When dry-type cast resin or oil-filled electrical transformers are in operation, they emit a characteristic noise from the vibrations of the magnetic laminations (magneto constriction) they contain This vibration comes from the 50 Hz alternating current that flows through them, characterising a fundamental vibration frequency of 100 Hz and several corresponding vibration harmonics.
Depending on the electrical charge used, the design and the age of the transformer, these vibrations can increase over time. Moreover, depending on the place of installation (car park, basement of a building, roof, etc.) these vibrations can cause the structure to vibrate in resonance.
Sanervib transformer silentblocks are specifically designed to reduce vibrations and therefore the noise produced by the transformers.