SG(B) Series Non-Encapsulated H Class Dry Type Transformer

1. What is the difference between SG(B) and SC(B) dry type transformers?
SG(B) Series Non-Encapsulated Dry Type Transformer adopts an open winding structure, allowing direct airflow through the windings for better heat dissipation and easier maintenance.
SC(B) Series uses epoxy resin cast windings, providing stronger protection against moisture, dust, and pollution.
SG(B) is commonly considered for high-temperature, heavy-load, and industrial applications, while SC(B) is often selected for environments requiring stronger insulation protection.

2. What does H Class insulation 180℃ mean?
The 180℃ value represents the heat resistance class of the insulation system.
It does not mean that the transformer winding should operate continuously at 180℃. Actual operating temperature depends on load conditions, ambient temperature, cooling method, and design limits.

3. Where can SG(B) Series transformers be used?
The transformer is suitable for industrial indoor power distribution applications, including metallurgy, steel, mining, cement, petrochemical, rail transit, marine, and port projects.
High temperature, high altitude, and special environmental conditions should be confirmed during the design stage.

4. Is the open winding structure more sensitive to dust and moisture?
Yes.
The open structure improves cooling performance and maintenance accessibility but requires proper environmental evaluation.
For dusty, humid, corrosive, or condensation-prone environments, suitable protection measures, cleaning schedules, and environmental designs should be considered.

5. What maintenance is required?
Routine maintenance includes:
Cleaning windings and ventilation channels
Checking connections and grounding
Inspecting insulation surfaces and clamping parts
Checking fans and sensors
Reviewing temperature records
Performing electrical inspections according to site requirements
No oil sampling or oil replacement is required.

6. How are high temperature and high altitude projects handled?
High temperature and high altitude conditions affect heat dissipation and insulation coordination.
The design should consider temperature rise, insulation distance, cooling method, ventilation conditions, and other project-specific requirements.

H Class Insulation and High Temperature Capability
The H Class Dry Type Transformer uses an insulation system with a heat resistance level of 180℃.
The 180℃ rating represents the insulation heat resistance class and does not mean the winding should continuously operate at this temperature. Actual operating temperature depends on ambient conditions, temperature rise limits, hotspot temperature, load profile, and cooling design.
This structure provides additional thermal design capability for high-temperature and heavy-load operating environments.

Open Winding Structure and Efficient Heat Dissipation
The Non-Encapsulated Dry Type Transformer adopts an open winding structure, allowing air to directly pass through the winding surface and ventilation channels.
Compared with Cast Resin Dry Type Transformers, the open structure improves natural airflow and makes cleaning and visual inspection easier during maintenance.
The transformer supports AN natural cooling under normal conditions and optional AF forced air cooling with temperature-controlled fan operation for applications requiring enhanced heat dissipation.

Mechanical Strength and Short-Circuit Performance
The windings can be manufactured with copper or aluminum conductors and combined with glass fiber reinforced insulation, impregnation processes, and mechanical clamping structures.
The short-circuit withstand capability depends on electromagnetic design, winding structure, support system, and manufacturing consistency. Final performance shall be confirmed according to approved technical documents and agreed testing requirements

Lower Maintenance Requirements and Environmental Adaptability
The SG(B) Series Dry Type Transformer does not contain insulating oil, eliminating oil sampling, oil filtration, and oil leakage management.
The open structure allows easier cleaning and inspection, making it suitable for industrial environments where maintenance accessibility and continuous operation are important.

Complete Transformer Product Capability
Jiangsu Xinxin Electric provides transformer solutions including:
SG(B) Series Non-Encapsulated H Class Dry Type Transformer
Cast Resin Dry Type Transformers
Dry Type Transformers
Oil Immersed Transformers
Box substations
Related power distribution equipment
This allows EPC contractors, OEM customers, distributors, and system integrators to coordinate different transformer solutions through one supplier.

Manufacturing and Quality Control
Production is managed through controlled manufacturing processes, including:
Technical and contract review
Incoming material inspection
Core processing and assembly
Winding manufacturing
Impregnation and curing process control
Transformer assembly
Routine testing and final inspection
Key materials including silicon steel sheets, copper/aluminum conductors, H Class insulation materials, glass fiber materials, impregnation materials, and accessories are inspected according to technical requirements.

Quality control covers:
Material verification
Winding dimensions and connections
Insulation distance
Mechanical clamping
Temperature control wiring
Electrical routine testing
Final documentation review

Engineering Documentation and Export Support
Jiangsu Xinxin Electric supports international projects with technical documents including:
Technical data sheets
Assembly drawings
Electrical drawings
Nameplates
Test reports
Operation manuals
Packing documents
Documents can be prepared according to IEC, GB, customer specifications, and project approval requirements.