DRY-OUT EXAMPLES
Water reduction will take several weeks depending on the size and oil volume of the transformer, the volume of water in the cellulose insulation and the operating load temperature. The examples should provide a good indication. The TTAS example gives a Filter cost for water volume removed.
Data recorded allows a detailed understanding of the water migration rates from cellulose at various temperature profiles. Examples show the total water removed over the period of filtering, and the water from cellulose migration trends. Both TTA1 and TTP1 have been re-analysed following the water reduction and the improvements detailed.
Case Study 1
The following two examples are from the Analysis and water reduction on a group of seven 40yr old 10 mva transmission transformers at one utility. The summary compares the water from cellulose migration rates at various load temperatures:
TTA S – Summary of seven identical 10 Mva transformers - TTA 4 – 10 mva 3 ph Network transformer over 40 days
Case Study 2
A 40yr old water cooled generation transformers. It shows the superior water from oil removal performance of the Trojan.
Case Study 3
Before and after Analysis, 5.25 litres of water was removed from a 40yr old 15 mva transmission transformer with significant improvement.