Oil-Immersed Transformer Factories: Common Test Items
Oil-immersed transformer factories are key sites for the ongoing development and design of transformers, playing a prominent role in various sectors. New transformer products and functions must be explored and developed by manufacturers. These factories need strong R&D capabilities to continually design and launch new products aligned with market demands—a goal manufacturers must actively pursue. Throughout the development process, continuous testing is essential. Only by persevering through trial and error can factories create new, market-relevant products that better meet people’s needs and ensure the manufacturer’s growth.
Oil-Immersed Transformer Factory
Tests conducted on newly installed oil-immersed transformers are called acceptance tests, which should be performed in accordance with the national standard GB 50150-2006: Electrical Equipment Installation Engineering – Acceptance Test Standards for Electrical Equipment.
Common test items in oil-immersed transformer factories include:
- Insulating oil tests
- Measurement of winding DC resistance together with bushings
- Verification of voltage ratios at all tap positions
- Checking the three-phase connection group and polarity of single-phase transformer leads
- Measurement of insulation resistance for all core-insulated fasteners (where connecting pieces can be detached) and the core (if externally grounded)
- Tests on non-porcelain bushings
- Inspection and testing of on-load tap changers
- Measurement of insulation resistance, absorption ratio, or polarization index of windings together with bushings
- Measurement of dielectric loss tangent (tan δ) of windings together with bushings
- Measurement of DC leakage current of windings together with bushings
- Transformer winding deformation tests
- AC withstand voltage tests on windings together with bushings
- Long-duration induced voltage tests with partial discharge measurements on windings together with bushings
- Switching-on tests at rated voltage
The above items represent common tests regularly conducted in oil-immersed transformer factories. Successfully completing these tests is crucial for production, development, and profitability. Safety must always be the top priority during testing and development.
About Shenzhen SenteBian Electric Equipment Co., Ltd.
A wholly-owned subsidiary of Jishengchang Group, Shenzhen SenteBian Electric Equipment Co., Ltd. was established in 2004. With its own industrial park, the company is an advanced and well-established professional transformer manufacturer, and one of the earliest enterprises in Shenzhen to enter the power transformer manufacturing sector. STB is the transformer brand under Shenzhen SenteBian Electric Equipment Co., Ltd.
