Hermetically sealed oil transformers are normally manufactured with a sealed tank equipped with fins that allow for the expansion at the said temperature variations. The tightness of the tank is up to 0.5 Bar. This type of transformer is the most widely used globally. In the hermetically sealed transformer, the oil does not come into contact with air and its electrical properties are therefore not compromised, ensuring a long life span of the transformer. For power ratings exceeding 3150kVA, or in case of a transformer with radiators, the transformer can still be hermetically sealed by means of a nitrogen cushion. These type of distribution transformers can be designed and manufactured bespoke with top or side connections.
Oil: Mineral, silicone, ester or vegetable type
Accessories: Corrugated Wall, Pressure Relief Valve with Contact, Air Drier Including Silica Gel, Magnetic Oil Level Indicator with Contact, Lifting Lugs and Eyes, Fixing Rings, Earthing Terminals, Terminal Box.
Voltage Class: 1.1kV – 52kV
Material temperature classes: A, F