Technical Specifications
| Parameter | Value |
|---|---|
| Model | SZ20-10000/35 |
| Product Code | 1ZX.710.9028 |
| Rated Capacity | 10000 kVA |
| Rated Frequency | 50 Hz |
| Cooling Method | ONAN (Oil Natural Air Natural) |
| Vector Group | YNd11 |
| Phases | 3-Phase |
| Service Condition | Outdoor |
| Short-Circuit Impedance | 7.67% |
| No-Load Loss | 5917 W |
| No-Load Current | 0.24% |
| Load Loss | 42860 W |
| Insulation Level | HV: LI200 / AC85 kV — LV: LI75 / AC35 kV |
| Tank Vacuum Withstand | 49 kPa |
| Insulating Oil Weight | 4545 kg |
| Active Part Weight | 10125 kg |
| Total Weight | 18730 kg |
| Standard Codes | GB1094.1, 2-2013; GB1094.3-2017; GB/T6451-2023; GB20052-2024 |
| Manufacture Date | September 2024 |
This unit is built to Grade 2 energy efficiency under GB20052-2024 as standard. Zhongxin General can also produce Grade 1 versions on request, with technical standards equal to or higher than EU Commission Regulation No. 548/2014 and Commission Regulation (EU) 2019/1783 Tier 1/2 requirements — the same efficiency benchmark we apply across our full oil-immersed transformer range. As a manufacturing factory, we also offer aluminium winding as an alternative to the standard copper configuration.
A 10000 kVA Transformer with On-Load Voltage Regulation
The SZ20-10000/35 pairs 10000 kVA capacity with a 35kV-class on-load tap changer (OLTC), giving it the “SZ” prefix on the nameplate — S for oil-immersed, Z for the tap changer. That makes it the natural upgrade path from a fixed-ratio unit such as our 8000 kVA 35kV transformer whenever a project needs to regulate secondary voltage under load rather than de-energize the unit to change taps. For projects that need still more capacity with the same OLTC principle, see our 16000 kVA OLTC transformer.
Every image on this page documents this specific SZ20-10000/35 unit through production — winding, lead processing, OLTC installation, and final dispatch — not a different capacity substituted to represent it.
Winding & Lead Wire Processing
At 10000 kVA, lead wire routing is not a mechanical afterthought — clearance to tank walls and to adjacent phases has to be verified by hand as each connection is dressed and insulated.
Once routed, leads are bound and mechanically secured so the connection geometry holds under the electromagnetic forces generated by a through-fault, protecting the winding from displacement over the transformer’s service life.
Core & Coil Assembly
The finished winding for this unit reflects the turn spacing and layer-insulation precision that ultimately shows up as the 7.67% impedance and 42860 W load-loss figures on the nameplate above.
The LV winding termination is built to match the LI75/AC35kV low-voltage insulation level specified for this unit — a higher LV insulation class than a comparable fixed-ratio transformer, reflecting the additional electrical stress introduced by the OLTC.
On-Load Tap Changer & HV/LV Lead Installation
Fitting the on-load tap changer is a multi-technician task: the OLTC has to be mechanically aligned with the winding taps and its drive shaft coupled correctly before the HV and LV leads are connected, since a misaligned OLTC is the single most common cause of in-service tap-changer faults.
Active Part Detail
Before the active part goes to drying and tanking, it is inspected as a whole — core, windings, OLTC, and lead dressing all have to sit within design tolerance, since this is the last point at which the internal assembly is visually accessible.
Completed Unit
The radiator bank on the finished unit is sized to dissipate the full no-load and load losses shown on the nameplate under natural (ONAN) cooling, without forced-air or forced-oil assistance — keeping the unit low-maintenance for outdoor, unattended substation service.
Why Zhongxin General — Our Advantages Over Other Suppliers
Real product photographs of the actual 10000 kVA unit. Every image on this page documents this specific SZ20-10000/35 transformer through production — not a different capacity or model substituted to represent it.
Complete capacity-range production tooling. Zhongxin General holds production tooling covering the full oil-immersed transformer range — 30 kVA to 100 MVA, fixed-ratio and OLTC — so this 10000 kVA unit is built with purpose-matched tooling, not adapted from a different rating.
Full in-house manufacturing cycle. Winding, lead processing, OLTC fitting, core-coil assembly, drying, oil treatment, tank fabrication and factory acceptance testing all take place at our Sichuan facility.
All energy efficiency grades available. Standard (Grade 2) and Grade 1 versions can be supplied to GB20052-2024, with Grade 1 units meeting and exceeding EU Commission Regulation No. 548/2014 and 2019/1783 requirements for international projects.
Copper and aluminium winding both available. As a manufacturing factory rather than a trading company, we can configure either winding material to match project budget and specification.
Full routine testing, every unit, test report as standard. No transformer leaves our factory without passing the complete routine test programme, documented and issued as standard order documentation.
Proven OLTC manufacturing track record. Our 8000 kVA OLTC transformer has already been exported and put into service, and our 63 MVA / 110 kV OLTC transformer case study shows our OLTC manufacturing capability at much higher capacity — giving us proven depth in tap-changer engineering well beyond this 10000 kVA rating.
Applicable Standards & Testing
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; OLTC operation check across the full tapping range; 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 GB1094 / GB/T 6451. Factory Acceptance Test (FAT) with client witness is supported.
Available Options & Configurations
- Winding material: copper (standard) or aluminium
- Energy efficiency grade: GB20052-2024 Grade 2 (standard) or Grade 1
- Frequency: 50 Hz (standard) or 60 Hz
- Vector group and LV configuration: customizable to match project requirements
- OLTC type: on-tank or in-tank, motor-driven with remote control panel
- Conservator sealing: oil-filled (standard) or nitrogen-sealed for long-distance sea freight
- Export wooden crating with full documentation package
Typical Applications
The 10000 kVA, 35kV-class OLTC oil-immersed transformer is specified for industrial substations, dedicated power-supply projects and grid-interconnection points that need to hold secondary voltage within a target band as load and upstream grid voltage vary — a requirement that a fixed-ratio unit like our 5000 kVA transformer cannot meet on its own.
Inquire About the 10000 kVA SZ20-10000/35 Transformer
Need a quotation, technical datasheet, or Factory Acceptance Test arrangement? Tell us your grid voltage, required LV output, frequency, efficiency grade, and 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, 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, including both fixed-ratio and OLTC configurations up to 120kV class — see our 6300 kVA and 8000 kVA 35kV transformer pages for adjacent capacities. Every transformer undergoes full routine testing before dispatch, with test reports issued as standard documentation.
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