Oil-immersed transformer to mineral oil, synthetic oil as insulation and cooling medium, relying on electromagnetic induction to achieve AC voltage conversion, and does not change the frequency.
| Configuration Feature | Natural Cooling (ONAN) | Forced Air Cooling (ONAF) | Forced Oil & Air Cooling (ODAF) |
| Cooling Principle | Oil natural circulation + Air natural cooling | Oil natural circulation + Air forced cooling | Oil forced circulation + Air forced cooling |
| Capacity Range | 5kVA-500kVA | 250kVA-1500kVA | 1000kVA-2500kVA+ |
| Noise Level | ≤ 55dB | ≤ 65dB | ≤ 75dB |
| Maintenance Cost | Very Low | Low | Medium |
| Energy Consumption | Low | Medium | High |
| Applicable Environment | Normal temperature (0℃-40℃) | Normal-high temperature (0℃-45℃) | High temperature (0℃-55℃) |
| Initial Cost | Low | Medium | High |
Buying Suggestion:
1.Determine capacity and voltage level based on project power demand and power grid conditions;
2.Select cooling method according to ambient temperature and operation load (ONAN for small capacity/normal temperature, ONAF for medium capacity, ODAF for large capacity/high temperature);
3.Consider local standards and certification requirements (e.g., IEC for European markets, IEEE for North American markets);
4.Consult our engineers for free project-specific recommendations, including customized solutions for special scenarios.
Our oil-immersed transformers have a service life of 25-30 years under normal operating conditions. To extend the lifespan: 1) Regularly test the insulating oil (dielectric strength, water content) and replace it if necessary; 2) Inspect the tank for leaks and corrosion; 3) Clean the radiator to ensure smooth heat dissipation; 4) Avoid long-term overload operation. We provide a maintenance guide with detailed operation instructions.
Yes! We fully support customization for voltage level (10kV-220kV), capacity (5kVA-2500kVA+), cooling method (ONAN/ONAF/ODAF), voltage ratio and other specifications. We can also design products to comply with local standards, such as IEC (Europe), IEEE (North America), ANSI (USA), GB (China), DIN (Germany), etc. Just provide your project details and requirements when inquiring.
Delivery time: 25-40 working days for standard models (10kV/35kV, 5kVA-500kVA); 30-60 working days for large-capacity/high-voltage models (110kV/220kV, 1000kVA+); 40-70 working days for customized models. Packaging: Sealed wooden cases with moisture-proof, shock-proof and rust-proof treatment. Transportation: By sea (for bulk orders) or by air (for urgent orders); we cooperate with professional logistics companies to ensure safe delivery, and provide complete shipping documents (bill of lading, commercial invoice, packing list, certification documents).
All our products comply with international standards such as IEC 60076, IEEE C57.12.00 and hold certifications including ISO 9001, CE, UL and CB. For specific markets, we can provide additional certification documents (e.g., CSA for Canada, TÜV for Europe, CCC for China). Our transformers have passed inspections in over 50 countries and are widely recognized by global clients.
Mineral oil is the default option, with advantages of low cost, mature technology and good heat dissipation; suitable for most general scenarios. Synthetic oil has higher dielectric strength, better oxidation resistance and fire resistance, but higher cost; suitable for special environments such as high temperature, high altitude or areas with strict fire safety requirements. We recommend mineral oil for general projects; synthetic oil for special scenarios—our engineers can provide professional advice based on your project conditions.
We implement strict quality control throughout the production process, following the ISO 9001 quality management system:
1.Raw material inspection: All cores, windings, insulating oil and tank materials are sourced from certified suppliers and undergo strict testing (e.g., copper purity test, oil dielectric strength test);
2.Process monitoring: Key processes (winding, core assembly, vacuum oil filling, tank sealing) are supervised by professional technicians and recorded in real time;
3.Finished product testing: Each transformer undergoes comprehensive tests, including no-load loss test, load loss test, insulation resistance test, voltage withstand test, temperature rise test and oil leakage test;
4.Factory inspection: Clients are welcome to visit the factory for pre-shipment inspection; we provide free pick-up, accommodation and technical explanation for large orders.
