IS 12065 : 1987 Permissible limits of noise level for rotating electrical machines

1 Scope

1.1 This Indian Standard specifies methods of measuring andclassifying the acoustic noise emitted by rotating electricalmachines (excluding small power machines and machines for tractionvehicles) on no-load.

1.2 A noise classification in terms of dB (A) sound power levelis given. Methods are also included for correcting for the presenceof pure tones.

1.3 Upper limits of dB (A) sound power level for machines ratedUP to 16 MW are given in Appendix D. Limits for larger machines arenot at present given in this standard and should, therefore, beagreed to between the manufacturer and the purchaser.

1.4 Recommendations are included in Appendix B for methods ofassessing noise from machines on load.

1.5 This standard covers measurements normally made in freefield conditions. Where free-field conditions cannot, in practice,be achieved, recommendations are given in Appendix G formeasurements made in semi-reverberant conditions.

2 References

IS 2 :1960 Rules for rounding offnumerical values

IS 4758 : 1968Methods of measurement of noise emitted by machine

IS 6098 : 1971Methods of measurement of the airborne noise emitted byrotating electrical machinery

IS 9779 : 1981Specification for sound level meters