20-35kV SCB Series Epoxy Dry-Type Transformer
The 20-35kV SCB series epoxy resin dry-type transformer delivers reliable power for critical infrastructure such as urban grids, commercial centers, and hospitals. Designed for safety and low maintenance, it features flame-retardant construction, smart temperature control, and efficient cooling.
A Brief Introduction to the 20-35kV SCB Epoxy Dry-Type Transformer
The 20-35kV SCB series dry-type transformer provides high-voltage distribution applications with oil-free, flame-resistant technology. Available in SCB10, SCB11, and SCB12 efficiency levels, this high-voltage dry-type transformer utilizes vacuum-impregnated resin insulation for the primary windings and foil-type low-voltage windings. This design—combined with axial cooling ducts—allows compact construction while meeting GB/T and IEC 60076 standards. These transformers support 50Hz or 60Hz electrical networks at capacities ranging from 50kVA to 2500kVA.
The SCB series optimizes cooling through cross-flow top-blown fans and includes intelligent temperature controls. An RS485 interface provides centralized monitoring and fault alerts. The transformer’s resin-coated core offers moisture, corrosion, and rust resistance, ensuring reliable operation in coastal, tropical, and heavily polluted environments. Available with IP20 (indoor) or IP23 (outdoor) enclosures in cold-rolled or stainless steel, this transformer adapts for use in indoor substations, kiosks, or underground power stations. Key specifications include a primary voltage range of 20kV to 24kV, ±2×2.5% or ±5% tapping options, and dual-voltage interchange between 20kV and 10kV. Insulation is rated class F or H with load losses reference temperatures of 120°C or 145°C.
Optional configurations include stainless steel enclosures and custom busbars.
Benefits and Key Advantages of 20-35kV SCB Dry-Type Transformers
Improved Safety
Flame-retardant, fireproof, and explosion-proof — no hazardous oil, making them suitable for densely populated and underground sites.
Minimal Maintenance
Resin-sealed windings and rust-resistant cores require only visual inspections; no risk of oil leaks or the need for dielectric testing.
Energy Efficient
SCB12 reduces no-load losses by up to 20% compared to SCB10, significantly lowering lifecycle energy costs.
Quiet Operation
Low-noise cross-flow fans and solid resin encapsulation keep sound levels below 65dB, ideal for hospitals and schools.
Smart Monitoring
Integrated temperature sensors with RS485 links to SCADA or BMS provide real-time alerts and automated fan controls.
Durable Construction
Epoxy resin insulation resists moisture, salt, and industrial contaminants, ensuring long-term reliable operation.
Uses and Industries
Urban Power Grids
High-density load centers and kiosk substations in urban areas benefit from compact and fire-safe transformer designs.
Commercial and Institutional
Hospitals, universities, airports, and shopping centers appreciate quiet, oil-free operation and smart monitoring features.
Public Transportation
Railway stations, subways, tunnels, and ports require vibration-resistant, low-maintenance dry-type designs.
Industrial and Offshore
Ships, offshore platforms, and underground power stations utilize moisture-resistant epoxy-insulated transformers.
Technical Data & Specifications
20-35kV SCB series epoxy dry-type transformer parameters. SCB10, SCB11, and SCB12 models available. Load loss values correspond to reference temperatures per GB/T 1094.1: B (100°C), F (120°C), H (145°C). Tables also applicable to 20/10kV dual-voltage interchange transformers.
SC(B)10 Series
| Rated Capacity (kVA) | High Voltage (kV) | Tap Range | Low Voltage (kV) | Connection | No-load Loss (kW) | Load Loss (kW) by Insulation Class | No-load Current (%) | Impedance (%) | ||
|---|---|---|---|---|---|---|---|---|---|---|
| B(100℃) | F(120℃) | H(145℃) | ||||||||
| 50 | 20; 22; 24 | ±2×2.5% ±5% | 0.4 | Dyn11 Yyn0 | 0.34 | 1.16 | 1.23 | 1.31 | 2.0 | 6.0 |
| 100 | Dyn11 Yyn0 | 0.54 | 1.87 | 1.99 | 2.13 | 1.8 | 6.0 | |||
| 160 | Dyn11 Yyn0 | 0.67 | 2.33 | 2.47 | 2.64 | 1.5 | 6.0 | |||
| 200 | Dyn11 Yyn0 | 0.73 | 2.77 | 2.94 | 3.14 | 1.5 | 6.0 | |||
| 250 | Dyn11 Yyn0 | 0.84 | 3.22 | 3.42 | 3.66 | 1.3 | 6.0 | |||
| 315 | Dyn11 Yyn0 | 0.97 | 3.85 | 4.08 | 4.36 | 1.3 | 6.0 | |||
| 400 | Dyn11 Yyn0 | 1.15 | 4.65 | 4.84 | 5.18 | 1.1 | 6.0 | |||
| 500 | Dyn11 Yyn0 | 1.35 | 5.46 | 5.79 | 6.19 | 1.1 | 6.0 | |||
| 630 | Dyn11 Yyn0 | 1.53 | 6.45 | 6.84 | 7.32 | 1.0 | 6.0 | |||
| 800 | Dyn11 Yyn0 | 1.75 | 7.79 | 8.26 | 8.84 | 1.0 | 6.0 | |||
| 1000 | Dyn11 Yyn0 | 2.07 | 9.22 | 9.78 | 10.4 | 0.85 | 6.0 | |||
| 1250 | Dyn11 Yyn0 | 2.38 | 10.8 | 11.5 | 12.3 | 0.85 | 6.0 | |||
| 1600 | Dyn11 Yyn0 | 2.79 | 13.0 | 13.8 | 14.8 | 0.85 | 6.0 | |||
| 2000 | Dyn11 Yyn0 | 3.24 | 15.4 | 16.3 | 17.5 | 0.7 | 6.0 | |||
| 2500 | Dyn11 Yyn0 | 3.87 | 18.2 | 19.3 | 20.7 | 0.7 | 6.0 | |||
| 2000 | Dyn11 Yyn0 | 3.24 | 16.8 | 17.8 | 19.1 | 0.7 | 8.0 | |||
| 2500 | Dyn11 Yyn0 | 3.87 | 20.0 | 21.2 | 22.7 | 0.7 | 8.0 | |||
SC(B)11 Series
| Rated Capacity (kVA) | High Voltage (kV) | Tap Range | Low Voltage (kV) | Connection | No-load Loss (kW) | Load Loss (kW) by Insulation Class | No-load Current (%) | Impedance (%) | ||
|---|---|---|---|---|---|---|---|---|---|---|
| B(100℃) | F(120℃) | H(145℃) | ||||||||
| 50 | 20; 22; 24 | ±2×2.5% ±5% | 0.4 | Dyn11 Yyn0 | 0.31 | 1.16 | 1.23 | 1.31 | 2.0 | 6.0 |
| 100 | Dyn11 Yyn0 | 0.48 | 1.87 | 1.99 | 2.13 | 1.8 | 6.0 | |||
| 160 | Dyn11 Yyn0 | 0.60 | 2.33 | 2.47 | 2.64 | 1.5 | 6.0 | |||
| 200 | Dyn11 Yyn0 | 0.65 | 2.77 | 2.94 | 3.14 | 1.5 | 6.0 | |||
| 250 | Dyn11 Yyn0 | 0.75 | 3.22 | 3.42 | 3.66 | 1.3 | 6.0 | |||
| 315 | Dyn11 Yyn0 | 0.87 | 3.85 | 4.08 | 4.36 | 1.3 | 6.0 | |||
| 400 | Dyn11 Yyn0 | 1.03 | 4.65 | 4.84 | 5.18 | 1.1 | 6.0 | |||
| 500 | Dyn11 Yyn0 | 1.21 | 5.46 | 5.79 | 6.19 | 1.1 | 6.0 | |||
| 630 | Dyn11 Yyn0 | 1.38 | 6.45 | 6.84 | 7.32 | 1.0 | 6.0 | |||
| 800 | Dyn11 Yyn0 | 1.57 | 7.79 | 8.26 | 8.84 | 1.0 | 6.0 | |||
| 1000 | Dyn11 Yyn0 | 1.86 | 9.22 | 9.78 | 10.4 | 0.85 | 6.0 | |||
| 1250 | Dyn11 Yyn0 | 2.14 | 10.8 | 11.5 | 12.3 | 0.85 | 6.0 | |||
| 1600 | Dyn11 Yyn0 | 2.51 | 13.0 | 13.8 | 14.8 | 0.85 | 6.0 | |||
| 2000 | Dyn11 Yyn0 | 2.92 | 15.4 | 16.3 | 17.5 | 0.7 | 6.0 | |||
| 2500 | Dyn11 Yyn0 | 3.48 | 18.2 | 19.3 | 20.7 | 0.7 | 6.0 | |||
| 2000 | Dyn11 Yyn0 | 2.92 | 16.8 | 17.8 | 19.1 | 0.7 | 8.0 | |||
| 2500 | Dyn11 Yyn0 | 3.48 | 20.0 | 21.2 | 22.7 | 0.7 | 8.0 | |||
SC(B)12 Series
| Rated Capacity (kVA) | High Voltage (kV) | Tap Range | Low Voltage (kV) | Connection | No-load Loss (kW) | Load Loss (kW) by Insulation Class | No-load Current (%) | Impedance (%) | ||
|---|---|---|---|---|---|---|---|---|---|---|
| B(100℃) | F(120℃) | H(145℃) | ||||||||
| 50 | 20; 22; 24 | ±2×2.5% ±5% | 0.4 | Dyn11 Yyn0 | 0.27 | 1.16 | 1.23 | 1.31 | 2.0 | 6.0 |
| 100 | Dyn11 Yyn0 | 0.43 | 1.87 | 1.99 | 2.13 | 1.8 | 6.0 | |||
| 160 | Dyn11 Yyn0 | 0.53 | 2.33 | 2.47 | 2.64 | 1.5 | 6.0 | |||
| 200 | Dyn11 Yyn0 | 0.58 | 2.77 | 2.94 | 3.14 | 1.5 | 6.0 | |||
| 250 | Dyn11 Yyn0 | 0.67 | 3.22 | 3.42 | 3.66 | 1.3 | 6.0 | |||
| 315 | Dyn11 Yyn0 | 0.77 | 3.85 | 4.08 | 4.36 | 1.3 | 6.0 | |||
| 400 | Dyn11 Yyn0 | 0.92 | 4.65 | 4.84 | 5.18 | 1.1 | 6.0 | |||
| 500 | Dyn11 Yyn0 | 1.08 | 5.46 | 5.79 | 6.19 | 1.1 | 6.0 | |||
| 630 | Dyn11 Yyn0 | 1.22 | 6.45 | 6.84 | 7.32 | 1.0 | 6.0 | |||
| 800 | Dyn11 Yyn0 | 1.40 | 7.79 | 8.26 | 8.84 | 1.0 | 6.0 | |||
| 1000 | Dyn11 Yyn0 | 1.65 | 9.22 | 9.78 | 10.4 | 0.85 | 6.0 | |||
| 1250 | Dyn11 Yyn0 | 1.90 | 10.8 | 11.5 | 12.3 | 0.85 | 6.0 | |||
| 1600 | Dyn11 Yyn0 | 2.23 | 13.0 | 13.8 | 14.8 | 0.85 | 6.0 | |||
| 2000 | Dyn11 Yyn0 | 2.59 | 15.4 | 16.3 | 17.5 | 0.7 | 6.0 | |||
| 2500 | Dyn11 Yyn0 | 3.10 | 18.2 | 19.3 | 20.7 | 0.7 | 6.0 | |||
| 2000 | Dyn11 Yyn0 | 2.59 | 16.8 | 17.8 | 19.1 | 0.7 | 8.0 | |||
| 2500 | Dyn11 Yyn0 | 3.10 | 20.0 | 21.2 | 22.7 | 0.7 | 8.0 | |||
Contact us for detailed SCB dry type transformer specifications, dimension drawings, and enclosure configuration options.
What To Expect When Purchasing 20-35kv SCB Dry-type Transformer
Factory Direct Manufacturer
As an experienced dry transformer manufacturer, we manufacture 20-35kV SCB series units with complete in-house resin casting and testing.
Testing Accredited By Regulatory Bodies
All units are tested according to IEC 60076-11: winding resistance, dielectric strength, partial discharge and temperature rise verification.
Cost Competitive
We have an extensive inventory of SCB dry-type transformers and are supplying utility companies and EPC contractors around the world directly from our factory at /competitive prices/.
Dependable Shipping Times
Standard SCB models ship within 6-8 weeks; customized enclosure materials, busbar layouts, and monitoring packages are available.
Standard Certifications
IEC 60076-11 GB/T 1094 ISO 9001 CE RoHS
Buyer’s Guide
How 20-35kv SCB Dry Type Transformer Fits High Voltage Project
Assistance for electrical contractors and facility managers who need to choose a dry-type transformer for use in 20-35kV networks.
Project Use
SCB transformers are suitable for urban substations because of their fire-safe and compact design allowing them to be installed in switchgear integrated with buildings without an oil containment solution 20-35kV transformer for hospitals and airports where noise and smart monitoring assure that there will never be an interruption to electrical service. SCB Dry Type Transformers can be used for industrial marine and ship operations due to the moisture-resistant resin insulation and corrosion-free stainless steel enclosure.
SCB10 vs SCB11 vs SCB12 – Efficiency Comparison
SCB10 has been engineered to perform economically on a cost basis (cost / benefit) for non-specialty projects. SCB11 reduces no-load loss by ~10% over SCB10 and SCB12 offers the lowest losses of approximately 20%, compared to SCB10 and is more economical for ongoing-duty installations. SCB10, SCB11 and SCB12 will have identical footprints and installation requirements.
Installation, Protection & Monitoring
The IP20 rating is intended for indoors in ‘clean’ environments and the IP23 rating is intended for outdoors, in dusty and/or humid conditions. RS485 is available on the SCB dry-type transformer and is compatible with existing BMS or SCADA systems. Custom copper busbar outlets to side, top and/or closed bus are available for direct compatibility to existing switching gear. The only regular maintenance required is cleaning fan filters and visual inspection.
Frequently Asked Questions
What is a dry type transformer?
A dry type transformer uses solid insulation — such as epoxy resin — and air for cooling instead of flammable liquids. It is the preferred choice for indoor, fire-sensitive, and high-voltage applications where safety and low maintenance are priorities.
How many amps is a 10 kVA transformer?
For a three-phase 400V system, a 10 kVA transformer carries approximately 14.4A per phase. Our 20-35kV SCB range starts at 50kVA and is designed for medium-voltage distribution networks with much higher power ratings.
How does a dry type transformer work?
A dry type transformer transfers energy through electromagnetic induction. The primary winding creates a magnetic flux in the silicon steel core, inducing voltage in the secondary winding. Epoxy resin provides the insulation medium, while air — natural or forced — dissipates heat.
How to tell if a transformer is dry type?
Identify a dry type transformer by the absence of an oil conservator, drain valve, or liquid-level gauge. The windings are either visible or sealed in solid resin, and the nameplate typically states “dry type,” “cast resin,” or “SCB” series designation.
