China 20kV Oil Immersed Transformer Manufacturer
Subian Electric is a manufacturer of oil-immersed transformers for 20kV networks – the distribution level used across much of Europe and parts of Asia. Our 20kV oil immersed transformer range covers conventional and amorphous-core designs with 20/0.4kV ratios and ratings built to project requirements.
Produced and tested at our 50,000-square-metre factory in Xuzhou, each unit is delivered with loss data and a routine test report, supported by 350+ staff and export to more than 50 countries since 2019.
Send your rating, impedance and any network standard, and our engineers will confirm the loss figures and factory quotation.
Since 2019 · 50,000m² · 350+ Staff
Oil-Immersed Transformers We Manufacture
Conventional and amorphous-core oil-immersed transformers for 20kV networks, from distribution ratings to larger project units, with sealed or conservator tanks.
-
10kV Dry-Type Transformer-SCBH series Amorphous Alloy
-
20-35KV Dry-Type Transformer
-
20-35KV SCB Series Epoxy Resin Dry-Type Transformer
-
20KV Oil-immersed Distribution Transformer
-
35KV Oil-immersed Power Transformer
-
6-10KV Oil-Immersed Power Distribution Transformer
-
Current Transformer –10KV Indoor High Voltage
-
Current Transformer–LMZK Wound Current Transformer300/5a
-
Current Transformer–LSY-10 transformer Integrated CT
-
current transformer–LXK high voltage zero sequence
-
dry type distribution transformer-6-10 KV SCB series epoxy resin cast
-
Electrical Transformers–JDZ – 10 Power Voltage
What Is a 20kV Oil Immersed Transformer?
A 20kV oil immersed transformer is a distribution transformer whose primary is rated for a 20kV system, typically stepping down to 0.4kV for consumers or to another distribution level. Oil provides both insulation and cooling, allowing a high capacity in a compact, weatherproof tank at a lower cost than dry-type designs.
On 20kV networks these units are installed in compact substations, on plinths or on poles at smaller ratings. Because the network runs at 20kV, the transformer’s insulation level follows the 24kV equipment class, and its losses are specified against the network operator’s efficiency requirements.
- 20/0.4kV standard – for European and 20kV-network projects.
- Conventional or amorphous core – loss options to suit the network’s efficiency targets.
- Sealed & conservator tanks – both arrangements available.
- In-house production – core, winding, drying and testing on site.
- Loss data supplied – measured values in the test report.
- OEM & wholesale – private labels and volume programmes.
Core and Tank Options
Two choices shape the specification – the core material and the tank design:
Conventional silicon-steel core
the economical standard with proven loss and cost balance.
Amorphous core
a lower no-load-loss option for energy-efficiency programmes.
Sealed or conservator tank
sealed tanks are maintenance-light; conservator types allow oil expansion with a breather.
20kV Oil Immersed Transformer Technical Data
| Parameter | Specification |
|---|---|
| Rated capacity | per project (distribution range) |
| Primary voltage | 20 kV |
| Secondary voltage | 0.4 kV (400V/230V) |
| Equipment class | 24 kV maximum voltage |
| Cooling | ONAN |
| Vector group | Dyn11 / Dyn5 |
| Standard | IEC 60076 / EN 50464 |
| Testing | routine tests per unit; type tests per design |
Selecting Loss Levels for 20kV Networks
Network operators usually specify transformer losses through a loss-capitalisation formula that converts no-load and load loss into a lifetime cost. A low no-load loss matters where units run lightly for long hours; load loss matters more where they are heavily loaded.
The amorphous-core option cuts no-load loss dramatically and is increasingly specified for efficiency programmes, while conventional cores remain the economical choice for most general duty. Our quotation states both loss figures so the buyer can apply their own capitalisation.
Oil-Immersed Transformer Production and Testing
Core stacking, winding, vacuum drying, oil filling and full testing are controlled in-house, keeping the 20kV unit traceable from material to test report.
Winding & Core
Coils and cores are built for the ordered ratio, impedance and loss target.
Drying & Oil Fill
Vacuum drying protects the insulation before clean oil is introduced.
20kV Oil Immersed Transformer Price & Quotation
Request a written quotation with your rating and loss requirement. We confirm the guaranteed no-load and load-loss values, dimensions and lead time for the unit you specify.
OEM / ODM & Wholesale Supply
Distributors and network operators can take 20kV units under their own brand with standard-specific documentation.
OEM / ODM
Factory-Direct
Custom ratings, tappings and branding for 20kV markets.
Factory direct · Test docs · Export support
Wholesale Supply
Volume Pricing
Container programmes for utilities and distributors.
Factory direct · Test docs · Export support
Distributor Support
Channel Partners
Loss data and tender support for channel partners.
Factory direct · Test docs · Export support
20kV vs 10kV and 33kV Distribution
20kV carries more power per feeder than 10kV and less than 33kV, which is why it suits dense distribution areas with moderate load growth. Equipment for the three levels is otherwise similar in principle, differing in insulation, clearances and cost.
If a project operates at 20kV, the transformer must be built for the 24kV equipment class regardless of its rating. Confirm the network voltage with the operator before ordering, and choose the core and loss specification against the utility’s efficiency policy.
Choosing a 20kV Transformer Manufacturer
Check the guaranteed losses against the rating and the ecodesign or utility limit, and confirm the type-test evidence. For fleet replacements, also confirm the new unit matches the old nameplate’s vector group, impedance and tapping range.
Subian manufactures oil-immersed transformers in-house under ISO9001, ISO14001, ISO45001, CE and UL certified systems, with loss measurement in every routine test report and a 110 kV type-test report in the documentation set.
Ask how the supplier handles documentation for your network operator – consistent test formats and drawings save time at approval.
Certifications & Quality Assurance
Our oil-immersed transformer production runs under ISO9001, ISO14001 and ISO45001 systems with CE and UL certification and type-test evidence to 110 kV class.
Product Certifications
10 kV Dry-Type Transformer Certificate
35 kV Transformer CB Certificate
35 kV Transformer CE Verification
Transformer CE Certificate
Dry-Type Transformer Test Verification
ISO 14001 Environmental Management
ISO 45001 Health & Safety
ISO 9001 Quality Management
110 kV Transformer Type Test Report
UL Certificate of Compliance
20kV Oil Immersed Transformer Manufacturer FAQ
Questions about 20kV oil-immersed transformers, specifications and sourcing.
What is an oil-immersed transformer?
How much does a 20kV transformer cost?
What is the 80% rule for transformers?
Why are transformers immersed in oil?
What does 20kV mean on a transformer nameplate?
Contact Subian
Need the Right Specification?
Tell us your target market, product type, quantity and technical requirements. Our team will help you identify a suitable configuration for your project.