Oil-Immersed Power Transformers
Oil-immersed power transformers are delivered by the manufacturer in a dried condition and, depending on size and weight, in one of the following states:
- Fully assembled and filled with insulating oil;
- Partially disassembled and preserved, filled with oil below the cover, with the remaining space filled with inert gas or dry air;
- Partially disassembled in the tank without oil, pressurized with nitrogen with automatic replenishment.
Sequence of Power Transformer Installation
1. Construction of the foundation and oil containment system;
2. Preparation of the installation site for inspections, heating, and assembly of equipment;
3. Preparation of lifting and handling equipment for transformer installation;
4. Transportation of the transformer to the installation location;
5. Installation of accessory assemblies, including:
- High-voltage (HV), medium-voltage (MV), and low-voltage (LV) bushings
- Cooling system (radiators, pumps, fans)
- Built-in instrument transformers (current and voltage transformers)
- Oil filters and conservator tank
- Buchholz relay and oil level relay
- Expansion tank and oil exhaust pipe
6. Preparation and conditioning of transformer oil, filling system, tanks, and silica gel;
7. Electrical and functional testing of the transformer.
8. Commissioning of the transformer.
