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 – half of all organisations that suffer a fire close within the next five years. It’s a danger organization can’t afford to ignore.
Fires 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.
Who are the key stakeholders?
During the design and implementation phase, the consultant engineer’s role is traditionally to respect and perfect 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 circuit’s fire risk. It’s up to consultant engineers to know their market and privilege solutions that go beyond the minimum to detect and prevent electrical fires.
The smart approach to fire prevention
Prevention is by far the best cure for 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 unrivaled visibility.
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 maximum protection, organisations need 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 centralized 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. Schneider Electric’s ComPact NSX range now offers this earth leakage protection with the same footprint as a classical overload and short-circuit protection. In addition to this protection, the product can 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.
Unprotected electrical switchboards are a hotspot for fires. The equipment is vulnerable to rodent infestation and internal overheating. The IEC 61439-2 Low-voltage switchgear and control gear assemblies –Part 2: Power switchgear and control gear assemblies 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.
Several options are now available to ensure performance and protection during the life of the equipment:
- The improvement of power connections by adding tested and pre-fabricated accessories to the switchboard, such as Schneider Electric’s Linergy system or special terminals on devices that prevent creep like EverLink.
- The use of continuous thermal monitoring for the early detection of faulty connections and temperature alarming. When installed at critical areas of the switchgear, Schneider Electric’s Easergy TH110 and CL110 thermal sensors perform accurate connection and ambient temperature measurements.
- Schneider Electric is developing heat sensors that can detect gas particles emitted by cables to alert operators to dangerously high temperatures before they turn critical.
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. Schneider Electric’s EcoStruxure™ Asset Advisor analyses system and equipment health with conditions-based, pro-active recommendations to schedule maintenance.
When assessing all the risks that face a building or installation, fire should be top of the agenda. However, despite its frequency and many potential causes, preventing it is straightforward with the right approach. By embedding connected solutions across their circuit, a consultant engineer protects against the often unappreciated dangers of faulty installation and ageing components. In this way, smart electrical fire prevention delivers both reliable protection and peace of mind.
What are your thoughts? Continue the discussion on the Electrical Fire Prevention Forum