Fire Safety Science

The Hidden Danger: Understanding Transformer Fires and Clean Agent Protection

March 19, 2024 | Fire Safety Science 

The Hidden Danger: Understanding Transformer Fires and Clean Agent Protection

Transformers tirelessly convert voltage levels to deliver power to our homes and businesses. While essential, these components also carry a potential fire risk. Let’s delve deeper into transformer fires, their causes, consequences, and how clean agent fire suppression systems can mitigate these risks.


What are Transformer Fires?

Transformer fires are uncontrolled combustions that occur within or around a transformer unit. These fires involve the flammable insulating oil present in most transformers, typically mineral oil. This oil plays a crucial role in:

  • Cooling: Dissipating heat generated during operation.
  • Insulation: Preventing electrical current from leaking between different voltage levels within the transformer.
  • Arc Suppression: Quenching sparks that might occur during normal operation.

Unfortunately, the same properties that make mineral oil beneficial also introduce a fire hazard.


How and Why Do Transformer Fires Happen?

While uncommon, transformer fires can erupt from several factors:

  • Electrical Faults: Internal short circuits or ground faults due to deteriorating insulation or manufacturing defects can generate excessive heat, igniting the surrounding oil.
  • Overloading: Operating a transformer beyond its rated capacity can lead to overheating and eventual fire. This can occur due to increased demand or malfunctioning cooling systems.
  • Mechanical Failures: Internal component breakdowns, such as bearing failures or loose connections, can cause excessive friction and sparking, triggering a fire.
  • External Factors: Lightning strikes or external fires can also damage a transformer and ignite the insulating oil.

The Devastating Consequences:

When a transformer fire erupts, it can have serious consequences:

  • Intense Heat: Transformer fires burn fiercely due to the presence of the oil and combustible materials like paper insulation within the unit. The intense heat can damage surrounding equipment and pose a significant safety risk.
  • Explosions: Rapid pressure buildup within the transformer due to the fire can lead to violent explosions, further escalating the damage and potential injuries.
  • Power Outages: Transformer failure can disrupt power supplies to homes, businesses, and critical infrastructure, causing widespread inconvenience and economic disruptions.
  • Environmental Impact: Transformer fires can release harmful pollutants, including polychlorinated biphenyls (PCBs) in older transformers, posing environmental hazards.

Recent Statistics:

While transformer fires are not frequent, they are a real concern:

  • Probability: Industry reports estimate the average chance of a serious transformer fire is between 0.06% and 0.1% per year of service
  • Impact on Transformers: Over their lifespan, 2% to 4% of transformers can be expected to experience a fire incident.

Clean Agent Fire Suppression Systems: A Safeguarding Solution

Thankfully, with proper measures, transformer fires can be prevented and mitigated. Clean agent fire suppression systems offer a reliable and effective solution:

  • Fast and Efficient Extinguishing: Clean agents such as our DAR (Direct Agent Release) or SAR (Secondary Agent Release) system extinguish fires quickly and effectively by displacing oxygen or interrupting the chemical chain reaction. This rapid response minimizes damage and potential escalation.
  • Safe and Environmentally Friendly: Modern clean agents like FK-5-1-12 leave no harmful residue, unlike traditional fire suppression methods that can cause environmental damage.
  • Targeted Protection: Micro-suppression systems utilizing clean agents can be strategically placed near transformers. These systems are pre-programmed to detect rapid temperature increases and trigger a response through a heat sensing tube or smoke activated device in order to suppress the fire at its early stage.


Transformer fires, though infrequent, present a significant risk. Understanding the causes, consequences, and implementing preventive measures like clean agent fire suppression systems are crucial for safeguarding our electrical infrastructure and ensuring the continued safe and reliable delivery of power

We specialize in the production of automatic fire suppression systems designed to ensure the safety of various assets and industries. Our commitment to protection is at the core of our solutions, providing a reliable guarantee for safeguarding your assets.

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