Product Overview
Robust Oil-Immersed Power Transformer from Subian Electric’s Xuzhou Factory
The 35kV oil-immersed power transformer is a durable and efficient solution for power distribution in medium voltage networks and for switching voltage levels and transmitting electric energy. With the improvements in design of its structure, materials and manufacturing process, it is able to withstand short circuits, have low losses and to work quietly.
Applications & circuit protection
This transformer is being used in regional distribution systems, industrial supply systems and utilities in which reliable high-power transformation is necessary.
- Distribution substations: transformation from 35kV to MV/LV levels.
- Industrial parks: steady energy for producers.
- Mines and factories: reliable energy for heavy industry.
- Utility networks: network expansion and modernization.
Construction & operating reliability
The strong construction of the tank with the use of steel strap clamps, high-quality insulating oil and a reliable core and coil design gives low losses and reliable performance.
- ONAN cooling enables easy and reliable performance.
- Efficiency under load ≥99%.
- Good short circuit withstand capacity.
- Very quiet operation (≤65 dB).
- Variable secondary voltage from 0.4kV to 10kV.
Technical Parameter
| Parameter | Value |
| Rated capacity range | 50-2500 kVA |
| Voltage combination (HV) | 35 / 38.5 kV |
| Tap range | ±5% / ±2×2.5% |
| Voltage (LV) | 0.4 kV |
| Connection group | Yyn0 / Dyn11 |
| No-load loss (typical range) | 130-3200 W |
| Load loss (typical range) | 1200-33000 W |
| No-load current (typical range) | 0.5-1.3% |
| Short-circuit impedance | 6.5% |
| Rated voltage | 35 kV (primary), 0.4–10 kV (secondary) |
| Power rating | 500 – 20,000 kVA |
| Rated frequency | 50/60 Hz |
| Efficiency | ≥99% at rated load |
| Insulation class | A (temperature rise ≤65K) |
| Cooling method | ONAN |
| Lightning impulse withstand | 170 kV |
| Noise level | ≤65 dB (full load) |
| Standard | IEC 60076 / GB 1094 |
Transformer Price Guide & Factory Pricing
Purchasing directly from the producer eliminates intermediary profits. The price quoted by our factory for the Oil-Immersed Power Transformer depends on its rated capacity, type of material (copper or aluminum winding and silicon steel/amorphous core) as well as order amount. In order to receive a quotation, send us data regarding the capacity, voltage, quantity, and destination port of your order.
- Transparent factory pricing with no hidden charges
- Volume discounts for container and project orders
- Free technical selection support with every quotation
How to Connect This Transformer
Before you are able to charge the oil-filled transformer, confirm that the tap position is correct and corresponds to the supply voltage, while also confirming that the connection group is adequate for your system. High-voltage bushings are connected to the supply side while the low-voltage is connected to the load side. The earth terminals are connected to the earth system according to local requirements.
- Make sure that the tap position is correct
- Connect the high-voltage bushings to the supply side
- Connect the earth terminal according to local regulations
This Transformer vs. Alternative Ratings
Compare typical configurations to select the correct rating:
| Item | This Product | Smaller / Larger Option |
| Capacity | As specified on this page | Lower or higher kVA available |
| Voltage | As specified | Other primary voltages available |
| Impedance | Per standard / custom | Adjusted to network requirements |
| Cooling | ONAN or AN/AF per type | Forced cooling option on request |
| Application | Distribution / power | Industrial, renewable or utility |
Export Markets & Country Compatibility
We provide Oil-Immersed Power Transformer to dealers, utilities, and project customers all over Asia, Africa, the Middle East, Latin America, and Europe. Before commencing production for any destination, we check what voltage, frequency, connection group, and certification are required.
Transformer Dimensions, Weight & Packing
The size and weight mainly depend on the capacity, voltage, and number of phases. Typical size estimates for distribution transformers are: oil-immersed transformers rated at about 100 kVA are approximately 1000-1200 mm in length, 500-700 mm in width, and 1100-1400 mm in height with a shipping weight of about 600-900 kg; larger rating transformers have similar proportions. Actual drawings of sizes and shipping weights are provided with the order, and the transformer is designed for land or lay transportation.
- The size drawing is agreed before manufacturing
- Packing is done according to export standards, lifting points are marked
- The client needs to notify the transportation method and port before dispatch.
Standards & certifications
Constructed according to IEC 60076 and GB 1094, this transformer comes with type-test documentation to facilitate project approval.
- Design Standard: IEC 60076 / GB 1094.
- Availability of both type-test and routine-test documentation.
- The transformer’s design achieves maximum efficiency and minimum losses.
- Certificate and approval documents.
OEM & B2B supply support
Subian Electric, which is a major manufacturer of power equipment, provides essential power transformer support services to utility companies, engineering, procurement, and construction (EPC) contractors, and distributors.
For information on capacity, voltage and tap changes, please let us know your requirements.
- Sample and engineering drawings provided.
- Flexibility in quantity order.
- OEM and ODM support.
- Custom printing and packing of goods available.
- Technical documentation and certification support.
Frequently Asked Questions
What is the 35kV oil-immersed transformer used for?
It alters the voltage levels in a 35kV distribution network for the supply of the substations, industries, mining sites, and the utility systems.
What capacities are available?
It is available in 500kVA to 20,000kVA range of ratings and the secondary voltages of 0.4kV to 10kV.
What cooling method is used?
It is cooled by using ONAN method (oil natural air natural).
Do you provide test reports?
Yes, type-test and routine-test reports are provided for the project approval and certification process.
