IEC 60034-9:2021

IEC 60034-9 ®
Edition 5.0 2021-10
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Rotating electrical machines –
Part 9: Noise limits
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IEC 60034-9 ®
Edition 5.0 2021-10
COMMENTED VERSION
INTERNATIONAL
STANDARD
colour
inside
Rotating electrical machines –

Part 9: Noise limits
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.160.01 ISBN 978-2-8322-4015-1

– 2 – IEC 60034-9:2021 CMV © IEC 2021
CONTENTS
FOREWORD . 3
INTRODUCTION . 2
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Methods of measurement . 8
5 Test conditions . 8
5.1 Machine mounting . 8
5.1.1 Precautions . 8
5.1.2 Resilient mounting . 9
5.1.3 Rigid mounting . 9
5.2 Test operating conditions . 9
6 Sound power level limits . 9
7 Determination of noise increments caused by converter supply .
7 Determination of sound pressure level . 10
8 Declaration and verification of sound power values. 12
Annex A (informative) Typical values for measurement surface index . 18
Annex B (informative) Information on typical noise increments caused by converter supply . 19
Bibliography . 22
List of comments . 23
Figure B.1 – Frequency spectrum of the currents at the output terminals of a 6‑pulse
block-type current-source converter f = 50 Hz . 19
Figure B.2 – Frequency spectrum of the voltages at the terminals of a type A
voltage-source converter (characterized by pronounced spikes close to the switching
frequency and its multiples) f = 50 Hz, f = 3 kHz . 19
1 s
Figure B.3 – Frequency spectrum of the voltages of a type B voltage-source converter
= 50 Hz, f
(characterized by a broad voltage spectrum without pronounced spikes) f
1 s
average = 4,5 kHz . 20
Table 1 – Maximum A-weighted sound power level, L in dB, at no-load (excluding
WA
motors according to Table 2 and Table 3) (Method of cooling, IC code, see IEC 60034-
6, Method of protection, IP code, see IEC 60034-5) . 14
Table 2 – Maximum A-weighted sound power level, LWA in dB, at no-load, 50 Hz,
sinusoidal supply (for single speed three-phase cage induction motors IC411, IC511,
IC611) . 15
Table 3 – Maximum A-weighted sound power level, L in dB, at no-load, 60 Hz,
WA
sinusoidal supply (for single speed three-phase cage induction motors). 16
Table 4 – Maximum Expected increase, over no-load condition, in A-weighted sound power
levels, ΔL in dB, for rated load condition (for motors according to Table 2 and Table 3) . 17
WA
Table A.1 – Typical values for measurement surface index for the conversion from sound
power level to sound pressure level based on using parallelepiped measurement surface
according to ISO 3744 . 18
Table B.1 – Resonance frequencies of vibration mode r . 20
Table B.2 – Increments of A-weighted noise values . 20

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ROTATING ELECTRICAL MACHINES –

Part 9: Noise limits
FOREWORD
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This commented version (CMV) of the official standard IEC 60034-9:2021 edition 5.0
allows the user to identify the changes made to the previous IEC 60034-9:2003
+AMD1:2007 CSV edition 4.1. Futhermore, comments from IEC TC 2 experts are provided
to explain the reasons of the most relevant changes.
A vertical bar appears in the margin wherever a change has been made. Additions are in
green text, deletions are in strikethrough red text. Experts' comments are identified by a
blue-background number. Mouse over a number to display a pop-up note with the
comment.
This publication contains the CMV and the official standard. The full list of comments is
available at the end of the CMV.

– 4 – IEC 60034-9:2021 CMV © IEC 2021
IEC 60034-9 has been prepared by IEC technical committee 2: Rotating machinery. It is an
International Standard.
This fifth edition cancels and replaces the fourth edition, published in 2003 and its
amendment 1, published in 2007. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) In Table 2 and Table 3 cooling methods IC01, IC11, IC21 and IC31, IC71, IC81 are now
covered.
b) This edition adds Table 3 for 60 Hz machines, whereas Table 2, which covers only 50 Hz
machines, has no change in levels.
c) In Table 3, grade A is added to harmonize the highest levels seen in IEC and NEMA,
whereas grade B was added to harmonize the lowest, more restrictive levels seen in IEC
and NEMA.
d) The clause “Determination of noise increments caused by converter supply” has been
shifted to Annex B and renamed “Information on typical noise increments caused by
converter supply”
The text of this International Standard is based on the following documents:
FDIS Report on voting
2/2064/FDIS 2/2069/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
A list of all parts in the IEC 60034 series, published under the general title Rotating electrical
machines, can be found on the IEC website.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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INTRODUCTION
Acoustic quantities can be expressed in sound pressure terms or sound power terms. The use
of a sound power level, which can be specified independently of the measurement surface and
...