April 2021

38 | Plant & Works Engineering www.pwemag.co.uk April 2021 Fire & Security SPECIAL FOCUS F ires can strike at any time and without warning, so businesses should be empowered by the latest technologies to prevent them before they can build to a crisis. Consultant engineers have a real opportunity to show leadership in improving safety, stepping beyond the minimum requirements to protect their business and its most valuable assets. Prevention is by far better than cure when it comes to electrical fires. Engineers should look beyond simply tackling overloads and short circuits and examine a range of connected solutions that can stop a fire before it even has a chance to begin. This drastically reduces the cost of damages and repairs, while giving building operators unrivalled visibility. Connected protection is crucial at every level of the circuit, from the switchboard to distribution. A centralised system for equipment monitoring and detection provides building managers with all the information they need to keep fire risk under control, and therefore protect staff, property and business. A priority for consultant engineers During the design and implementation phase, the consultant engineer’s role is traditionally to respect and master the local standards. They should ensure all components and parts of the circuit comply with the latest wiring rules, electrical and building codes. Yet for enhanced safety they should also be willing to look beyond the standards of the day. Today’s regulations do a good job of protecting buildings from the dangers of short circuits and overloads, mostly by mandating the use of circuit breakers. However, consultant engineers should also be aware of the risks posed by circuit deterioration and mistakes made during the installation. Loose cabling and faulty insulation or connections – even something as small as an untightened screw – can significantly increase a Electrical fires: The danger no organisation can afford to ignore Of all the risks that face modern commercial buildings, electrical fires are one of the most common and damaging. Fire endangers health, property and the business itself – with 25% of businesses who suffer a fire never reopening. Stewart Gregory* reports. circuit’s fire risk. It’s up to consultant engineers to know their market and provide solutions that go beyond the minimum to detect and prevent electrical fires. Work smart A stitch in time saves nine. While tackling overloads and short circuits is crucial, engineers must go further, examining a range of connected solutions that can stop a fire before it even has a chance to begin. Acting pre- emptively can drastically reduce the cost of damages and repairs and provide building operators with unrivalled visibility of their facility. Connected protection is crucial at every level of the circuit, from the switchboard to distribution. A centralized system for equipment monitoring and detection will provide the building manager with all the information they need to keep fire risk under control. For optimal protection, organisations should employ smart, connected solutions that detect fire and the risk of fire at every level. This means additional protection for the switchboard and the circuit at all levels of the electrical installation, underpinned by a centralised system for monitoring and pro-active action. Using Residual Current Devices (RCDs) against insulation faults triggered by earth leakage currents exceeding 300mA, is a familiar solution. Engineers now have access to more effective earth leakage protection solutions with the same footprint as a classical overload and short-circuit protection. Products can now also offer permanent earth leakage current measurement which, when connected to a monitoring system, allows pre-alarming and monitoring during the time of any drift in the insulation. Identify vulnerabilities Unprotected electrical switchboards are especially vulnerable to fire risk. The equipment is susceptible to rodent infestation and internal overheating, issues that can often go unnoticed until it is too late. The IEC 61439-2 Low-voltage switchgear and control gear assemblies – Part 2: Power switchgear and control gear assembly’s standard addresses these risks, making compliance a must. However, fulfilling these design and manufacturing rules for switchboards does not eliminate the risk of connection failure. A critical sequence of events can occur. First, increasing electrical contact resistance accelerates further deterioration. This increased resistance induces a rise in temperature – high temperatures deteriorate the connection surface even more. The more deteriorated surface leads to a further increase in contact resistance, and the resulting thermal runaway will cause complete connection failure. Fire, flash-over and explosions become a real risk. Moreover, final circuits should be protected by an arc fault detection device (AFDD) for enhanced fire prevention. Circuits age unevenly and unpredictably, so persistent monitoring and predictive maintenance are key to limiting fire risk. Cloud analytics can help provide asset health analytics to interpret the status and history of your most critical assets, with preventive notifications and 24/7 support. Fire prevention must be a top priority when assessing all the safety and risk-management of a building. In the case of electrical fires, prevention is better than cure. Therefore, establishing the right approach before crisis strikes will be invaluable. Connected solutions across the entire circuit are an effective solution for consultant engineers to defend buildings from the often-underestimated dangers of faulty installation and ageing components. In short, smart electrical fire prevention provides peace of mind for engineers, facility owners and occupants alike. *Stewart Gregory is VP of power products at Schneider Electric