Electrical Power Transformer we can see everywhere at our neighboring street. It has a important roll to our daily life. Our home equipments can operate with the high voltage that we generate in Power Station. This is the only equipments in substation that step down the voltage level from high voltage. In this post we will learn, “Transformer – How It’s Made?”
Transformer- How It’s Made:
Generally transformer manufacturer start to make a transformer by two materials. First one is paper and it always coated by the epoxy glue. Worker tape this paper with a wooden block. Second material is 3mm thickness aluminum strip. These metal strips withstand the heat and high voltage current produces. Then worker secure both material with the same wooden block and rotated it. By this rotation paper and metal strip become together.
After that an aluminum Bus Bar called the low voltage lead and it send the low voltage current out of the transformer. Then worker fold the leads and send it to another rotating block for further wrapping. The insulation paper has epoxy glue on its both side and it is essential for next wrapping. Because this epoxy glue will melt during baking section and make a bond with several components.
On the new block a worker tapes on more epoxy glue insulating paper. Then they tapes epoxy coated copper wire. Worker roll on a layer of copper wire covering the insulating paper. They repeat the same process again to forming a second layer of copper wire. After that worker joint the high voltage leads with the copper wire by soldering. Then he rolls another layer of copper wire.
After that worker attached what’s called leads wire out. The wire that will protrude from the power transformer cylinder and the vinyl coated wires that will two different voltages out of the transformer. Till now they are making the coil for a transformer. It also has another important parts called core. Worker use electrical steel to make its core. After that they secure the core and coil by metal strapping. This strapping will keep these two parts together in transformer tank.
After strapping worker send complete assembly to the oven. Oven temperatures maintain 135 degree calculus. It will bake for next eight hour for removing any trace of humidity and improve the insulation. This baking also fused the epoxy glue with insulation paper, aluminum strips and the copper wire. Then complete assembly goes into the transformer tank. You can say it is the outer shell of a transformer.
Then worker attached the rubber gasket with the round edge of tank by hammer. Because this tank need to be complete water resistance. Then the bolt the grounding wire with the tank. After that they insert three thermo plastic bushings. Then they connect the low voltage leads with the thermo plastic bushings. After that they bolt the bushings to the tank. They also add a transformer oil filled guide with the side of tank. Then they position automated transformer oil filled machine at the top of the tank. This machine will create the vacuum pressure to remove air during oil filling.
This oil is use for transformer insulating and cooling purpose. They also attached an internal fault detector to alert the maintenance crews if there is any short circuit. Then worker insert a leads wire through the incoming thermo plastic bushings and secure it in place. Then they attached the high voltage cable connector with it. After that they bolt the tank cover. Now before transformer goes to service it need to pass the testing department. They test each unit of transformer by simulation with actual power. When it pass then it’s ready to hang with your nearby utility pole.