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Dry-Type Transformers Selection Guide: 7 Key Parameters for Perfect Matching (2024 Edition)
1. Core Electrical Parameters
- Rated Capacity (kVA) Calculation
- Formula:
Capacity = Total Load (kW) ÷ Power Factor (0.8~0.95) + 20% Margin - Example: Data center IT load 600kW → Select 800kVA (600÷0.9×1.2)
- Formula:
- Voltage Level Matching
- Standard distribution: 10kV/0.4kV
- Solar/Wind: 35kV/0.69kV (Custom required)
2. Insulation Class & Temperature Rise
| Insulation Class | Max. Temp Rise (°C) | Applications |
|---|---|---|
| Class F | 100 | Commercial Buildings |
| Class H | 125 | Steel/Chemical Plants |
| Class C | 150 | Marine/Military |
✅ Selection Tip:
- High-temp environments → Class H resin-encapsulated windings
- Low-noise requirements → Class F + <55dB design
3. Cooling Methods Comparison
| Type | Code | Capacity Range | Noise Level |
|---|---|---|---|
| Air Natural | AN | ≤1600kVA | ≤65dB |
| Forced Air | AF | 1600~2500kVA | ≤60dB |
| Composite | AN/AF | ＞2500kVA | Switchable |
⚠️ Warning:
- Avoid AF for basements (requires extra ventilation)
4. Special Environment Adaptation
- Humidity-Proof (IP54): Coastal/tropical areas
- Explosion-Proof (Ex d IIC T4): Oil & gas/mining
- High-Altitude (3000m+): Tibet/Andes projects
5. Energy Efficiency Standards
| Standard | No-Load Loss | Load Loss | Region |
|---|---|---|---|
| GB20052-2020 Tier 1 | Ultra-Low | Ultra-Low | China Mandatory |
| IEC 60076-23 | Super-Low | Super-Low | Export Projects |
💡 Cost-Saving Tip:
- Tier 1 costs 15% more but pays back in 2 years via electricity savings
6. Certification & Warranty Verification
✅ Must-Request Documents:
- Short-circuit withstand report (IEC 60076-5)
- Halogen-free certification (EN 50620)
- Seismic test report (Japan/California)
❌ Supplier Traps:
- “Equivalent copper” vs real copper windings (demand material test reports)
7. Selection Flowchart
