Transformer maintenance

This article describes the disassembly and repair of oil-immersed self-cooled, oil-immersed air-cooled, and forced oil-circulation air-cooled transformers, as well as the maintenance of dry-type transformers. Figure 1 shows the oil-immersed self-cooled and oil-immersed air-cooled transformers. Transformer structure.

Transformer maintenance
Figure 1 shows the structure of oil-immersed self-cooling and oil-immersed air-cooled transformers

1- Thermometer: 2- Famous brand: 3- Moisture absorber: 4- Oil level gauge: 5- Explosion-proof tube: 6-Oil conservator (oil pillow); 7- Gas relay: 8- High-pressure casing: 9- Low-pressure casing ; 10- Tap switch: 11- Fuel tank: 12- Iron core: 13- Winding: 14- Drain valve: 15- Trolley: 16- Door 17- Times thermometer; 18- Oil purifier: 19- Breathing apparatus : 20- radiator, 21- grounding bolt; 22- oil sample valve

Preparation work for transformer overhaul

  1. Personnel Organization
    The preparation of personnel, tools and consumables, the specific number of personnel should be determined according to the actual situation
  2. Conduct a comprehensive survey of the main transformer
    Conduct a comprehensive survey of the main transformer:
    ① Reasons for overhaul
    ②Last overhaul report and remaining issues
    ③Recent maintenance report, test report, oil chemical test report
    ④Main transformer 3 years operation record
    ⑤Operation record of on-load tap-changer and no-load tap-changer maintenance test report
    ⑥Model parameters of main transformer, on-load external switch and main accessories, shape and size of main key components
    ⑦Whether there is a renovation project, if so, a renovation plan should be made
    ⑧Understand all existing defects
    ⑨ Formulate “three measures” (safety, technical and quality measures) and construction plan
  3. Technical data preparation
    ①Transformer factory data and maintenance technical data
    ②High-voltage casing maintenance technology and standards
    ③Overhaul technology and standards for on-load external switches and off-excitation tap changers
    ④Cooler, radiator, maintenance technology and standard
    ⑤ Oil pump and fan maintenance technology and standards
    ⑥Oil flow relay, gas relay, pressure relief device, maintenance technology and standard
    ⑦Overhaul process standard for oil conservator and magnetic oil level gauge
    ⑧Oil purifier maintenance process standard
    ⑨Temperature controller maintenance process standard
    ⑩General maintenance process standard for small components of power transformers, including oil drain, butterfly valve, moisture absorber, oil mark, and grounding wire
  4. Preparation of common safety equipment
    ①CO2 fire extinguisher
    ②Work clothes (dedicated)
    ③Ground wire
    ④Insulating shoes and gloves
    ⑤Oil resistant work shoes
    ⑥ Goggles
    ⑦Safety belt
  5. Preparation of common tools and equipment for transformer maintenance
    ①Insulation resistance
    ②AC voltmeter
    ③Clamp-type ammeter
    ⑤Vacuum gauge
    ⑧Electric bridge
    ⑨Vernier caliper
    ⑩ feeler gauge
    ⑪Wire rope
    ⑬Light aluminum alloy ladder
    ⑭Rubber power cord
    ⑮Temporary power switch
    ⑯ Oil filter paper hole punch
    ⑰Various adjustable wrenches
    ⑱ Roller bars for lifting and carrying
    ⑲A variety of screwdrivers
  6. Preparation of main consumable materials
    ①Cotton yarn
    ②Flour (as required)
    ③White cloth tape
    ④ Hacksaw blade
    ⑤ Sponge
    ⑥ Wire
    ⑧Plastic belt
    ⑨Cleaning agent
    ⑩Sealing strip
    ⑫Insulation tape
    ⑬ Welding rod
    ⑭Plastic cloth
    ⑮ oil filter paper
    ⑯Silk cloth
    ⑱ Washing powder
    ⑲602 glue
    ⑳Various gaskets and replacement parts