IS 12065 : 2025 Permissible Limits of Noise Levels for Rotating Electrical Machines (IEC 60034-9 : 2021, MOD)
(Superseding IS 4758 : 1968)
1 SCOPE
1.1 This standard specifies that:
a) Test methods for the determination of sound power level of rotating electrical machines;
b) Maximum A-weighted sound power levels for factory acceptance testing of networksupplied, rotating electrical machines in accordance with IS 15999 (Part 1)/IEC 60034-1, having methods of cooling according to IS 6362/IEC 60034-6 and degrees of protection according to IS/IEC 60034-5, and having the following characteristics:
1) Standard design, either a.c. or d.c., without additional special electrical, mechanical, or acoustical modifications intended to reduce the sound power level;
2) Rated output from 1 kW (or kVA) up to and including 5 500 kW (or kVA); and
3) Rated speed not greater than 3 750 min–1.
1.2 Excluded are noise limits for a.c. motors supplied by converters. For these conditions see Annex C for guidance.
1.3 The object of this document is to determine maximum A-weighted sound power levels, LWA in decibels, dB, for airborne noise emitted by rotating electrical machines of standard design, as a function of power, speed and load, and to specify the method of measurement and the test conditions appropriate for the determination of the sound power level of the machines to provide a standardized evaluation of machine noise up to the maximum specified sound power levels. This document does not provide correction for the existence of tonal characteristics.
1.4 Sound pressure levels at a distance from the machine may be required in some applications, such as hearing protection programs. Information is provided on such a procedure in 7 based on a standardized test environment.
NOTES
1 This document recognizes the economic reason for the availability of standard noise-level machines for use in non-critical areas or for use with supplementary means of noise attenuation.
2 Where sound power levels lower than those specified in Table 1, or Table 2 are required, these are agreed between the manufacturer and the purchaser, as special electrical, mechanical, or acoustical design may involve additional measures.
2 REFERENCES
The standards listed at Annex A contain provisions, which through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards.
| IS No./Other Publications | Title |
| IS/ISO 4871 : 1996 | Acoustics - Declaration and verification of noise emission values of machinery and equipment |
| IS 6362 : 1995/IEC 60034-6 : 1991 | Designation of methods of cooling of rotating electrical machines (first revision) |
| IS/IEC 60034-5 : 2000 | Rotating electrical machines: Part 5 Degrees of protection provided by the integral design of rotating electrical machines (IP code) - Classification |
| IS 15999 (Part 1) : 2021/IEC 60034-1 : 2017 | Rotating electrical machines: Part 1 Rating and performance |
| ISO 3741 : 2010 | Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Precision methods for reverberation test rooms |
| ISO 3743-1 : 2010 | Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering methods for small, movable sources in reverberant fields - Part 1: Comparison method for a hard-walled test room |
| ISO 3743-2 : 2018 | Acoustics - Determination of sound power levels of noise sources using sound pressure - Engineering methods for small, movable sources in reverberant fields - Part 2: Methods for special reverberation test rooms |
| ISO 3744 : 2010 | Acoustics - 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 |
| ISO 3745 : 2012 | Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Precision methods for anechoic rooms and hemi-anechoic rooms |
| ISO 3746 : 2010 | Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Survey method using an enveloping measurement surface over a reflecting plane |
| ISO 3747 : 2010 | Acoustics - Determination of sound power levels and sound energy levels of noise sources using sound pressure - Engineering/ survey methods for use in situ in a reverberant environment |
| ISO 9614-1 : 1993 | Acoustics - Determination of sound power levels of noise sources using sound intensity - Part 1: Measurement at discrete points |
| ISO 9614-2 : 1996 | Acoustics - Determination of sound power levels of noise sources using sound intensity: Part 2 Measurement by scanning |