2 observation means that the consumer unit requires upgrading. A C3 observation code is recorded where improvement is recommended. C3 observations are often made where a consumer unit manufactured with combustible material, such as plastic, is not additionally protected by enclosure within a non-combustible housing such as a steel cabinet.
In situations such as C3 observations being recorded for the absence of protection against thermal effects and a consumer unit being made from combustible materials, involving Regulation 421.1.201 we’ve supported clients with advice on additional, effective low-cost solutions to suppress fire inside plastic consumer units.
Instead of a full consumer unit upgrade, a fire tube can be easily installed inside the lid of a plastic consumer unit. These sealed thermoplastic tubes react when exposed to high temperatures caused by overheating electrical wiring. Fire tubes release a liquid which immediately extinguishes fire, thereby preventing the spread of fire outside the consumer unit. In many cases where the fire tube has burst and suppressed fire, the consumer unit itself also remains intact and experiences minimal damage. Fire tubes undoubtedly provide a powerful and extremely cost-effective alternative to replacement of consumer units.
Thanks for reading. We welcome comments, feedback and suggestions for future safety compliance topics.