Power and distribution transformer routine inspection (all voltage classes)
Estimated duration: 1 - 2 hours • Frequency: monthly (critical) / quarterly (distribution)
Asset Details
| # | Inspection Item | OK / Fail / NA | Notes |
|---|---|---|---|
| Oil System and Insulating Fluid | |||
| 1 | Main tank oil level gauge reading within normal range | ☐ ☐ ☐ | |
| 2 | Conservator oil level (if fitted) within normal range | ☐ ☐ ☐ | |
| 3 | Oil colour and clarity through sight glass (no darkening or particles) | ☐ ☐ ☐ | |
| 4 | No oil leaks at gaskets, drain valves, radiator joints or pipe fittings | ☐ ☐ ☐ | |
| 5 | Last DGA results reviewed, no gases trending above normal limits | ☐ ☐ ☐ | |
| Bushings and Connections | |||
| 6 | HV bushings free from cracks, chips, contamination and flashover marks | ☐ ☐ ☐ | |
| 7 | LV bushings free from cracks, chips, contamination and flashover marks | ☐ ☐ ☐ | |
| 8 | No oil weep at bushing gasket seals | ☐ ☐ ☐ | |
| 9 | Cable terminations tight, no signs of overheating or discolouration | ☐ ☐ ☐ | |
| Tap Changer | |||
| 10 | Tap changer type and current tap position recorded | ☐ ☐ ☐ | |
| 11 | OLTC operation counter reading noted (if on-load type) | ☐ ☐ ☐ | |
| 12 | OLTC compartment oil level within range (if applicable) | ☐ ☐ ☐ | |
| 13 | Drive mechanism operates smoothly, no unusual noise or excessive travel | ☐ ☐ ☐ | |
| Cooling System | |||
| 14 | All cooling fans operational, rotating in correct direction | ☐ ☐ ☐ | |
| 15 | Oil circulation pumps running (if forced-oil cooling) | ☐ ☐ ☐ | |
| 16 | Radiator fins clean and unobstructed by debris or vegetation | ☐ ☐ ☐ | |
| 17 | Oil temperature indicator (OTI) reading within normal range | ☐ ☐ ☐ | |
| 18 | Winding temperature indicator (WTI) reading within normal range | ☐ ☐ ☐ | |
| Protection and Controls | |||
| 19 | Buchholz relay status normal (no gas accumulation or trip) | ☐ ☐ ☐ | |
| 20 | Pressure relief device (PRD) intact, no sign of operation | ☐ ☐ ☐ | |
| 21 | Sudden pressure relay status normal (if fitted) | ☐ ☐ ☐ | |
| 22 | Overcurrent and differential protection relays status normal | ☐ ☐ ☐ | |
| 23 | Temperature alarm set points verified and functional | ☐ ☐ ☐ | |
| Earthing and External Condition | |||
| 24 | Main earth connection secure, low resistance, no corrosion | ☐ ☐ ☐ | |
| 25 | Neutral earth connection intact and undamaged | ☐ ☐ ☐ | |
| 26 | Tank, radiators and paint free from corrosion and physical damage | ☐ ☐ ☐ | |
| 27 | Oil containment bund intact, no accumulated oil or rainwater | ☐ ☐ ☐ | |
| 28 | Fire protection system (deluge, foam) status indicator normal | ☐ ☐ ☐ | |
| 29 | Vermin guards and cable entry seals intact | ☐ ☐ ☐ | |
| 30 | Warning signage, voltage labels and danger signs legible and present | ☐ ☐ ☐ | |
Operating Parameters Recorded
Notes / Defects Identified
Next Inspection Due
Inspector
Electrical Supervisor