Fire Detection in Electrical Switchboards & Rooms

According to the National Fire Protection Association ("NFPA") in the United States, Electrical distribution and lighting equipment is the leading cause of structure fires in industrial properties, accounting for 24% of all firesRichard Campbell, NFPA Research, Fires in Industrial and Manufacturing Properties, March 2018, p5. Of these fires 55% of the properties involved direct property damage.

Detecting a fire at its very early (incipient) stage is critical to mitigating significant property and equipment damage.

There are numerous causes of an electrcial fire in a switchboard or rooms carrying power distribution, substations, electrical equipment or industrial controls. Common causes include;

• Undersized or overloaded conductors or poor quality wires; 
• Loose conductors or connections;
• Components touching or close contact leading to an electric arc between energised electrical components;
• Excessive current flow/surges;
• Component failure.

One of the common preventative maintenance actions that may be useful to detect the presence of conditions prior to a fire is undertaking thermal imaging of an electrical switchboard on a periodic basis.  Thermal imaging is can provide information showing components or conductors operating at excessively high temperatures or high resistance joints.

The problem with this method is that these inspections occur are periodic (planned) intervals and are not active fire detection methods.

Detecting the early presence of a fire may be necessary (even critical) for some buildings and applications.  Modern equipment such as life support systems, communication systems, building or process automation systems and building amenities require special attention to maintain continuity.

For the sake of this article, continuity is a term that describes the ongoing and reliable operation of services to ensure these systems are working and will continue to work.

Continuity is critical for life safety, and ongoing business operations.

When I think of continuity in this context the two first things that come to mind are hospital operating theatres and access to the internet. But there are many more systems that as a modern society we rely on every day such as the production of vaccines, communications, access to building materials, manufacturing and food processing.

Imagine the deleterious effect if just one of these critical items of equipment or business processes was interrupted by the loss of power due to a fire in an electrical switchboard, substation, telecommunications system or control system.

The National Construction Code (“NCC”) or (“the Building Code”) provides a framework for the construction of buildings and structures in Australia.  The Building Code generally provides guidance on fire safety from a life safety perspective instead of asset protection, except where asset protection is necessary for life safety.

From a fire safety perspective, asset protection has to do with the protection of an asset from fire to minimise or eliminate loss in the event of a fire related to that asset. It generally has very little to do with life safety.

Examples of asset protection include installing a fire detection and fire suppression system within a computer room, specialised (and expensive) medical equipment such as a Magnetic Resonance Imager (“MRI”) and items of machinery or vehicles where a loss of production could cause significant damage or loss.

Because the Building Code concerns itself with life safety rather than asset protection, it is typically an insurance or commercial decision to augment building fire safety systems with specialised fire detection and fire protection systems.