Audible sound levels in liquid-filled transformers

All transformers make some noise when operating, but certain regulations are in place to ensure they are built to operate as quietly as practically possible.

Written by:

Mac Spiller

March 12, 2020

How To's

All transformers have a slight hum (or buzz) when operating, but certain regulations are in place to ensure they are built to operate as quietly as practically possible.

Below are the latest NEMA TR-1 Average decibel ratings as of 2020.

Self-Cooled, Two Winding kVA Rating	Average Decibels (dB)
45-500	56
501-700	57
701-1000	58
1001-1500	60
1501-2000	61
2001-2500	62
2501-3000	63
3001-4000	64
4001-5000	65
5001-6000	66
6001-7500	67
7501-10000	68

Maddox Industrial Transformer liquid-filled padmount and substation transformers are built to the latest NEMA, IEEE, ANSI standards, and Department of Energy regulations.

Call us if you have any questions: 1-800-270-2011

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Audible sound levels in liquid-filled transformers

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