De-Energized Tap Changer (DETC) 63 A externally operated tap-changer switch

Established in 2001 with RMB 5 million registered capital, Liaoning Jinli Electric Power Electrical Appliance Co., Ltd is a Chinese national high‑tech enterprise dedicated to R&D, production and sales of diverse transformer tap‑changers. We are recognized as a National Intellectual Property Advantage Enterprise and run a provincial‑level enterprise technology center.

We deliver our products to more than 20 countries and regions worldwide. Our major export items cover off‑circuit linear, disc and plate tap‑changers, plus 10‑35 kV on‑load tap‑changers.

We are a professional manufacturer of general‑purpose transformer tap changers, committed to high‑precision production, strict processing standards and full‑range quality management. Standardized and traceable procedures are applied throughout the whole production cycle, covering incoming raw‑material inspection, CNC machining, assembly and final performance verification.

Our experienced production team adheres to stringent operating specifications to guarantee that all components satisfy requirements for dimensional accuracy and material stability. Core manufacturing procedures consist of automated assembly lines, precision welding and voltage‑withstand tests for tap changers, which are validated by our in‑house test laboratory. Prior to shipment, each finished unit goes through complete functional checks, covering appearance inspection, contact pressure, contact resistance and mechanical endurance testing.

Tap‑changers serve as key voltage‑regulating components for oil‑immersed transformers up to 35 kV, finding broad application in medium‑ and low‑voltage distribution systems.

This series of off‑circuit tap‑changers boasts compact layout, straightforward mechanics and reliable operation. Tap‑position adjustment must be performed only when the transformer is completely de‑energized. Built with high‑strength insulators and wear‑resistant conductive components, these units are well‑suited for oil‑immersed operating conditions, delivering outstanding resistance against aging, vibration and temperature variations. Tap switching is completed via simple manual rotation, resulting in minimal maintenance demand over long‑term operation.

Typical application scenarios include urban‑rural distribution grids, industrial parks, residential areas and small‑scale power plants. By modifying the transformer transformation ratio, the tap‑changer stabilizes output voltage and mitigates voltage deviations arising from load changes and line losses.

The tap-changer switch is designed for use in distribution transformers filled with transformer oil (mineral oil).The switch body, rotor, and shaft are made of a high strength, glass-filled thermoplastic material. The operating shaft is sealed against leakage by high temperature resistant O-Ring.