Technical Specifications
| Parameter | Value |
|---|---|
| Model | S11-M-400/10GY |
| Product Code | 7014B |
| Rated Capacity | 400 kVA |
| Phases | 3-Phase |
| Rated Frequency | 50 Hz |
| Vector Group | Dyn11 |
| Insulation Level | LI 75 AC 35 / LI AC 5 |
| Cooling Mode | ONAN |
| Service Conditions | Outdoor |
| Short-Circuit Impedance | 3.92% |
| Total Weight | 1153 kg |
| Ex-Factory No. | A260033 |
| Ex-Factory Date | January 2026 |
| Standard Codes | GB1094.1.2-2013 / GB/T 6451-2023 / GB 20052-2024 / GB1094.3-2017 |
Tapping Position Table:
| Tapping Position | High Voltage (V) | HV Current (A) | Low Voltage (V) | LV Current (A) |
|---|---|---|---|---|
| I | 10500 | — | — | — |
| II (Rated) | 10000 | 23.1 | 400 | 577.4 |
| III | 9500 | — | — | — |
Real Delivery Case — S11-M-400/10GY, 400 kVA
The specifications and images on this page are from actual manufactured and dispatched units — S11-M-400/10GY, produced at Zhongxin General’s Sichuan facility. Every parameter on the nameplate is verified through routine factory acceptance testing before dispatch. Every image on this page is an authentic production photograph of the 400 kVA oil-immersed transformer itself — from winding completion through core assembly, factory acceptance testing, finished product detail, and batch dispatch.
This is a meaningful distinction. Many suppliers illustrate distribution transformer pages with photographs of larger units or use stock images unrelated to the capacity being sold. What you see here is exactly what is manufactured and shipped at 400 kVA.
Manufacturing Process
Winding
The winding is the foundation of long-term transformer reliability. For the S11-M-400/10GY, the low-voltage winding is wound using high-conductivity copper foil or round wire, concentrically positioned around the silicon steel core limbs. At 400 kVA, the rated LV current reaches 577.4 A at tap position II, which demands precise conductor sizing and winding geometry to manage heat dissipation and maintain consistent impedance values. The high-voltage winding — rated at 23.1 A at 10,000 V — is wound outside the LV coil, separated by oil-impregnated insulating paper and pressboard barriers. All inter-layer insulation is pre-dried, and the complete core-and-coil assembly undergoes vacuum oil impregnation after tank enclosure.
Core Assembly
The iron core uses cold-rolled grain-oriented silicon steel, cut and stacked with a five-stage full-oblique joint configuration to minimise no-load loss and no-load current. The completed core is surface-coated with epoxy resin for corrosion protection and vibration damping before the winding coils are installed. At 400 kVA, the core cross-section is sized to keep flux density within the designed operating range across all three tap positions.
Factory Acceptance Testing
Every S11-M-400/10GY unit produced by Zhongxin General undergoes a complete routine test programme before leaving the factory. No unit is dispatched without a full test report. The test sequence covers 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; and separate-source AC withstand — all conducted to IEC 60076 and GB 1094.
Finished Product
The S11-M-400/10GY features a fully welded corrugated fin radiator tank. The corrugated steel wall serves a dual function: it provides structural rigidity equivalent to a conventional flat-plate tank with separate radiator banks, while simultaneously offering a large natural convection surface area that is sufficient for ONAN cooling at 400 kVA without any external fans, pumps, or active cooling components. The oil conservator expansion tank accommodates thermal oil volume changes and prevents moisture ingress. The fully sealed, pressure-tested design makes this unit maintenance-free throughout its service life.
Key Features
GB 20052-2024 Grade 3 energy efficiency as standard; Grade 1 available. The S11-M-400/10GY is produced to GB 20052-2024 Grade 3 as the standard configuration. Grade 1 efficiency versions are available — our Grade 1 units meet and exceed the energy efficiency requirements of EU Commission Regulation (EU) No. 548/2014 and its 2019/1783 amendment, making them directly deployable in European market projects without further modification.
Copper or aluminium winding. As a manufacturing factory, Zhongxin General produces both copper-winding and aluminium-winding versions of the S11-M-400/10GY. Aluminium-winding units offer a cost advantage while meeting the same electrical performance standards under GB and IEC. Winding material is specified at order.
Outdoor-rated, sealed corrugated tank. The tank is fully welded and pressure-tested before oil filling. ONAN cooling requires no external power, fans, or maintenance-intensive active components — the transformer operates silently and reliably throughout its design service life.
Three-position off-circuit tap changer. The standard ±2×2.5% off-circuit tap changer (positions I / II / III at 10,500 V / 10,000 V / 9,500 V) allows voltage adjustment to match local grid conditions. Adjustment is made with the transformer de-energised. On-load tap changers (OLTC) are available as a special option for applications requiring voltage regulation under load.
Full routine testing before dispatch. Every unit leaves the Sichuan factory with a complete test report — not provided on request, but issued as standard documentation with every order.
Applicable Standards & Testing
Every 400 kVA oil-immersed transformer manufactured by Zhongxin General is tested to the following 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.
Available Options & Configurations
- Winding material: copper (standard) or aluminium
- Voltage class: 6 kV, 10 kV, 11 kV, 15 kV, 22 kV, 33 kV, 35 kV; customisable to match local grid
- Low voltage: 380 V, 400 V, 415 V, 433 V, or other values
- Frequency: 50 Hz (standard) or 60 Hz
- Energy efficiency grade: GB 20052-2024 Grade 1, Grade 2, or Grade 3; EU 548/2014 Tier 1/Tier 2
- Tap changer: ±2×2.5% off-circuit (standard); OLTC available on request
- High-altitude versions for installations above 1000 m a.s.l.
- Tropical, high-humidity, and coastal salt-spray versions available
- Nitrogen-sealed tank and export wooden crating for sea freight
Dispatch & Delivery
At 400 kVA, the transformer ships fully assembled with oil filled — requiring no field assembly beyond cable termination and earthing. The total weight of 1,153 kg makes road transport straightforward with standard flatbed equipment. For international export, units are prepared with nitrogen-sealed tanks and ISPM 15-compliant wooden crating. Delivery to major Chinese ports or direct to project sites across China is available. Zhongxin General has supplied transformers to projects in Europe, Central Asia, South Asia, and Africa — export documentation, CE Declaration of Conformity, and third-party inspection arrangements are handled in-house.
Why Zhongxin General — Manufacturer Advantages
Authentic production photographs at the actual capacity. Every image on this page is a genuine production photo of a 400 kVA unit — from winding through to dispatch. Many suppliers illustrate pages for this capacity with images of larger-capacity units or with manufacturer stock photographs that bear no relation to what is actually built. Our production-line photographs give you verifiable evidence of our 400 kVA manufacturing capability.
Complete capacity-range production tooling. Zhongxin General holds production tooling and dies covering the complete range from 30 kVA to 100 MVA for oil-immersed transformers. The 400 kVA S11-M has its own dedicated core, winding, and tank tooling — consistent dimensional precision and reliable impedance values, even for smaller-capacity orders.
Both winding materials in-house. Copper-winding and aluminium-winding versions are manufactured at the same Sichuan facility under the same quality system — factory-direct pricing on both options without a sub-supplier in the chain.
Grade 1 efficiency available. Our Grade 1 efficiency versions (GB 20052-2024) exceed the energy efficiency requirements of EU Commission Regulation (EU) No. 548/2014 and 2019/1783 — supporting international buyers who need EU-compliant supply from a Chinese factory.
Verified delivery track record. Our project case studies and company news document real deliveries — from small distribution transformers to 63 MVA / 110 kV units — with authentic factory and site photographs on every project.
National “Little Giant” Enterprise status. Zhongxin General holds China’s National “Little Giant” Enterprise designation and National High-Tech Enterprise certification — the highest innovation recognition for SME manufacturers in China.
Typical Applications
The 400 kVA oil-immersed distribution transformer is widely used in rural distribution networks, commercial and light industrial facilities, agricultural power supply, prefabricated box-type substations, township distribution networks, and medium-scale manufacturing sites. Its outdoor-rated corrugated tank, maintenance-free ONAN cooling, and 30+ year design service life make it one of the most cost-effective power distribution solutions at this capacity. The Dyn11 vector group provides a neutral on the low-voltage side and effectively suppresses third-harmonic voltages — a standard requirement for four-wire distribution systems supplying mixed single-phase and three-phase loads.
For smaller capacity requirements, see our 200 kVA oil-immersed transformer and 315 kVA oil-immersed transformer. For the complete range, visit our oil-immersed transformer product page.
Inquire About 400 kVA Oil-Immersed Transformer
Need a quotation, technical datasheet, or delivery schedule? Tell us your grid voltage, required LV output, frequency, efficiency grade, winding material, and installation conditions — and we will configure the right unit and provide pricing and lead time.
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 at No. 998 Xinghua 5 Road, Xinjin District, Chengdu, Sichuan Province, the company holds National “Little Giant” Enterprise status and National High-Tech Enterprise certification. Our oil-immersed transformer portfolio covers 30 kVA to 100 MVA, configurable to 6 kV, 10 kV, 11 kV, 22 kV, 33 kV, 35 kV, 66 kV, 110 kV, and 132 kV voltage classes in copper or aluminium winding, to GB and IEC standards.
Every transformer undergoes full routine testing before dispatch. Test reports are issued as standard documentation with every order.
