Identification of the cause of the transformer fire

Transformer is a device that uses the principle of electromagnetic induction to convert alternating current energy into another type of electrical energy with different voltage, current and other parameters. The insulating pads and brackets inside are mostly made of organic combustible materials such as paper, cotton yarn, cloth, wood, etc., and contain a large amount of insulating oil. For example, a 1000-kilowatt transformer uses approximately 0.012 cubic meters of wood, 40 kilograms of paper, and 1 ton of insulating oil. Therefore, its fire hazard is that it is easy to burn. Once a serious overload or short circuit occurs inside the transformer, the flammable insulating materials and insulating oil will be decomposed and burned by high temperature or arc, and produce a large amount of gas, which will sharply increase the pressure inside the transformer, causing the shell to burst, spraying a large amount of oil, and the burning oil flow will further expand the fire hazard and cause large-scale power outages, affecting normal production and life.
In the case of transformer fire cause identification, Zhongke Testing can provide transformer fire cause identification services.

1. Fire caused by insulation damage: The overload operation of the transformer causes the temperature to rise, resulting in poor insulation. Poor stacking of transformer cores or aging of insulation between cores causes increased iron loss and overheating of the transformer.
2. The transformer coil is mechanically damaged or damp, causing short circuit between layers or turns, resulting in high heat. Installation and maintenance reduce insulation. Due to lifting, the insulation of the coil, the porcelain bottle bushing
3, the transformer oil tank, bushings, etc. were accidentally damaged, and oil leakage caused surface dirt to burn when exposed to an open flame.
4, poor contact in transformer wiring, tap changer, etc., causing local overheating, etc.

GB/T 10228-2023 Technical parameters and requirements for dry-type power transformers
GB/T 10241-2020 General technical conditions for resolvers
GB/T 10404-2017 General technical conditions for multi-pole and dual-channel resolvers
GB/T 1094.1-2013 Power transformers Part 1: General provisions
GB/T 1094.11-2022 Power transformers Part 11: Dry-type power transformers
GB/T 1094.12-2013 Power transformers Part 12: Loading guidelines for dry-type power transformers
GB/T 1094.14-2022 Power transformers Part 14: Liquid-immersed power transformer
GB/T using high-temperature insulating materials 1094.15-2020 Power transformer Part 15: Inflatable power transformer
GB/T 1094.16-2013 Power transformer Part 16: Transformer for wind power generation
GB/T 1094.18-2016 Power transformer Part 18: Frequency response measurement
0GB/T 1094.2-2013 Power transformer Part 2: Temperature rise of liquid immersed transformer
1GB/T 1094.4-2005 Power transformer Part 4: Guidelines for lightning impulse and operating impulse tests of power transformers and reactors
2GB/T 1094.5-2008 Power transformers Part 5: Ability to withstand short circuits
3GB/T 1094.6-2011 Power transformers Part 6: Reactors
4GB/T 1094.7-2008 Power Transformers Part 7: Loading Guidelines for Oil-immersed Power Transformers
5

A fire broke out in a canning factory, causing serious losses. After investigating the cause of the fire, it was found that the source of the fire was the transformer in the computer room, so a product quality appraisal was conducted on the transformer.
received the request from the applicant, and the appraisal and analysis expert team conducted research and discussion on the transformer. During the inspection, it was found that the high-voltage winding of the transformer was composed of aluminum, but according to relevant standards, this part of the material should be copper.
The heat resistance of copper is stronger than that of aluminum. If aluminum is used here, there will be safety risks.
Therefore, the cause of the transformer fire was determined to be that some materials used in the transformer did not comply with regulations and could easily cause safety accidents.