Dry-Type Transformers
Dry-Type Transformers
With the development of modern cities, fire and explosion-proof requirements have been introduced for distribution rooms, especially those in high-rise buildings and buildings with high fire ratings, in accordance with relevant fire safety regulations. Dry-type transformers, due to their inherent fire and explosion resistance, pollution-free operation, and maintenance-free design, are widely used in high-rise buildings, underground facilities, densely populated areas, and humid environments. Consequently, dry-type transformers have increasingly occupied a larger share of urban power distribution systems in recent years.
This series of products complies with national standards GB1094 “Power Transformers,” GB/T10228 “Technical Parameters and Requirements for Dry-Type Power Transformers,” and GB20052 “Energy Efficiency Limits and Energy Efficiency Grades for Power Transformers.”
Currently, this series of products is divided into three energy efficiency grades: SCB18 Level 1 (NX1), SCB14 Level 2 (NX2), and SCB12 Level 3 (NX3).
Structural Features
The high and low voltage coils of dry-type transformers are cast in a cast structure, offering advantages such as strong short-circuit resistance, minimal maintenance, high operating efficiency, compact size, and low noise. Dry-type transformers are often used in locations with strict fire and explosion-proof requirements.
The coil casting process utilizes static mixing, vacuum casting, and positive pressure, resulting in superior performance compared to vacuum casting without positive pressure.
Simulation analysis of the core model prevents core cavity resonance and effectively reduces noise. Lightning strike simulation analysis of the high-voltage coil model improves the product’s lightning resistance. Interlayer and intersegment field strengths are reduced to achieve low partial discharge.
The high and low voltage cast coils feature a thin resin structure, resist cracking, and provide excellent heat dissipation and low temperature rise.
The high and low voltage cast coils utilize H-class insulation material, offering strong overload capacity. They can operate at 110% load for extended periods using self-cooling or 150% load using forced air cooling.
Comprehensive temperature detection and protection systems are available. The intelligent signal temperature control system automatically detects and displays the operating temperature of each of the three-phase windings, automatically starts and stops the fan, and provides alarm and trip functions.
The product features an attractive appearance, compact size, minimal footprint, and low installation cost.
Technical Parameters
1. Operating Frequency: 50/60 Hz;
2. No-load Current: < 4%;
3. Withstand Voltage: 20,000 V/min without breakdown; Test Instrument: YZ1802 Withstand Voltage Tester (20 mA);
4. Insulation Class: F (Special classes available on request);
5. Insulation Resistance: ≥ 2 MΩ; Test Instrument: ZC25B-4 Megohmmeter ( 6. Connection: Y/Y, Δ/Y0, Yo/Δ, auto-coupling (optional);
7. Allowable Coil Temperature Rise: 100 K;
8. Cooling Method: Natural air cooling or temperature-controlled automatic cooling;
9. Noise Figure: ≤ 30 dB
Operating Environment
1.0 – 40°C, relative humidity <70%;
2. Altitude: No more than 2500 meters;
3. Avoid exposure to rain, moisture, high temperatures, extreme heat, or direct sunlight. The heat dissipation vents should be at least 40 cm away from surrounding objects;
4. Avoid operating in locations exposed to corrosive liquids, gases, dust, conductive fibers, or metal shavings;
5. Avoid operating in locations subject to vibration or electromagnetic interference;
6. Avoid long-term inverted storage and transportation, and avoid strong impact.