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With each new day bringing in the latest tech, there has been an explosion of electrical appliances in our homes. Add rising temperatures to the mix, and the already high demand for stable electricity is further pushed exponentially. Amid all this, your local electric substation is overtaxed and faces possible glitches. This is where electrical transformers come in.
It forms the very backbone of an electric substation by ensuring that power is transferred between circuits with no change in frequency. Electrical transformers are responsible for the smooth flow of electric power to a particular region. This vital piece of equipment, thus, needs proper care and regular maintenance.
Maintenances can be broadly split into two types- preventative and required. Simply put, the first is done as a regular way to keep the transformer in good health, whereas the latter is done to correct a fault in the system and is an emergency response. Periodically checking the transformer is an excellent way to avoid a breakdown in the system.
Insulation Is Key
Some parts of the transformer require a daily look as they are vital to its function. The oil in the transformer serves as electrical insulation and must remain dry and clean. Its primary function is to transfer the transformer’s active parts into coolers. If there is any moisture or leakage, it will not insulate properly.
Similarly, the silica gel breather typically needs to be changed in the electrical transformers if more than two-thirds of the gel has changed colour from blue to red. A silica gel breather is a way to filter the air from moisture.
Once a month, the silica gel breather also needs to be checked for transformer oil. If the oil level in it falls short inside the cup, it is advisable to bring it up to the specified level. The transformer oil should also be checked regularly since it is key to maintaining insulation.
Typically, the oil should be checked only after 12 months of being filled. If it is a sealed transformer, then you should contact the manufacturer before taking regular samples. A hermetically sealed transformer is usually less exposed to moisture.
Electrical transformers are a combination of many small parts. Bushing, an electrical insulator, is one part that needs to be checked annually for cracked. Since the transformer deals with electricity, its cooling system is at the heart of its function. The pumps and the cooling mechanism’s fans should be checked yearly to avoid any emergency shutdown due to high temperatures.
Insulation is key to a transformer as its core function is to relay high amounts of electricity. All components that help maintain it, like the oil, must be checked yearly. To check the oil, take a sample to check for dielectric strength and moisture content. If either does not fall within the specified limit, consider changing the oil.
Additional Resource: How Accurate Are Magnetometers/Gaussmeters?
Maintenance When The Transformer Is Energized
Only a limited number of inspections should be carried on when the electrical transformers are in use. One can check for cracks, leakages, discernible temperature spike in joints, or bushings using a heat-sensitive camera. Oil samples from the conservator type transformers can also be taken while the transformer is still in operation. However, safety precautions and careful supervision is required to perform the checks as the transformer has not been shut down.
Some fixes need the transformer to be shut down to ensure safety. Some fixes to consider are welding joints, blocking leaks, cleaning contaminated surfaces like bushings. One can also inspect the functionality of the other parts like tap changer, gas relay, and winding support to detect and prevent contamination.
The health of electrical transformers will significantly depend on the consistency of care. Since the equipment has many parts, it may not be feasible or even advisable to check them regularly. However, regular inspection allows you to catch any problems before they hamper the workings of the equipment.
Despite all the care, there may be times when there is a glitch in the system. At the very outset, check if it is the transformer or another part of the system and take immediate steps. The type of solution you take will also depend on the type of transformers, dry, or oil-immersed, which have different sets of solutions.
Electrical transformers can be tricky to maintain and have no room for error due to the nature of their function. It is recommended that you consider hiring professionals before performing any checks on the equipment and take all necessary safety precautions. Skilled technicians can help ensure maintenance and installation safety and offer guidance on operating such critical electrical systems!