An off-circuit tap changing dry-type distribution transformer, also known as an off-load tap changer dry-type distribution transformer, is a specific type of transformer designed for voltage regulation in electrical distribution systems.
Unlike on-load tap changing transformers (OLTC), which can change taps while the transformer is energized and carrying load, off-circuit tap changing transformers require the transformer to be de-energized during tap changes. The transformer is taken offline before adjusting the tap connections.
Here are some key characteristics and features of off-circuit tap changing dry-type distribution transformers:
Oil Immersion Transformer
The oil immersion transformer is a type of power transformer that uses insulating oil as both a coolant and dielectric medium. The core and windings are immersed in the oil, which efficiently dissipates heat and prevents insulation breakdown under high voltages. This transformer are widely used in power distribution and transmission systems due to their reliability, durability, and ability to handle high loads. The oil also helps protect internal components from moisture and oxidation. Common applications include substations, industrial plants, and utility grids, where efficient voltage transformation and energy transfer are critical.
Features
- Device category: Out-door type.
- Low loss, low temperature rising, high reliability, all seaing, and no leakage.
- Iron core adopts high-quality cold-rolled grain-oriented silicon steel sheet, which is seamed by 45 degree full ramp-type to make magnetice flow pass through.
- Continuous type is adopted in coils with an oil guiding structure inside to reduce the temperature rise of coil.
Dry Type Transformer
The dry type transformer adopts high quality material, scientific formula, advanced production and testing equipment, and is produced according to strict technology procedure. The product has the characteristics of high reliability and long service life. It can be used as the upgrading equipment for oil-immersed transformer. The product is suitable for important places or special environment, such as high-rise buildings, commercial centers, airports, tunnels, chemical plants, nuclear power plants and ships, etc.
Features
- Safe and fireproof. It can be operated directly in the load center.
- Small size, light weight, small occupied space, low installation cost.
- High mechanical strength, good thermal stability, high reliability, long service life.
- Low loss, low noise, obvious energy saving effect,and maintenance free.
- Good heat dissipation performance, strong over load capacity, forced air cooling can increase its service capacity.
Technical Parameters
| Rated Capacity (kVA) | Voltage Combination | Connection Group Label | No Load Loss (kW) | Loaded Loss in 100℃ | Short-circuit Resistance (%) | Without Shell Weight (KG) | L × W × H (mm) | |
| High (kV) | Low (kV) | |||||||
| Three Phase Epoxy Resin Casting Dry Transfomer | ||||||||
| 30 | 6 … 11 | 0.4 | Dyn11, Yyn0 | 0.135 | 0.64 | 4 | 820 | 640 × 700 × 600 |
| 30 | 6 … 11 | 0.4 | Dyn11, Yyn0 | 0.19 | 0.64 | 4 | 770 | 590 × 700 × 550 |
| 2000 | 6 … 11 | 0.4 | Dyn11, Yyn0 | 3.32 | 14.5 | 6 | 4300 | 1800 × 1400 × 1700 |
| 50 | 35 … 38.5 | 0.4 | Dyn11, Yyn0 | 0.45 | 1.34 | 6 | 850 | 1500 × 850 × 1500 |
| 5000 | 35 … 38.5 | 0.4 | Dyn11, Yyn0 | 6 | 35 | 6 | 15000 | 3300 × 2100 × 3100 |
| 800 | 35 … 38.5 | 6 | Dyn11, Yyn11 | 2.25 | 8.87 | 6 | 3800 | 2300 × 1700 × 2300 |
| 20000 | 35 … 38.5 | 6 | Dyn11, Yyn11 | 22.9 | 80.6 | 10 | 45000 | 4700 × 2100 × 3700 |
| Three Phase Off-circuit Tap Changing Transformer | ||||||||
| 30 | 6 … 12 | 0.4 | Dyn11, Yyn0 | 0.1 | 0.63 | 4 | 320 | 780 × 480 × 480 |
| 3150 | 6 … 12 | 0.4 | Dyn11, Yyn0 | 2.8 | 25.2 | 6 | 7625 | 2415 × 1775 × 2720 |
| 50 | 20 … 24 | 0.4 | Dyn11, Yyn0 | 0.13 | 0.96 | 5.5 | 765 | 1130 × 900 × 1815 |
| 2500 | 20 … 24 | 0.4 | Dyn11, Yyn0 | 2.34 | 22.22 | 6.6 | 7200 | 2600 × 2030 × 2800 |
| 50 | 35 … 38.5 | 0.4 | Dyn11, Yyn0 | 0.16 | 1.2 | 6.5 | 765 | 1130 × 900 × 1815 |
| 3150 | 35 … 38.5 | 6 | Dyn11, Yyn0 | 2.9 | 27.5 | 6.5 | 9190 | 2730 × 2200 × 2940 |
| Three Phase Oill Immersed Loaded Regulating Power Transfomer | ||||||||
| 1000 | 35 … 38.5 | 6 | Dyn11, Yyn11 | 1.36 | 12.35 | 6.5 | 5060 | 2965 × 2010 × 2530 |
| 31500 | 35 … 38.5 | 6 | Dyn11, Yyn11 | 21.8 | 116 | 10 | 48800 | 5340 × 4215 × 4080 |
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Title: Oil Immersion and Dry Type Transformer
file size: 701.36 KB
published: 16 Dec, 2025
English