The fire safety measures for dry-type transformers mainly include the following aspects:

1. Installation location and environment

• Reasonable layout
  • Dry-type transformers should be installed in a separate transformer room, and must maintain a sufficient safety distance from flammable and explosive materials. For example, in factories where a large number of flammable chemicals are stored, the transformer room should be located away from the chemical warehouse, generally requiring a distance of no less than the specified fire protection distance.
  • The installation location should facilitate ventilation and heat dissipation, while avoiding installation in densely populated areas or above evacuation routes to prevent potential fire hazards from harming personnel.
• Environmental control
  • The installation environment of the transformer should be kept dry to avoid humidity affecting the insulation performance of the transformer. For places with high humidity, such as underground substations, dehumidifying equipment can be installed to control the environmental humidity within an appropriate range (generally, relative humidity should not exceed 70%).
  • Prevent the transformer from being eroded by pollutants such as dust and corrosive gases. In industrial sites with dust pollution, such as cement plants and coal mines, air filtration devices should be installed to prevent dust from entering the transformer.

2. Temperature monitoring and control

• Temperature monitoring system
  • Equipped with a complete temperature detection device, such as platinum resistance temperature sensors, to monitor the temperature of the transformer windings and core in real time. These sensors should be accurate and reliable, capable of timely feedback on temperature changes.
  • The temperature monitoring system should have an alarm function, which can issue audible and visual alarm signals in a timely manner when the temperature exceeds the set safety threshold (for example, for transformers with F-class insulation, when the winding temperature reaches around 155°C), reminding staff to take action.
• Cooling system maintenance
  • For dry-type transformers that use forced air cooling, the operation of the cooling fan should be checked regularly. Ensure that the fan motor operates normally, the blades are undamaged, and the ventilation ducts are not blocked.
  • Regularly clean the dust and debris from the cooling system's filter and radiator surfaces to ensure good cooling performance. For example, in areas with significant sand and dust, it may be necessary to clean the cooling system once a month.

3. Overload protection

• Reasonable configuration of protection devices
  • Install appropriate overload protection devices, such as thermal relays and overcurrent relays. These protection devices should be correctly parameterized based on the rated capacity and load characteristics of the transformer.
  • The protection devices should be reliably connected to the transformer control system, and when an overload occurs, they can quickly cut off the power supply to prevent the transformer from overheating due to prolonged overload operation, which could lead to a fire.
• Load management
  • Plan and manage the load of the transformer reasonably to avoid prolonged overload situations. Use an electric power monitoring system to monitor the load rate of the transformer in real time, and when the load rate approaches the overload threshold, timely adjust the load distribution or take power limitation measures.

4. Insulation maintenance

• Regular insulation testing
  • Regularly use insulation resistance testers and other equipment to test the insulation resistance of the transformer. Generally, the insulation resistance should not be lower than the specified value (e.g., ≥2MΩ). If a decrease in insulation resistance is found, the cause should be identified and addressed promptly.
  • Conduct tests for power factor and other insulation performance tests to comprehensively assess the insulation condition of the transformer. For transformers that have been in operation for a long time, a comprehensive insulation performance test should be conducted at least once a year.
• Prevent insulation damage
  • Avoid mechanical damage to the transformer; handle with care during transportation, installation, and maintenance to prevent collisions that could cause the insulation layer to crack.
  • Prevent overvoltage from damaging the transformer's insulation by installing appropriate surge protectors and other overvoltage protection devices to limit the damage from lightning overvoltage and operational overvoltage.

5. Firefighting facilities configuration

• Fire extinguishing equipment configuration
  • Appropriate fire extinguishing equipment, such as dry powder extinguishers and carbon dioxide extinguishers, should be installed in and around the transformer room. The quantity and location of extinguishers should comply with fire safety regulations, and the effectiveness and pressure of the extinguishers should be checked regularly.
  • For large and important dry-type transformer locations, consider installing an automatic fire extinguishing system, such as a FM-200 gas extinguishing system. This system can automatically activate in the early stages of a fire, quickly extinguishing the fire and reducing fire losses.
• Fire separation measures
  • Firewalls should be used to separate the transformer room from other rooms, and the fire resistance rating of the firewall should meet fire safety standards. The firewall should ensure there are no holes or gaps to prevent the spread of fire.
  • The door of the transformer room should be a Class A fire door and should remain closed to prevent the spread of fire and smoke to other areas.