How to Choose the Right Oil-Immersed Transformer: The Ultimate Selection Guide

Key Factors for Selecting Oil-Immersed Transformers

1. Determine Your Power Requirements

✅ Calculate Transformer Capacity (kVA):

• Formula: Required kVA = Total Load (kW) / Power Factor (0.8-0.95)
• Example: 800kW load → 1000kVA transformer (800 ÷ 0.8)

✅ Voltage Levels (Primary & Secondary):

• Standard: 10kV/0.4kV, 35kV/10kV
• Custom options for industrial & renewable energy projects

2. Compare Efficiency & Losses

3. Choose the Right Cooling System

🔧 ONAN (Oil-Natural Air-Natural) – Best for ≤2000kVA, indoor use
🔧 ONAF (Oil-Natural Air-Forced) – Ideal for 2000-6000kVA, better cooling
🔧 OFAF (Oil-Forced Air-Forced) – Required for >6000kVA, heavy-duty

4. Special Requirements?

✔ Harmonic Environments? → Choose K-Factor ≥13 transformers
✔ Extreme Cold? → Use low-temperature oil (pour point < -45°C)
✔ Corrosive Areas? → Stainless steel tanks for long life

🔹 SEO Keyword Focus:

• “transformer K-factor for data centers”
• “best oil-immersed transformer for cold climates”

5. Verify Supplier Reliability

📌 Must-Have Certifications:

• ISO 9001 (Quality Management)
• IEC 60076 (International Safety Standard)
• Short-Circuit Test Reports

📌 Red Flags to Avoid:

• No real test data? → Risk of fake specs!
• Too cheap? → Higher losses = More electricity costs!

Free Downloadable Tools (For Better CTR)

📥 Transformer Sizing Calculator (Excel) – “Click to download free kVA calculator”
📥 Oil-Immersed Transformer Checklist (PDF) – *”10-point inspection guide”*