Technical Specifications
| Parameter | Value |
| Product Type | Power Transformer |
| Model | S13-M-315/10 |
| Phases | 3-Phase |
| Rated Capacity | 315 kVA |
| Rated Frequency | 50 Hz |
| High Voltage | 10 kV (±2×2.5% tap) |
| Low Voltage | 400 V |
| Rated HV Current (Tap II) | 18.19 A |
| Rated LV Current (Tap II) | 454.7 A |
| Vector Group | Dyn11 |
| Insulation Level | LI 75 AC 35 / LI AC 5 |
| Cooling Method | ONAN |
| Service Condition | Outdoor |
| No-Load Loss (P₀) | 400 W (Grade 2, Dyn11) |
| Load Loss (Pk, 75°C) | 3,250 W |
| Short-Circuit Impedance (Uk) | 4% |
| No-Load Current (I₀) | ≤1.1% |
| Applicable Standards | GB1094.1.2-2013, GB1094.3-2017, GB/T6451-2015, GB 20052-2020 |
| Energy Efficiency | GB 20052-2020 Grade 1 / Grade 2 / Grade 3 |
The parameters above conform to GB/T 6451-2015 and GB 20052-2020 requirements for the S13-M series at 315 kVA / 10 kV. Every unit is verified through routine factory acceptance testing before dispatch. Grade 1 energy efficiency versions meeting EU Commission Regulation No. 548/2014 Tier 1 and Tier 2 are available on request.
Manufacturing Process — From Core to Dispatch
Every image on this page documents the actual 315 kVA production process at our Sichuan factory — not stock photographs of a different capacity. What you see is what is manufactured.
Iron Core — Foundation of Low-Loss Performance
The iron core of the S13-M-315/10 is fabricated from high-grade cold-rolled grain-oriented silicon steel sheets, cut and laminated with precision 45° mitre joints. The stepped-lap lamination technique minimises joint air gaps, which is the primary driver of the no-load loss and no-load current reduction compared to older S11 designs. Core quality cannot be recovered at a later production stage — it is the foundation on which every other performance parameter rests.
The batch production line shown above reflects our standard output cadence for the 315 kVA capacity. Purpose-built tooling matched to this specific capacity ensures consistent dimensional precision across every unit in a batch — a practical advantage for buyers procuring multiple units for a single project or for repeat orders.
Winding — Precision Determines Electrical Performance
The high-voltage winding uses oxygen-free enamelled copper wire wound to precise turn counts, with oil-impregnated insulating paper between layers. The low-voltage winding adopts a cylindrical or foil structure matched to the rated LV current of 454.7 A at tap position II. Both HV and LV coils are wound to tolerances that directly determine the no-load loss, load loss, and short-circuit impedance shown in the table above.
The HV and LV end close-ups document the coil geometry, terminal connections, and inter-winding clearances from both sides of the assembled active part. These are not representative photographs — they are from this production run.
Lead Wire Processing
Following winding, the active part moves to lead wire arrangement and connection preparation. Insulation clearances between HV and LV leads are verified against design drawings before the assembly progresses. Correct lead wire routing and secure terminations at this stage are what determine the unit’s long-term reliability in the field — faults in this area account for a disproportionate share of distribution transformer failures in service.
Corrugated Fin Radiator Tank
The completed active part is enclosed in a corrugated fin radiator tank, which provides ONAN natural oil and air cooling without the need for external radiator panels or forced cooling equipment. The corrugated fin design increases effective cooling surface area while keeping the overall footprint compact — a well-established configuration for distribution transformer capacities up to 500 kVA that is straightforward to maintain in the field. Every tank is pressure-tested and inspected for weld quality before the active part is lowered in.
Applicable Standards & Testing
Every 315 kVA oil-immersed transformer manufactured by Zhongxin General undergoes a full routine test programme before leaving the factory. No unit is dispatched without a complete test report.
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 and ITP documentation are provided as standard with every order.
Available Options & Configurations
- Winding material: copper (standard) or aluminium
- Voltage class: 6 kV, 10 kV, or 35 kV; HV customisable to match local grid standards
- Low voltage: 380 V, 400 V, 415 V, 433 V, or other values to match local grid
- Frequency: 50 Hz (standard) or 60 Hz
- Energy efficiency grade: GB 20052-2020 Grade 1, Grade 2, or Grade 3
- Tap changer: ±2×2.5% off-circuit (standard); on-load tap changer (OLTC) available on request
- Service conditions: outdoor (standard); indoor version available
- Oil type: mineral oil (standard); silicone oil for high-fire-safety environments on request
- Nitrogen-sealed tank for long-distance sea freight
- Export wooden crating with full documentation package
Typical Applications
The 315 kVA oil-immersed distribution transformer occupies a practical mid-range in the distribution capacity bracket — larger than the small rural units used for single-feeder agricultural supply, and smaller than the 500 kVA and above units required for medium industrial loads. At 10 kV / 400 V with Dyn11 vector group and ONAN cooling, it is a standard specification for light-to-medium industrial facilities, commercial buildings, township distribution networks, and grid-connected renewable energy projects where the generation point and the local load require a dedicated step-down unit. The Dyn11 vector group provides a neutral on the low-voltage side, enabling both three-phase and single-phase distribution from the same secondary winding — a practical requirement in most end-use distribution applications.
Our export experience with this capacity range spans Europe, Central Asia, South Asia, and Africa. The same logistics, documentation, and Factory Acceptance Test processes that supported our 1250 kVA dry-type transformer export to Europe, our 5000 kVA step-up transformer for the Nepal Chino Hydropower Station, and our prefabricated substation for Aktau Port, Kazakhstan apply equally to 315 kVA distribution transformer orders.
Why Zhongxin General — Key Advantages
Real production photographs at the actual capacity. Every image on this page shows the 315 kVA unit itself — from core lamination through to the finished corrugated fin tank. Many suppliers illustrate distribution transformer pages with photographs of unrelated capacities or manufacturer stock images. Our production photographs give you verifiable evidence of what we manufacture at 315 kVA.
Complete capacity-range production tooling. Zhongxin General holds production tooling across the full oil-immersed transformer capacity range from 30 kVA to 100 MVA. The 315 kVA unit is manufactured with purpose-built tooling — not adapted from a different capacity — which delivers consistent impedance values, reliable dimensional precision, and predictable delivery timelines.
Full in-house production cycle. Core lamination, winding, active part assembly, insulation drying, oil treatment, tank assembly, and factory acceptance testing are all performed at our Sichuan facility. No outsourcing of critical manufacturing steps.
All energy efficiency grades available. We produce Grade 1, Grade 2, and Grade 3 versions to GB 20052-2020. Our Grade 1 units meet and exceed EU Commission Regulation No. 548/2014 and 2019/1783 Tier 1 and Tier 2 requirements.
Copper and aluminium winding both available. As a manufacturing factory, we offer both configurations — something trading companies and agents cannot offer without factory involvement.
Full routine testing, every unit, test report as standard. No transformer leaves our factory without passing the complete routine test programme. Test reports are issued as standard documentation with every order, not provided only on request. Browse our case studies for documented delivery evidence.
Inquire About 315 kVA Oil-Immersed Transformer
Need a quotation, technical datasheet, or Factory Acceptance Test arrangement for the 315 kVA oil-immersed distribution transformer? Tell us your grid voltage, required LV output, frequency, efficiency grade, and any special environmental or installation conditions — and we will configure the right unit for your project.
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 — China’s highest SME innovation designation — 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 for domestic and international projects.
Every transformer we manufacture undergoes full routine testing to IEC 60076 or GB 1094 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.
