What is the sound level of a dry type transformer? What causes such sound?
Sound is produced in transformers as a result of flux variations in the iron core. Sound is caused by physical movement of pieces in the core, as well as elongation and contraction of iron during each AC cycle. The National Electrical Manufacturers Association (NEMA) has set up the following audible sound level limits for dry type transformers.
The sound level of a dry type transformer is the result of the variations of flux in the iron core. This can be due to physical movement of pieces of core or lamination and the elongation and contraction of iron during each cycle of the alternating current used. The National Electrical Manufacturers Association (NEMA) has set up the following audible sound level limits for dry type transformers: A decibel is the unit of measure of sound level or noise. Decibels are expressed as a logarithmic function. Therefore, the noise or sound level does not increase in proportion to the number of decibels. Fifty-five decibels is about the level of noise you would experience in a large quiet automobile at high cruise speed.
