1.1 This Indian Standard specifies methods of measuring and classifying the acoustic noise emitted by rotating electrical machines ( excluding small power machines and machines for traction vehicles ) on no-load.
1.2 A noise classification in terms of dB (A) sound power level is given. Methods are also included for correcting for the presence of pure tones.
1.3 Upper limits of dB (A) sound power level for machines rated up to 16 MW are given in Appendix D. Limits for larger machines are not at pre-sent given in this standard and should, therefore, be agreed to between the manufacturer and the purchaser.
1.4 Recommendations are included in Appendix B for methods of assess-ing noise from machines on load.
1.5 This standard covers measurements normally made in free field con-ditions. Where free-field conditions cannot, in practice, be achieved, recommendations are given in Appendix G for measurements made in semi-reverberant conditions.
IS 12065-1987 history
1987IS 12065-1987 Permissible noise level limits for rotating electrical machines