When is audible sound level an issue in the design?
Sound needs to be considered when transformers are located in close proximity to occupied areas. All energized transformers emanate sound due to the alternating flux in the core. The larger the kVA, the louder the audible noise. This normal sound emitted by the transformer can be a source of annoyance unless it is kept below acceptable levels. There are ways of minimizing sound emission as discussed in the HPS “Field Service Guide”.
HPS Transformers are built to meet the latest ANSI, CSA and UL standards. Audible noise is typically define by NEMA ST-20.