Oil-Immersed Transformer

In an oil-immersed (oil-filled) transformer the core and windings sit in a welded steel tank filled with insulating oil. Heat from the coil and core passes into the oil and from there to the cooling medium, which keeps the transformer temperature down.

Depending on capacity, units are naturally cooled or use forced-air cooling. They suit outdoor and dedicated substation rooms.

Where it is used

• Outdoor factory and building substations
• Separate substation rooms with an oil pit
• Large ratings where oil cooling is efficient
• Industrial parks and commercial complexes

How to choose

• kVA rating from your connected load and future growth.
• Voltage ratio: 11/0.415 kV or 33/0.415 kV.
• Cooling: ONAN (natural) or ONAF (forced air).
• Losses and tap changer for running cost and voltage control.
• Location: safe clearances, oil pit and fire protection.

Why buy from Unique Quality Engineering

We supply substation equipment and handle installation, testing and commissioning of the complete substation, so one team is responsible from design to energising.

Frequently asked questions

Oil or dry type transformer – which is better?

Oil transformers cost less and suit outdoor or separate rooms. Dry type suits indoor locations where fire safety matters most. See our comparison.

Does an oil transformer need maintenance?

Yes. Check oil level and test the oil regularly, and keep the breather and radiators in good condition.

Do you install the transformer?

Yes. We install, test and commission the transformer with the HT and LT panels.

Need a price for an oil-immersed transformer? Request a quotation with the rating and quantity, or call or WhatsApp +8801992-389515.