Meaningful Measurements to Assess Transformer Noise


  • Henk de Haan dBA Noise Consultants Ltd
  • Virgini Senden dBA Noise Consultants Ltd


Electric transformers are situated where electric power is used – frequently, close to people. Due to their hum and the noise of cooling fans they may cause intrusive noise levels.

A noise impact assessment (NIA) is therefor a useful tool to predict noise levels near third party stakeholders, to assess their acceptability and to prevent future noise problems. The sound power level (PWL) provides necessary information to be used in such an assessment or compare transformers. Typically, the PWL for transformers is calculated from measurements using standards such as IEEEI standard C57.12.90-2010, “IEEE Standard Test Code for Liquid-Immersed Distribution, Power and Regulating Transformers”. That standard requires an elaborate number of individual measurements around a transformer and results in a single-number PWL, without taking potential directivity into account. The method may therefore not be the most suitable to provide the necessary data for the purpose of assessing the noise impact from transformers. This paper aims to compare the measurement procedure and results according to IEEEI standard C57.12.90-2010 to other relevant standards such as ISO 3744:2010 “Determination of sound power levels and sound energy levels of noise sources using sound pressure – Engineering methods for an essentially free field over a reflecting plane” or measurements at some distance, assuming the transformer as a point source.

Henk de Haan, Eur. Ing. INCE Bd. Cert.

dBA Noise Consultants Ltd

(403) 836 8806




How to Cite

de Haan H, Senden V. Meaningful Measurements to Assess Transformer Noise. Canadian Acoustics [Internet]. 2016 Aug. 25 [cited 2021 Oct. 19];44(3). Available from:



Proceedings of the Acoustics Week in Canada