The type DTW™ de-energized tap changer is a versatile tap-changing switch, which is mounted inside the main transformer compartment attached to the cleat and lead structure of the transformer. The tap changer is a modular design, which allows a wide variety of configurations to suit the needs of the transformer designer.
The tap changer can be applied through BIL of 1,050 kV and has a base current rating of 1,000 A per deck. Each phase of the transformer requires at least one deck module of the tap changer. Using multiple deck modules per phase extends the range of the tap changer to many different winding configurations.
Operation of the tap changer is via a manual gearbox mounted on the exterior surface of the transformers. The switch is suitable for use as a dual voltage switch or as a delta-wye switch with appropriate modifications.
- Maximum rated through-current: 4,000 A (1,000 A per deck)
- Highest rated lightning impulse / power frequency withstand to earth: 1,050 kV / 460 kV
- Lightning impulse / power frequency withstand between adjacent contacts: 400 kV / 130 kV
- Maximum number of operating positions: 6
- The DTW tap changer is extremely versatile due to its modular design
- BIL and current rating cover a broad range of transformer applications