Transformer Oil - Quantities to Stock

the minimum quantity to stock is the oil quantity in the largest transformer

alternatively, u can average oil consumption for te past two years monthwise and arrive at a reasonable fig

E ANANDAN

WWW.CHOLARISK.COM

Thanks a lot Mr. E.ANANDAN for the valuable information. Regards.

Regular Transformer Oil Maintenance requires oil analysis for moisture, the presence of explosive gases, partial discharge components, thermal discharge components, corrosive compounds, a test for presence of corrosion inhibitor in oil and other factors such as color, viscocity, di-electric test, etc. Test requirements are covered under IEC 60599:2002 or IEE std C57.106.2002. PD, D1, D2, T1, T2, T3 are all described therein. Oil Maintenance should occur at regularly scheduled intervals. Kelman's Transport-X portable unit is useful for regular field site testing or you can mount permanent units on your transformers. You should also have Nitrogen gas to ensure a N2 positive pressure head on top of the oil inside the tanks. If you have Load Tap Changers, these need to be checked on a regular basis and inspected about every 5 years. If you have low oil or leaks, these need to be repaired when you shutdown (clear) the transformer bank. When the leaks are repaired, then additional oil is added. This oil needs to be tested PRIOR to it's addition into the transformer. The oil also needs to be of the same type that is in the transformer. Generally, if the oil in the transformer is contaminated, you perform a HORI on the oil, which is a Hot Oil Re-inhibiting process. A mobile oil processing system with a portable generator is brought out to site and the oil is processed by de-gassification, filtered in a closed loop and returned to the transformer "Hot". During this time an inhibitor is added into the transformer's insulating oil to slow and stabilize the aging and deterioration process of the transformer oil. Oil produces oxidation by-products such as Acid and Sludge that attack the paper insulation system in the transformer. The oil inhibitor slows this attack.

When you keep oil IN-STOCK, you must consider the age of the oil. The oil is only "good" for a certain amount of time. After that time, it must be re-tested prior to insertion into the transformer tank. Keeping oil in-stock for years to just throw into a transformer is NOT a good solution. Oil should be ordered in concert with an excellent transformer maintenance program. If you do not have a Transformer oil maintenance program, I suggest you contact your local DOBLE field engineer representative to assist you in setting one up. The oil ordering and oil maintenance should start at the same time.

Another problem is once you order the oil, how do you get it into the transformer? You need a mobile oil processing system which consists of a towed trailer with secondary containment, barrels, hoses, portable generator, oil spill rags, oil adsorbent material, brooms, shovels, first aid kit, safety glasses, oil ppe, etc. You will need some way to insert the oil safely into the transformer and the after the insertion a way to pressurize the tank with a nitrogen blanket.

There is quite a bit more involved in ordering oil for your transformers than just ordering oil.

Thanks a lot "Gizmo787" for additional lot of information. We have been doing regular Tx maint. and keeping records.Your information is cetainly valuable for us and we will add to our schedules whatever is left. Thanks once more & Regards