ABSTRACT
In modern communities, due to increasing density of residential housing near substations and transformers, there is an increased prevalence of local ordinances specifying sound levels at commercial and residential property lines. It is appropriate that a good understanding of sources, measurement, and the mitigation options of sound energy radiated by transformers be developed for properly specifying sound levels in transformers. The demand for low sound levels has added new complexity to the measurement process of the radiated energy for transformers. The sound pressure that we hear or measure with a microphone is dependent upon the distance from the sound source and the acoustic environment in which the sound waves travel. A sound level meter is designed to respond to sound approximately the same way as the human ear and give objective, reproducible measurements of sound level. Cooling equipment usually influences the overall sound level of transformers of smaller MVA rating and low induction level design.
