Technical Specifications
| Parameter | Value |
|---|---|
| Manufacturer | Sichuan Zhongxin General Electric Energy Co., Ltd. |
| Product Type | S11-2500/10GY |
| Product Code | 1ZX.710.7122A |
| Rated Capacity | 2500 kVA |
| Vector Group | Dyn11 |
| Number of Phases | 3 (Three-phase) |
| Rated Frequency | 50 Hz |
| Cooling Mode | ONAN |
| Service Conditions | Outdoor |
| Insulation Level | LI 75 AC 35 / LI AC 5 |
| Short-Circuit Impedance | 5.00% |
| Total Weight | 5,640 kg |
| Ex-factory No. | A240529 |
| Ex-factory Date | November 2024 |
| Standard Codes | GB1094.1.2-2013 / GB1094.3-2017 / GB/T6451-2015 / GB20052-2020 |
Tapping Position Table
| Tap Position | HV Voltage (V) | HV Current (A) | LV Voltage (V) | LV Current (A) |
|---|---|---|---|---|
| I | 10500 | — | — | — |
| II | 10250 | — | — | — |
| III (Rated) | 10000 | 144.3 | 400 | 3608.4 |
| IV | 9750 | — | — | — |
| V | 9500 | — | — | — |
This unit complies with China GB 20052-2020 at the Grade 3 energy efficiency level as standard. Zhongxin General can also produce Grade 1 and Grade 2 versions on request — Grade 1 products meet and exceed the requirements of EU Commission Regulation No. 548/2014 and Commission Regulation (EU) 2019/1783, making them directly deployable for European and EU-aligned market projects.
2500 kVA — Engineering Considerations at This Capacity
At 2500 kVA, the rated low-voltage current reaches 3,608.4 A — a figure that places significant demands on every stage of the installation. Busbar cross-section, contact resistance at bolted joints, cable lug sizing and protective relay settings all need to be engineered to this current level rather than scaled from a smaller unit. The S11-2500/10GY sits at a capacity point where a single transformer can serve an entire mid-size industrial facility or a substantial commercial complex, and where the consequences of an undersized or improperly installed unit are immediately felt in voltage drop and thermal performance.
The five-tap off-circuit tap changer spanning 9,500 V to 10,500 V (±2×2.5%) reflects the reality of 10 kV distribution grids in China and internationally: grid voltage at the delivery point is rarely exactly nominal, and the tap range gives the site engineer the flexibility to set the LV output at the correct level for the load without disrupting supply.
Every image on this page documents this specific unit. It is common practice among suppliers to illustrate a given capacity’s product page with photographs from a different, often larger unit because they lack in-house tooling at the listed capacity. Zhongxin General holds dedicated production tooling across the full distribution transformer range, and the unit shown here is the 2500 kVA unit itself — photographed during finishing, accessory fitting and pre-dispatch stages at our Xinjin District, Chengdu factory.
Cooling System — ONAN at 2500 kVA
At 2500 kVA, the ONAN cooling mode remains effective when the corrugated fin radiator is sized correctly for the load loss and ambient temperature design point. The fin panels on this unit provide the surface area required to dissipate full-load heat through natural oil convection inside the tank and natural air convection across the external fin surfaces — no fans, no pumps, no active cooling components. This translates directly into maintenance simplicity: there are no motors to fail, no bearings to replace, and no auxiliary power consumption associated with the cooling system for the life of the unit.
The corrugated fin geometry also gives the tank wall structural rigidity while allowing the oil volume to expand and contract with temperature cycling through elastic deformation of the fins — eliminating the need for a separate expansion vessel at this capacity in a hermetically sealed design.
HV and LV Terminals
The HV side presents five tap positions accessible via the off-circuit tap changer, covering 9,500 V to 10,500 V. Adjustment is made with the transformer de-energised. The LV side is configured for 400 V output at the rated (III) tap, with a Dyn11 vector group that places the LV winding 30° behind the HV winding — the standard configuration for distribution networks where the neutral is required on the secondary side and where harmonic management through phase displacement is beneficial in multi-transformer installations.
The LI 75 AC 35 insulation level on the HV side means this transformer is rated to withstand a 75 kV lightning impulse and a 35 kV power-frequency withstand test — standard for 10 kV class outdoor distribution transformers, verified by type test and confirmed by the insulation withstand tests in the routine test programme conducted before dispatch.
Application: Integrated into Prefabricated Substations
One of the most common deployment configurations for the 2500 kVA oil-immersed transformer is integration into a prefabricated (box-type) substation. As the photograph above shows, the S11-2500/10GY is dimensioned to fit within Zhongxin General’s own prefabricated substation enclosures, allowing the complete HV/transformer/LV package to be factory-assembled, tested as a system, and delivered to site as a single unit requiring only civil foundation work and external cable connections.
This integration is particularly relevant for projects where site construction time is constrained — industrial parks, data centre campuses, port facilities, and infrastructure projects where the power supply must be ready before other construction phases can proceed. For export projects, the prefabricated substation format also simplifies customs and logistics, as the transformer arrives pre-integrated rather than requiring assembly by local personnel. See the Aktau Port Kazakhstan prefabricated substation case study for a documented example at a similar capacity level.
Dispatch
At a total weight of 5,640 kg, the 2500 kVA unit requires a heavy-duty flatbed for road transport. Once routine testing is complete, the unit is crane-loaded, blocked and secured according to our standard transport procedures. For domestic projects, the transformer is shipped oil-filled and ready for installation. For international export, units can be prepared with nitrogen sealing of the tank and ISPM 15-compliant wooden crating — the same logistics process documented in our international project deliveries to Central Asia, South Asia, Africa and Europe. See company news for recent dispatch records.
Key Features — 2500 kVA Oil-Immersed Transformer
Five-position off-circuit tap changer. HV taps at 10500 / 10250 / 10000 / 9750 / 9500 V (±2×2.5%) allow output voltage adjustment to match local 10 kV grid conditions without interrupting supply on adjacent feeders — adjustment is made de-energised.
ONAN cooling, no auxiliary systems. Natural oil and air cooling with corrugated fin radiator panels. No fans, pumps or auxiliary power draw. Maintenance requirements are limited to periodic oil quality checks and visual inspection of bushings and fittings.
5.00% short-circuit impedance. Verified by routine test on every unit. The 5% value gives system designers a confirmed fault-current and voltage-drop input rather than a nominal estimate, and is typical for distribution transformers at this capacity in the 10 kV class.
3,608.4 A rated LV current. At this current level, the LV termination engineering — busbar sizing, lug selection and torque requirements — must be specified to the confirmed value. Zhongxin General can provide connection engineering guidance as part of the project documentation package.
GB 20052-2020 Grade 3 standard; Grade 1 available. The standard unit ships at Grade 3 efficiency. Grade 1 efficiency versions are available and meet and exceed EU Commission Regulation No. 548/2014 and 2019/1783 energy efficiency requirements, making them directly usable for European and EU-aligned market projects without additional compliance engineering.
Copper winding standard; aluminium available. Both winding options are manufactured in-house. Copper offers lower losses over the transformer’s life; aluminium offers a lower initial cost. The choice can be specified at order and does not affect delivery lead time.
Applicable Standards & Testing
Every 2500 kVA oil-immersed transformer manufactured by Zhongxin General undergoes a complete routine test programme before dispatch.
Routine tests (every unit): winding resistance measurement; voltage ratio and vector group verification; no-load loss and no-load current; load loss and short-circuit impedance; induced overvoltage withstand test; separate-source AC withstand test.
Type tests (reports available on request): temperature rise test; lightning impulse test.
Special tests (available on request): partial discharge measurement; sound level (noise) measurement; short-circuit withstand test.
All tests are conducted to IEC 60076 and GB 1094 / GB/T 6451. Factory Acceptance Test (FAT) with client witness is supported. Test reports are provided as standard documentation with every order.
Available Options & Configurations
Winding material: copper (standard) or aluminium. Voltage class: 6 kV, 10 kV, or 35 kV; HV customizable to match local grid standards including 11 kV, 22 kV, 33 kV. Low voltage: 380 V, 400 V, 415 V, 433 V, or other values. Frequency: 50 Hz (standard) or 60 Hz. Energy efficiency grade: GB 20052-2020 / GB 20052-2024 Grade 1, Grade 2, or Grade 3. Tap changer: ±2×2.5% off-circuit (standard); on-load tap changer (OLTC) available on request. Oil type: mineral oil (standard); alternative dielectric fluids available for special environments. Nitrogen-sealed tank for long-distance sea freight. Export wooden crating with full documentation package.
For our complete oil-immersed transformer range from 30 kVA to 100 MVA, or to compare with our dry-type transformer range, see the respective product category pages.
Typical Applications
The 2500 kVA oil-immersed transformer is typically specified for large industrial workshops and heavy manufacturing facilities, commercial complexes and logistics hubs, dedicated substations for single large consumers, data centre power distribution at medium capacity, integrated prefabricated substations for infrastructure projects, and as a step-down main transformer in multi-transformer substation configurations. At 10 kV / 400 V with Dyn11 vector group and ONAN cooling, it is the standard configuration for medium-scale grid connection across China and in international markets following IEC or GB standards.
Why Zhongxin General — Manufacturer Advantages
Authentic production photographs of the actual 2500 kVA unit. Every photograph on this page — nameplate, complete unit, cooling fins, HV side, LV side, prefabricated substation integration, and truck dispatch — documents this specific capacity, produced at our Sichuan facility. Substituting photographs from other capacities or product lines is standard practice among trading companies and suppliers without in-house tooling at the listed capacity.
Dedicated capacity-range tooling. Zhongxin General holds dedicated winding fixtures, core lamination tooling and tank fabrication tooling spanning the full oil-immersed range. The 2500 kVA unit uses its own purpose-built production fixtures, ensuring dimensional consistency from unit to unit and predictable lead times.
Factory, not trading company. Sichuan Zhongxin General Electric Energy Co., Ltd. is a National “Little Giant” Enterprise and National High-Tech Enterprise manufacturing at our own facility in Xinjin District, Chengdu. Core lamination, winding, tank fabrication, oil processing and routine testing all happen on one site.
Both copper and aluminium winding options. Manufactured in-house on separate production lines, not sourced from sub-suppliers.
EU-compliant efficiency grades. Grade 1 efficiency products exceed EU Commission Regulation No. 548/2014 and 2019/1783 requirements. See the 1250 kVA dry-type transformer European export case study for how we handle EU compliance documentation in practice.
Documented international project track record. Browse all case studies for verified delivery examples across China, Central Asia, South Asia, Africa and Europe — with factory and site photographs on every project.
Inquire About 2500 kVA Oil-Immersed Transformer
Need a quotation, technical datasheet, or Factory Acceptance Test arrangement for the 2500 kVA oil-immersed transformer? Provide your grid voltage, required LV output, frequency, efficiency grade, winding material preference, and any special installation or environmental conditions — and we will configure the correct unit for your project and provide pricing and timeline.
Contact Us for Price & Datasheet
About Zhongxin General — Oil-Immersed Transformer Manufacturer & Factory
Zhongxin General (Sichuan Zhongxin General Electric Energy Co., Ltd.) is a China-based manufacturer and factory specialising in oil-immersed power transformers and dry-type power transformers, HV/MV/LV switchgear, prefabricated substations, and energy storage systems. Headquartered in Xinjin District, Chengdu, Sichuan Province, the company holds National “Little Giant” Enterprise status alongside National High-Tech Enterprise certification.
Our oil-immersed transformer portfolio covers 30 kVA to 100 MVA, configurable to 6 kV, 10 kV, 35 kV, 66 kV, 110 kV and higher voltage classes, in both GB and IEC standard configurations. Every unit undergoes full routine testing before dispatch; test reports are issued as standard documentation with every order.
Browse all case studies → and company news → to evaluate Zhongxin General as a supplier.
