Oil Immersed Transformers
250 kVA to 16000 kVA, ONAN cooled, hermetically sealed or with a conservator. The standard choice for outdoor substations, utility distribution and heavy industrial loads.
Technical specification
| Power Rating | 250 – 16000 kVA |
|---|---|
| Primary Voltage | 3.3 / 6 / 10 / 11 / 13.2 / 13.8 / 15 / 20 / 22 / 33 / 34.5 / 35 kV class |
| Secondary Voltage | 480/277 V, 400/230 V, 380/220 V, or customized |
| Phase | Three-phase |
| Cooling Type | ONAN |
| Core Material | High-efficiency (CRGO) silicon steel |
| Connection Group | Dyn11, Yyn0, Dyn5 |
| Winding Material | Copper / Aluminium |
| Frequency | 50 / 60 Hz |
| Insulation | Mineral oil |
| Tap Changer | ± 2 × 2.5% Off-Circuit Tap Changer (OCTC) |
| Short-circuit impedance | 4 – 6% |
| Temperature Rise | 60 – 65 °C |
| Noise Level | ≤ 60 dB at 1 meter |
| Enclosure | Hermetically sealed steel tank, weatherproof for indoor and outdoor use |
| Altitude | ≤ 1,000 m or customized |
| Ambient Temperature Range | -30 °C to +50 °C |
| Accessories | Conservator tank, oil level indicator, gas relay, pressure relief valve, etc. |
| Standards Compliance | IEC 60076, IEEE C57, ANSI C57 |
| Applications | Commercial and institutional buildings, industrial facilities, oil & gas, solar and wind energy, utility grid connections, data centers, and coastal islands and high-altitude regions. |
| Transport & Installation | Lifting lugs, skid base, galvanized fittings |
| Warranty | Two years |
| Delivery Time | Typically 30 days, depending on quantity |
| Min. order quantity | ≥ 1 set |
Typical ratings
250 · 400 · 630 · 800 · 1000 · 1250 · 1600 · 2000 · 2500 · 3150 kVA and above
Other ratings are built to order. If your rating is not on this list, send it anyway.
How it is built
- Core: cold-rolled grain-oriented silicon steel, mitred step-lap, clamped to hold noise down.
- Winding: copper or aluminium, wound in-house.
- Tank: corrugated wall or radiator, pressure tested before filling.
- Drying: vacuum drying in our own plant, then vacuum oil filling.
- Sealing: hermetically sealed, or conservator with a silica-gel breather.
Options and accessories
Tap changer
Off-circuit ±2 × 2.5%, or an on-load tap changer.
Winding material
Copper or aluminium, to the loss figures you need to meet.
Protection
Pressure relief device, gas relay, oil level and temperature indicators.
Terminations
HV cable box or bushings, LV busbar or cable box.
Monitoring
Winding temperature indicator with alarm and trip contacts.
Finish
Standard industrial paint, or the colour your utility specifies.
Standards and testing
- Routine tests on every unit: winding resistance, ratio and vector group, insulation resistance, impedance voltage, separate-source and induced voltage withstand.
- Type tests on request: temperature rise, lightning impulse, short-circuit withstand.
- Designed and tested to IEC 60076. IEEE and ANSI practice applied for 60 Hz designs.
- A test report in English goes out with every transformer.
Browse products in this range
Every model below is built to order in the same Baoding factory. Open a sub-category to see models, ratings and specification tables.
Frequently asked questions
Send us the specification
Rating, primary and secondary voltage, frequency, quantity and the application. We answer within one working day.