Scrapping a 5000 Kva Oil Transformer Worth the Technician’s Experience
We received feedback from a new Technician who was scrapping out an old 5000 kva oil filled power transformer. It was over 40 years old and hadn’t been in service for 20 years. The primary voltage was 13,800 and the secondary ranged from 120 volts to 600 volts. These voltages made it an unusual transformer, but it was worth more for scrap copper and steel than for reliable reuse. In addition we had limited knowledge of the history of this 5 Mva transformer. The test results were barely acceptable, not good.
The young technician had never seen the inside of an old oil filled power transformer, especially such an unusual power transformer out of a foundry. The things he found interesting, a veteran oil transformer repair technician would take for granted. He was surprised how tightly the core and coils fit inside the tank and how the high and low voltage bushings connected to the transformer. He was amazed by the over 3” diameter round solid copper secondary bushings. He saw how the liquid level gauge and temperature gauge for a 5 Mva oil filled transformer worked. The level gauge inside the power transformer had a simple small rod with a cork at the end. The temperature gauge was just a well extending through the wall of the 5 Mva transformer with a temperature gauge installed in the well. The transformer had a basic tubing and pressure gauge system to add nitrogen or dry air. All very basic stuff, but once he saw all this stuff and the interior of the transformer, these basic things made a lot more sense. Good experience. If a picture is worth a 1000 words, then this simple experience was worth 10,000. Whether a 5000 Kva transformer, 10 Mva, 20 Mva or 50 Mva oil transformer, some of these transformer basics are the same.