1. Overview
Dry-type transformers use epoxy resin or Nomex® paper for insulation instead of mineral oil. They are ideal for indoor installations, high-fire-risk areas, and environmentally sensitive locations. This guide covers selection criteria per IEC 60076-11.
2. Key Selection Criteria
- Power rating (kVA): Match load + 20% margin for future expansion.
- Voltage ratio: Confirm primary (HV) and secondary (LV) voltages.
- Insulation class: F-class (155°C) for standard; H-class (180°C) for harsh environments.
- Cooling: AN (air natural) for <2500kVA; add AF (forced air) for higher loads.
- Enclosure: IP20 standard; IP23 for dust/humidity.
3. Recommended Models (Ziyao)
| Model | Power (kVA) | Voltage (kV) | Insulation | Cooling |
|---|---|---|---|---|
| SCB10 | 30–2500 | 10/0.4 | F-class | AN/AF |
| SCB11 | 30–2500 | 10/0.4 | F-class | AN/AF |
| SCB12 | 50–3150 | 10/0.4 | H-class | AN/AF |
| SCB13 | 50–3150 | 10/0.4 | H-class | AN/AF |
4. Installation Notes
Maintain minimum 300mm clearance for ventilation. Install on a non-combustible base. Ensure IP rating matches the environment.