This practical guide shows you how to complete a signed, QR-verified Power & Distribution Transformer Inspection certificate in OhmCert Module #07 and how to troubleshoot non-compliant readings on site.
1. Step-by-Step OhmCert UI Workflow
- Open Module #07: Navigate to Power & Distribution Transformer Inspection from the Dashboard.
- Load a 1-Click Standard Annex Preset: Open the blue Standard Annex banner at the top and click a preset (such as "1000 kVA, 34.5 / 0.4 kV Oil Distribution Transformer") to populate target limits automatically.
- Enter Your Field Measurements: Fill in the measured inputs (Rated Capacity, Rated HV Voltage, Measured Loading, Top Oil / Winding Temperature, Ambient Temperature, Nameplate Temperature Rise Class, HV-LV Insulation Resistance, Turns Ratio (TTR) Deviation, Winding Resistance Imbalance, Oil Dielectric Breakdown (ASTM D877), Dissolved Gas TDCG). Blank inputs stay neutral
PENDING. - Complete the 18-Point Checklist: Grade each item, attach photos if needed, and export the SHA-256 signed PDF certificate.
2. Worked Numerical Field Case Study
Scenario: 1000 kVA, 34.5 / 0.4 kV Oil Distribution Transformer (IEC 60076 / TR) — Standard 34.5 kV MV/LV industrial distribution transformer (65 degC rise)..
- Rated Capacity:
1000 kVA - Rated HV Voltage:
34.5 kV - Nameplate Temperature Rise Class:
65 degC rise - Ambient Temperature:
25 degC
3. Engineering Troubleshooting: Corrective Actions When a Reading Fails
- Perform online vacuum dehydration and fuller's earth oil regeneration if BDV < 30 kV or moisture exceeds 25-35 ppm.
- Apply Duval Triangle 1 / Rogers Ratios on Condition 3-4 DGA results and schedule internal borescope/SFRA inspection.
- Clean and re-torque off-circuit/on-load tap changer (OLTC) contacts if TTR or winding DC resistance imbalance exceeds 0.5-1.0%.
→ Try This Worked Example Live in Module #07 (Transformer Inspection)