Success story Transmission utility

The transformer owner was notified by a service provider on the necessity of oil reclamation of 13 generator step-up transformers.

To a cost of 700 000 USD

- Owner consulted VPd for a second opinion

- DGA and Oil analyses provided clear answers


- One transformer was degassed for 3-4 months which made it possible to, during the Remaining life time assessment,  establish that it was a faulty transformer.

Savings taking correct actions:  700 000 USD.

Success story Power generation
Success story Pulp and paper

Remaining life time assessment of 32 generator step-up transformers

- 5 transformer flagged red

- 2 transformer flagged ”yellow” (end of technical life time), replacement

- 1 Indication of incorrect behavior


- One of the red market GSUs failed 18 months later

- Rest of the ”red transformers failed in the following 5 years.

Transformer indicating incorrect behavior failed in 2014. VPdiagnose were not aware it was a shell-type transformer which would have rendered it RED for failure.

Customer was notified that they need to replace all 15+ power transformers within 5 years for ageing reasons.

- Cost 6 MUSD SEK over 5 years

- Consulted us for standard diagnostics analysis  DGA and Oil sampling


- Analyses indicated of old transformers, but in good shape

- Life time extension activities were performed of a period of several years.

- All transformers are still in operation today

- Savings over 5 years 6 MSUD


Success story Aluminium smelter

Owner notified by service provider of need of oil reclamation on 14 transformers.

- Cost 800 000 USD

- Consulted VPdiagnoze for a second opinion based on the service company´s laboratories assessment.

- VPdiagnose assessment was that maybe ONE could be considered for oil reclamation….


- No reclamations were performed on any of the units.


Success story Water Conversion

Owner consulted VPdiagnose for diagnostics on 20 GSU and local transformers. 10- 230 kV transformers

- Wanted to have in-depth assessment on condition of desalination plant transformers.

- Remaining life time analysis


- All transformers in good health

- 5-15 years remaining life time

- Customer able to set up strategy and budget replacement and maintenance activities