Product Overview
The non-encapsulated dry-type transformer (also known as open-wound or air-insulated dry-type transformer) is a safe, environmentally friendly, and cost-effective power conversion solution for indoor distribution systems. Unlike encapsulated (cast resin) dry-type transformers, the non-encapsulated design features open windings with high-temperature insulation materials (such as Nomex® aramid paper or glass-fiber reinforced insulation), allowing direct air circulation for cooling. This design provides excellent heat dissipation, easy visual inspection, and simplified repair and maintenance.
The product utilizes high-quality copper or aluminum windings with advanced vacuum pressure impregnation (VPI) technology, ensuring superior electrical insulation, mechanical strength, and moisture resistance. It is widely applied in industrial facilities, commercial buildings, infrastructure projects, and renewable energy systems where cost efficiency, maintainability, and environmental safety are key considerations.

Key Features
1. Fire Safety & Environmental Protection
• No insulating oil used – eliminates oil leakage, fire, and explosion risks
• Flame-retardant, self-extinguishing insulation materials meet international fire safety standards
• Fully recyclable and environmentally friendly – zero pollution to the surrounding environment
• No toxic gas emissions even under fault conditions
2. Low Loss & High Energy Efficiency
• Core made of high-quality cold-rolled grain-oriented silicon steel, significantly reducing no-load losses
• Optimized winding design minimizes stray losses and eddy current losses
• Available in multiple energy efficiency grades to meet diverse project requirements
3. Superior Short-Circuit Withstand Capability
• High-strength conductor materials and robust winding structure withstand short-circuit forces effectively
• Vacuum pressure impregnation (VPI) process provides excellent coil rigidity and adhesion
• Glass-fiber reinforced insulation enhances mechanical strength and impact resistance
4. Excellent Overload Capacity & Thermal Performance
• Open-winding design provides superior heat dissipation with direct air cooling
• High-temperature insulation materials (Class F or H) allow for higher overload capacity
• Lower temperature rise compared to encapsulated designs under the same load conditions
5. Easy Inspection & Maintenance
• Open winding structure allows visual inspection of coils without disassembly
• Simple cleaning and maintenance – dust accumulation can be easily removed with compressed air
• Individual coil replacement possible without replacing the entire transformer unit
• No specialized tools or equipment required for routine maintenance
6. Low Noise Operation
• High-quality core material with optimized flux density selection
• Advanced core joint technology minimizes magnetostriction noise
• Vibration-damping design reduces operational vibration and noise transmission

Technical Specifications
Rated Power: 30kVA ~ 10,000kVA and above
HV Voltage: 6kV, 6.3kV, 10kV, 10.5kV, 11kV, 20kV, 35kV (customizable)
LV Voltage: 0.4kV, 0.415kV, 0.433kV, 0.69kV (customizable)
Vector Group: Dyn11, Yyn0, Yzn11 (customizable)
Tapping Range: ±5% or ±2×2.5% (customizable)
Short-Circuit Impedance: 4% ~ 6% (depending on capacity rating)
Frequency: 50Hz / 60Hz
Cooling Method: AN (Air Natural) / AF (Air Forced)
Insulation Class: F-Class (155°C) or H-Class (180°C)
Temperature Rise Limits: 100K (F-Class) / 125K (H-Class)
Insulation System: Nomex® aramid paper or glass-fiber reinforced insulation with VPI treatment
Core Structure: Three-phase three-column or five-column structure

Model Series
SG(B)10-(30-10000)/10kV – Non-Encapsulated Dry-Type Transformer (Standard series)
SG(B)11-(30-10000)/10kV – Non-Encapsulated Dry-Type Transformer (Enhanced efficiency series)
SG(B)13-(30-10000)/10kV – Non-Encapsulated Dry-Type Transformer (High efficiency series)

Applications
• Industrial Facilities: manufacturing plants, steel mills, cement factories, chemical plants
• Commercial Buildings: shopping malls, office buildings, hotels, exhibition centers
• Public Facilities: hospitals, schools, museums, sports stadiums
• Infrastructure: airports, railway stations, subway systems, ports
• Renewable Energy: wind power, photovoltaic, and energy storage systems (indoor installations)
• Power Systems: substations, power distribution centers, auxiliary power supply

Compliance Standards
• IEC 60076 Series
• GB 1094 – Power Transformers
• GB/T 10228 – Technical Parameters and Requirements for Three-Phase Dry-Type Distribution Transformers
• GB 20052-2020 – Energy Efficiency Limits and Energy Efficiency Grades for Power Transformers
• GB/T 22072 – Technical Specification for Dry-Type Power Transformers

Why Choose Us
• Cost-Effective: economical design with excellent performance – the most budget-friendly dry-type transformer solution
• Easy Maintenance: open-windings for visual inspection and simplified cleaning – no disassembly required
• Fire-Safe & Environmentally Friendly: oil-free, flame-retardant, and fully recyclable design
• Excellent Overload Capacity: superior heat dissipation and high-temperature insulation for demanding applications
• Professional Manufacturing: years of R&D and production experience in dry-type transformer industry
• Quality Assurance: full-process quality control with rigorous inspection and testing
• Customization Services: flexible customization of capacity, voltage, vector group, and other parameters
• Comprehensive After-Sales: technical support, installation guidance, and long-term maintenance services