1. Ensuring safety when conducting maintenance and repair of transformers
- This is an important thing to be done to avoid labor accidents, minimize incidents and risks for everyone. Some contents need to be done to ensure safety:
- All machinery and equipment must stop operating during maintenance and repair.
- Turn off the power supply before starting the maintenance or repair. Inform people of the time to perform maintenance and repair, so there should be signs like "Repair is not energized"
- Make sure the machine stops working before moving or opening the cover and protective devices
- Keep the machine away from combustible substances and materials.
- Reinstall intact protective devices and lid when maintenance is completed
2. Periodic maintenance of transformers:
- In fact, the repair costs due to sudden equipment damage, damage due to reduced life of the machine, damage to productivity, ... are much greater than the cost of repair. maintenance fee if detected early and preventing failure.
Periodic inspection of the transformer will help us to detect abnormalities of the machine so that we can anticipate failures and failures before they occur by performing regular maintenance carried out monthly. , Every 3 months or 6 months. The target is less, shorter time and can predict the stall must stop.
a. The contents of periodic inspection of transformers:
- Check the surface of insulated porcelain, whether the input ceramic is cracked, cracked, dirty or oiled?
- Check that the cover of the MBA is intact and there is oil leaking.
- Check the color, insulation of oil and oil level in the average vessel, the oil-bearing porcelain, the oil pressure in the pressure-porcelain
- Check the value of the thermometer, manometer
- Check cooling system and oil regeneration equipment continuously
- Check the operation of steam relays, safety valves, anti-explosion glass panes, position of valves between steam relays and auxiliary oil tanks
- Check for signaling devices
- Check cables, busbars, connectors, for heat exposure?
- Check the transformer shelled earthing system, the protection relays
- Is the machine sound normal?
- Check the color of the desiccant
- Check for oil leakage
- Check the status of the machine room: windows, doors, vents, lights, screens, cooling fans.
- Check out fire prevention equipment
b. Periodical minor transformers:
- It is maintenance and repair of transformers that cut electricity but do not remove oil and do not open the gut. Periodic minorities may be performed every 3 months or 6 months depending on the actual working conditions, it is best to perform urea every 3 months
- The Primary School MBA covers the following contents:
- External inspection and minor repairs can be repaired immediately.
- Cleaning the transformer placement, parts of the transformer (radiator wings, chassis, high-voltage insulating low-voltage porcelain, etc.).
- Check and clean all connecting bolts, tighten the nuts.
- Check and replace the roaches that are no longer qualified for use.
- Adding oil to the auxiliary oil tank. Check oil level meter.
- Check the color of the desiccant.
- Check the operation of steam relays, safety valves, signaling devices and cooling systems.
- Check the transformer earthing terminals, protectors and surge protectors, making sure the links are secure from loosening during operation.
c. Periodic overhaul of transformers:
- Machine maintenance, comprehensive repair and inspection, which can include machine drying. The overhaul time depends on performance and machine condition.
An overhaul of an MBA consists of the following:
- Remove the case or unplug the case.
- Check, clean and maintain the coil and magnet, including the pressure regulator.
- Cleaning and maintenance of auxiliary oil tanks, explosion proof pipes, valves, inlet porcelain.
- Repairing cooling devices attached to transformers, desiccators.
- Clean and repaint the cabinet (if needed).
- Check gauges, signaling systems, protection relays.
- Fix devices connected to the MBA.
- Refine the oil or replace it (if necessary).
- Dry the bowel of the machine (if necessary).
- Replace the device.
- Let the machine test and test the results.