Technical Specifications
| Parameter | Value |
|---|---|
| Model | SZ20-63000/110 |
| Rated Capacity | 63,000 kVA |
| Rated Voltage | 110,000 / 10,500 V |
| Rated Current | 330.7 / 3,464.1 A |
| Frequency | 50 Hz |
| Connection Symbol | YNd11 |
| Cooling Method | ONAN |
| Service Condition | Outdoor |
| Altitude | 1,500 m |
| Tank Vacuum Degree | 133 Pa |
| No-Load Current | 0.34% |
| No-Load Loss | 29.2 kW |
| Load Loss | 208.2 kW |
| Total Weight | 82,000 kg |
Insulation Levels
| Winding | Insulation Level (kV) |
|---|---|
| HV (Un/SI/LI/LIC/AC) | 126 / 395 / 480 / 530 / 200 |
| HV Neutral (Un/LI/LIC/AC) | 72.5 / 325 / 360 / 140 |
| LV (Un/LI/LIC/AC) | 12 / 75 / 85 / 35 |
Component Weights
| Component | Weight (kg) |
|---|---|
| Core & Coil Assembly | 37,630 |
| Upper Tank | 6,900 |
| Oil | 18,400 |
| Transport Weight (with oil) | 61,200 |
| Transport Weight (with nitrogen) | 48,650 |
On-Load Tap Changer — 17-Position Range
The SZ20-63000/110 uses a full 17-position on-load tap changer, giving wide voltage adjustment across the tap range without any interruption to supply:
| Position | Capacity (kVA) | Tap Voltage (V) |
|---|---|---|
| 1 (max) | 121,000 | 300.6 |
| 9a (mid) | 110,000 | 330.7 |
| 17 (min) | 99,000 | 367.4 |
This unit complies with GB20052-2024 as standard. Zhongxin General can also produce Grade 1 and other energy-efficiency-grade versions on request, with technical standards equivalent to or higher than the relevant provisions of COMMISSION REGULATION (EU) No 548/2014 and Commission Regulation (EU) 2019/1783 of 1 October 2019. As a manufacturing factory, we also offer aluminium winding as an alternative to the standard copper winding configuration.
Manufacturing Process — From Core to Commissioning
A 63,000 kVA transformer sits at a scale where every stage of production is a multi-person, precision-checked operation. The photographs below document this specific SZ20-63000/110 unit through our own production line, from bare core to final energized commissioning — not a different-capacity unit substituted to represent it.
Core Assembly
The cold-rolled grain-oriented silicon steel core is built and inspected as a standalone assembly before winding begins, confirming joint geometry and clamping alignment.
At this capacity, core stacking requires a coordinated team rather than a single operator. Joint precision and lamination alignment at this stage directly determine the 29.2 kW no-load loss figure that appears on the finished nameplate.
Winding and OLTC Installation
With the HV and LV windings fully installed on the core, the active part reaches its full insulation configuration — rated for 126/395/480/530/200 kV on the HV side.
A dedicated technician team installs the on-load tap changer onto the active part. The OLTC is what allows the SZ20-63000/110 to regulate voltage across all 17 tap positions under full load — essential for industrial and power-station applications where downtime is not an option.
Insulation Drying
Before tank assembly, the fully wound active part is loaded into vacuum drying equipment to remove residual moisture from the paper insulation. At 82 tonnes total weight, this stage requires careful handling by a coordinated technician team and is essential to achieving the rated insulation life of the unit.
Tank Fabrication and Assembly
The tank top cover is fabricated and vacuum-tested to a tolerance of 133 Pa before being fitted to the main tank body.
Primer-coated oil tank bodies are staged in the workshop ahead of assembly — each engineered to hold the 18,400 kg of insulating oil this unit requires.
A multi-technician team assembles the outer tank enclosure, fitting radiators, bushings turrets, and hardware before the completed active part is lowered in and the tank is sealed and oil-filled.
Site Installation and Commissioning
Once dispatched, the completed 63,000 kVA transformer is lifted into position on its substation foundation by crane — a scale of installation that makes clear why real project photographs matter to a buyer trying to judge what they will actually receive.
The transformer in normal, energized operation at the customer’s site — the final proof point of a real, delivered project rather than a rendering or a stock photo.
Why Zhongxin General — Our Advantages Over Other Suppliers
Real product photographs of the actual 63,000 kVA unit, start to finish. Every image on this page documents this specific SZ20-63000/110 transformer — from bare core through to energized commissioning on-site. This is fundamentally different from suppliers who substitute photographs of a different capacity, or a dry-type transformer, to represent an oil-immersed product they haven’t actually built at this scale. What you see here is what left our factory and what is now running in the field.
Complete capacity-range production tooling. Zhongxin General holds dedicated production tooling covering the full oil-immersed transformer range, from 30 kVA up to 100 MVA, including OLTC configurations at 110kV class. The 63,000 kVA unit is built with purpose-matched tooling, not adapted from a different capacity — giving consistent dimensional precision and predictable delivery timelines. Notably, we also hold complete capacity-range production molds for dry-type transformers — a manufacturing capability many suppliers in this space simply do not have — allowing us to move quickly across the full product range rather than being locked into a narrow set of standard sizes.
OLTC engineering in-house. On-load tap changer integration, motor mechanism calibration, and full-load voltage regulation testing across all 17 tap positions are performed at our own Sichuan facility, not outsourced to a third-party OLTC supplier for final assembly.
Full in-house manufacturing cycle. Core stacking, winding, insulation drying, tank fabrication, oil treatment, and factory acceptance testing all take place on one site — no outsourcing of critical steps.
All energy efficiency grades available. Standard 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.
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; induced overvoltage withstand test; separate-source AC withstand test; on-load tap changer operation test across all 17 positions.
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
- Voltage class: HV customizable to match local grid standards
- Frequency: 50 Hz (standard) or 60 Hz
- Energy efficiency grade: GB20052-2024 standard or Grade 1
- Tap changer: on-load (OLTC), 17-position, as standard on this model
- Conservator sealing: oil-filled (standard) or nitrogen-sealed for long-distance sea freight
- Export wooden crating with full documentation package
Typical Applications
The 63,000 kVA 110kV-class OLTC transformer is specified for large industrial production bases, power station step-down applications, LNG and heavy-process facilities, mining and heavy-industry supply, and any project requiring stable voltage regulation under full load at this capacity — where fixed-tap transformers cannot meet grid voltage variation requirements.
Inquire About the 63000 kVA OLTC 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 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, including OLTC configurations at 110kV class, in both GB and IEC standard configurations. Every transformer undergoes full routine testing before dispatch, with test reports issued as standard documentation.
For a documented example of this exact capacity class in the field, see our case study on the 63 MVA / 110kV OLTC transformer delivered to Ningxia’s LNG and helium project. Browse all case studies and company news to evaluate Zhongxin General as a supplier.
