The working day is over. Employees have left the premises, but some electrical equipment remains switched on. In the distribution board, one connection is overheating. There are no visible signs from the outside, and the power supply is still functioning.
This scenario illustrates why electrical installations require attention even when there is no interruption to operation. The fact that equipment is functioning does not confirm that the installation is safe.
Electrical faults represent a significant cause of fires in buildings and facilities. Their position among the most common causes depends on the type of facility, the period observed, and the method used to record and classify incidents.
For this reason, statistics from other countries should not automatically be applied to Serbia, nor should all electrically caused fires be attributed to fixed electrical installations. The source may also be connecting cables, appliances, and other electrical equipment.
For a company, the key practical question is: Are electrical installations being inspected and deficiencies corrected before they become a source of ignition?
How Can an Electrical Installation Cause a Fire?
A fire can occur when heat or an electric arc ignites insulation or nearby combustible material. A short circuit is not always the cause. Problems can develop gradually over a longer period of use.
Overloading. Connecting additional loads without checking the capacity of the installation can lead to excessive heating. Temporary solutions that become permanent are particularly problematic, including extension cords, power strips, and unverified modifications or additions.
Poor connections. Loose or corroded contacts can experience localised overheating due to increased contact resistance. Critical points may include connections inside distribution boards, sockets, and junction boxes.
Damaged insulation and electric arcing. Wear, crushing, and other forms of conductor damage can create conditions for faults and the development of an electric arc. The heat generated by an arc can ignite surrounding materials.
Inappropriate modifications. Changes made without professional verification and prior design may compromise the coordination between conductors, loads, and protective devices.
Replacing a protective device with one having a higher rated current simply to prevent it from tripping can leave the installation inadequately protected.
The risk increases further when cardboard, paper, or other combustible materials are stored near electrical equipment. Good housekeeping and proper storage therefore have a direct preventive role.
Why Might a Circuit Breaker Not Trip?
“If there were a problem, the circuit breaker would switch off the power.”
This assumption can create a false sense of security.
Fuses and circuit breakers have specific protective functions and operating characteristics. Not every poor connection, localised overheating, or electric arc is accompanied by a current level that will cause them to operate in time.
A residual current device (RCD), commonly referred to as an “FID” device, is also not universal protection against all electrically caused fires. For example, a series arc fault can occur without sufficient leakage current to earth to activate an RCD.
AFDDs (Arc Fault Detection Devices) are available for detecting certain types of arc faults, and their use may be considered when professionally selecting protection for a specific circuit.
Protective devices, installation quality, and maintenance should therefore be considered as an integrated system.
Warning Signs That Should Not Be Ignored
The USFA, in its recommendations for workplaces, specifically emphasises checking damaged and overloaded outlets, cables, and connections, as well as keeping combustible materials away from electrical equipment.
The following signs require reporting and professional inspection in particular:
- a smell of burning or heated plastic;
- darkening, deformation, or melting marks on sockets or connections;
- crackling, sparking, or unusual sounds;
- repeated tripping of protective devices;
- visibly damaged cables and loose connections;
- repeated flickering of lights or interruptions of operation with no known cause.
Employees should know whom to notify when they identify a problem and how further use of potentially unsafe equipment is prevented.
They should not open distribution boards, touch suspicious components to check their temperature, or attempt improvised repairs.
If smoke or fire occurs, the priority is to alert people in the area, evacuate the premises, and contact the fire and rescue service.
What Do Professional Inspection and Testing Provide?
A visual inspection can identify some problems, but it is not sufficient for a comprehensive assessment of an electrical installation. The scope of a professional inspection is determined by the type of installation, operating conditions, and applicable requirements.
An assessment should connect the actual condition of the installation with documentation, modifications that have been made, actual loads, and the results of appropriate measurements and tests.
Particular attention should be given to sections of the installation that have been modified subsequently or that supply equipment critical to business continuity.
For management, the quality of the information provided in the final report is also important: where the deficiency is located, what risk it represents, what action is required, and under what conditions the equipment may continue to be used until remediation is completed.
The value of an inspection is realised when a finding is translated into a specific and verified corrective measure.
Where Does Thermography Help and What Are Its Limitations?
Thermographic inspection can indicate abnormal heating of electrical connections and components. It is particularly useful in preventive maintenance and monitoring changes over time.
The result depends on the load at the time of imaging, accessibility of the inspection point, surface characteristics, and professional interpretation.
An installation operating under a light load during the inspection may not show the heating that occurs under peak operating conditions. A similar thermal pattern may also have several possible causes, meaning that the finding requires further verification.
Thermography complements other inspections and tests; it does not replace them. Inspecting energised equipment requires qualified personnel and appropriate safety measures.
New Equipment Requires Verification of the Existing Power Supply
Consider a production facility where the electrical installation was originally designed for a certain number of loads.
Over the years, air-conditioning units, heating equipment, and new production machinery have been added. The installation has been expanded, but the documentation and load assessment have not kept pace with these changes.
This is an illustrative example of an organisational gap: equipment procurement and infrastructure management are treated separately.
Before connecting a new load, a qualified professional should assess the power supply conditions and determine whether modifications to the installation or protective measures are required.
This verification is particularly important when increasing capacity, changing the purpose of a space, or carrying out reconstruction works.
How Should a Company Organise Prevention?
A practical prevention plan should include five interconnected steps:
- Establish the actual condition. Collect documentation, previous inspection findings, fault records, and information on modifications that have been made.
- Set priorities. Identify sections of the installation whose failure could endanger people, cause ignition, or interrupt a critical process.
- Carry out professional inspections. Plan inspections, testing, and, where justified, thermographic surveys in accordance with applicable requirements and conditions of use.
- Correct deficiencies. For every finding, assign a responsible person, deadline, and necessary temporary measures. Unsafe equipment should not remain in operation simply because remediation has been scheduled.
- Verify the result. Document completed works, carry out the necessary post-remediation checks, and update the documentation with the involvement of an authorised company qualified to inspect electrical installations.
Protecting People and Business Continuity
A fire in a distribution board can have consequences far beyond the equipment itself: injuries, evacuation, production downtime, damage to goods, and failure to meet customer commitments.
Electrical installation maintenance should therefore be integrated with fire protection, occupational safety and health, and business continuity planning.
The most important outcome of an inspection is that an identified hazard is eliminated before it puts people or the facility at risk.