Fires in electrical cabinets: a risk often underestimated

Electrical cabinets are at the heart of the operation of industrial, tertiary, and residential buildings. They distribute energy, protect installations, and ensure the operation of essential equipment. However, they also represent one of the main sources of fire outbreaks in buildings.

A simple overheating, a poor tightening, or an electrical fault can cause a fire capable of interrupting an activity, causing significant material damage, or even putting lives at risk.

Understanding the causes of these fires is the first step to better prevent them.

Why can an electrical cabinet catch fire?

An electrical cabinet concentrates several risk factors:

• a high density of electrical components;

• currents that can sometimes be very high;

• multiple mechanical connections;

• significant thermal dissipation.

Over time, wear or an installation fault can create conditions conducive to a fire outbreak.

The main causes of fire

1. Poor tightenings

This is one of the most frequent causes.

An insufficiently tightened connection creates electrical resistance that leads to gradual overheating.

This phenomenon can go completely unnoticed for several months before causing:

• the melting of insulators;

• an electric arc ;

• the ignition of surrounding materials.

2. Electrical overloads

When a system operates beyond its rated capacity, the conductors and components heat up.

Without appropriate protection, this excessive heat can lead to a fire.

Installation extensions made over the years often increase this risk.

3. Short circuits

A damaged cable, a deteriorated insulator, or an internal fault can cause a short circuit.

The temperatures generated by an electric arc can exceed several thousand degrees in a fraction of a second.

Even if electrical protections trigger quickly, the damage can already be significant.

4. The aging of components

Like any technical equipment, an electrical cabinet ages.

Plastics become more brittle.

Insulators lose their properties.

Connections gradually loosen due to thermal cycles.

Regular maintenance helps identify these signs before they become critical.

5. Dust and contaminants

In industrial environments, electrical cabinets often accumulate :

• dust ;

• fibres ;

• oils ;

• metal shavings ;

• moisture.

These elements can promote overheating or cause electrical faults.

What are the most affected sectors ?

All companies use electrical cabinets, but some sectors present a higher risk :

• manufacturing industry ;

• logistics warehouses ;

• data centres ;

• hospitals ;

• administrative buildings ;

• critical infrastructures ;

• photovoltaic installations ;

• charging networks for electric vehicles.

A failure in these environments can lead to consequences far beyond mere material damage.

The consequences of a fire

A fire in an electrical cabinet does not only destroy the affected panel.

It can cause :

• a complete halt of production ;

• the loss of computer data ;

• the interruption of essential services ;

• damage to neighbouring equipment ;

• significant costs for reinstatement ;

• operational losses for several days, or even several weeks.

In some cases, indirect damages far exceed the cost of the destroyed equipment.

How to prevent these fires ?

Prevention relies on several good practices.

Regular inspection

Periodic checks allow for the detection of :

• overheating ;

• loose connections ;

• damaged components.

The use of thermal cameras is now widely spread to identify hot spots before they become dangerous.

Preventive maintenance

Regular maintenance includes, in particular:

• tightening connections;

• cleaning cabinets;

• replacing worn components;

• checking electrical protections.

These operations significantly reduce the risk of fire.

Suitable design

A properly sized cabinet limits:

• overloads;

• overheating ;

• ventilation faults.

Good design also facilitates maintenance interventions.

Early detection: a determining factor

The earlier a fire starts is detected, the easier it is to limit the damage.

Modern solutions allow for the detection of:

• abnormal temperature rises;

• smoke;

• particles generated by overheating;

• electric arcs.

In some sensitive installations, these systems automatically trigger extinguishing before the fire develops.

Automatic extinguishing systems

For critical electrical cabinets, many companies today choose to install automatic extinguishing systems.

Their goal is simple:

• detect the start of a fire;

• intervene immediately;

• limit damage;

• maintain business continuity.

These systems are particularly used in:

• server rooms;

• industrial installations ;

• control cabinets ;

• energy infrastructures.

Why acting quickly is essential

In an electrical cabinet, a few seconds can be enough for a simple overheating to turn into a fire.

Early intervention often allows for :

• limiting material damage ;

• avoiding a complete shutdown of a production line ;

• reducing operational losses ;

• protecting employees ;

• preserving critical equipment.

The speed of detection and intervention is therefore a key element of any fire protection strategy.

Conclusion

Electrical fires are among the most common risks in industrial and tertiary buildings. Although they are often invisible in their early phases, they can have major consequences on the safety of people and the continuity of operations.

A combination of preventive maintenance, regular monitoring, early detection and, when relevant, automatic extinguishing systems, is the best approach to reduce this risk.

Investing in prevention not only protects equipment: it also helps to maintain operational continuity, limit financial losses, and strengthen the resilience of the business in the face of incidents.