Why Is an Automatic Fire Detection and Extinguishing System Mandatory for Oil-Type Transformers?

Oil-filled transformers represent one of the most critical fire hazards in the energy sector, carrying a high risk of combustion. The mineral oil or synthetic ester contained within serves both insulating and cooling functions; however, in the event of an internal fault, arcing, or overheating, this fluid can easily ignite, spiraling out of control within seconds and potentially causing an explosion. Consequently, installing an automatic fire detection and suppression system within the transformer enclosure is a mandatory requirement under numerous regulations and technical specifications.

Why Is the Fire Risk So High in Oil-Filled Transformers?

Transformer oil vaporizes rapidly, creating flammable gas mixtures. An arc resulting from an internal fault can ignite the oil and cause a pressure buildup within the transformer tank, leading to structural failure or even an explosion. A fire originating in an enclosed transformer room can spread within minutes to adjacent areas, cable galleries, and the building structure itself. Conventional smoke detectors and handheld extinguishers are inadequate for tackling a fire that escalates this quickly—and human intervention often comes too late.

...remains.

Regulatory Overview

The "Regulation on the Fire Protection of Buildings"—the primary regulation in Turkey regarding fire safety in structures—classifies transformer and generator rooms as specific hazard areas and mandates special structural and fire suppression measures for them. Depending on the oil quantity and transformer power rating, the installation of automatic detection and automatic fire suppression systems may be required in these areas.

In addition:

• Standard technical specifications issued by distribution companies and TEDAŞ (Turkish Electricity Distribution Corporation) detail the comprehensive safety equipment required for transformer substations and transformer rooms.
• International best practice guidelines (such as NFPA 850 for power plants and high-voltage facilities, and electrical system standards like IEC 61936-1) mandate or recommend fixed fire suppression systems for oil-filled transformers.
• Insurance companies may require automatic fire suppression systems—particularly in industrial facilities—as a condition for policy coverage and premium determination; the absence of such a system can significantly impact compensation processes following fire-related damage.

Note: Regulatory article numbers and oil/power threshold values ​​are subject to change over time.

It is recommended to consult the current official text of the relevant regulation and the technical specifications of the system provider regarding the project design phase.

Which Transformers Fall Under This Scope?

• Oil-filled transformers located indoors (enclosed transformer rooms/cubicles) or adjacent to a building
• Power transformers exceeding a specific power rating (kVA)
• Transformer rooms in facilities with continuous energy needs or high human occupancy, such as hospitals, Organized Industrial Zones (OIZs), shopping malls, data centers, power plants, and factories
• Due to their oil content, oil-filled transformers—as opposed to dry-type transformers—are the primary focus of this subject

What Happens If the System Is Not Installed?

The absence of an automatic detection/extinguishing system can lead to obstacles in obtaining occupancy permits and fire department clearance, non-compliance findings during inspections, and the rejection of insurance claims; in a worst-case scenario, it can result in significant losses and high financial damage caused by prolonged power outages. Transformer-related incidents typically entail production or service interruptions and repair processes lasting hours.

Key System Components

An automatic detection and suppression system generally consists of the following components: heat, flame, and smoke detectors; a suppression control panel; and generators or nozzles that discharge the extinguishing agent. You can find detailed information regarding system operation records, applicable standards, and certification requirements on our pages: What is a Potassium-Based Aerosol Gas Fire Suppression System? and On Which Standards Is the Technical Specification Based?

Unfortunately, for Oil-Type Transformers...