FprEN IEC 60034-14:2026

• Status: Not Published
• Publication Date: 06-Dec-2026
• ICS: 29.160.01 - Rotating machinery in general
• Technical Committee: CLC/TC 2 - Rotating machinery
• Current Stage: 5060 - Voting results sent to TC, SR - Formal Approval
• Start Date: 04-Sep-2026
• Completion Date: 04-Sep-2026
• Ref Project: kSIST FprEN IEC 60034-14:2026 - Rotating electrical machines - Part 14: Mechanical vibration of certain machines with shaft heights 56 mm and higher - Measurement, evaluation and limits of vibration severity

• Revises: EN IEC 60034-14:2018 - Rotating electrical machines - Part 14: Mechanical vibration of certain machines with shaft heights 56 mm and higher - Measurement, evaluation and limits of vibration severity
• Effective Date: 03-Jun-2025

FprEN IEC 60034-14:2026 is the CENELEC draft of IEC 60034-14 for rotating electrical machines with shaft heights 56 mm and higher. It specifies factory acceptance vibration test procedures, evaluation methods, and vibration limits for certain DC and three-phase AC machines when they are tested uncoupled from any load or prime mover. The document is aimed at manufacturers, test laboratories, suppliers, customers, and buyers who need a common way to measure and judge machine vibration.

What does FprEN IEC 60034-14:2026 specify?

FprEN IEC 60034-14:2026 specifies how to measure, evaluate, and limit mechanical vibration for certain rotating electrical machines in factory tests. It applies to DC and three-phase AC machines with shaft heights 56 mm and higher, rated output up to 50 MW, and operating speeds from 120 min^-1 to 15 000 min^-1.

The document is organized into Clauses 1 to 9, plus a bibliography. Its main topics are scope, normative references, terms and definitions, measurement quantities, measurement equipment, machine mounting, measurement conditions, vibration limits at the bearing housing, and limits for relative shaft vibration.

The scope is focused on machines tested under specified conditions. It is not intended for machines mounted in situ, and it also excludes several machine types named in Clause 1, so users can quickly tell whether the standard fits a factory test or whether another document is needed for site measurements.

What are the key requirements of FprEN IEC 60034-14:2026?

Measure the right vibration quantities

Clause 4 requires vibration displacement and vibration velocity at the bearings, together with relative shaft vibration displacement near the bearings. For bearing vibration, the criterion is the broadband RMS value, which matters because the test result must reflect the overall vibration level rather than a narrow frequency spike.

For induction motors with twice-slip-frequency beating, Clause 4 gives a way to derive the decisive RMS value from the maximum and minimum readings. In practice, this means the measuring system must capture the peak and low points reliably, not just a single short sample.

Use suitable equipment

Clause 5 requires measuring equipment with flat response over 10 Hz to 1 000 Hz in line with ISO 2954. For machines running at or below 600 min^-1, the lower limit of the flat response range shall not be greater than 2 Hz.

Clause 5 also requires relative shaft vibration equipment to comply with ISO 10817-1 and says multi-directional sensors shall not be used. That matters because the sensor must measure the vibration direction intended by the test setup, or the result may not be valid for acceptance.

Mount the machine correctly

Clause 6 separates free suspension from rigid mounting. Free suspension uses springs or another elastic support, while rigid mounting uses a massive foundation or a rigid test floor stand with no elastic mounts.

Clause 6 also controls natural frequencies of the test arrangement, horizontal and vertical fixing, and the special setup for vertical machines. For practical testing, this is the part that determines whether a measured vibration level is comparable from one test to another. Clause 6.4 adds that if the standstill vibration at the same position exceeds 25% of the running value, an active environment exists and the standard does not apply.

Set the test conditions and positions

Clause 7 covers key treatment, measurement positions, direct-on-line tests, variable-speed tests, and transducer mounting. For direct-on-line tests, the machine is tested at no-load at each rated frequency with the corresponding rated voltage.

For variable-speed machines, Clause 7 requires a speed sweep or slow coast down over the specified range so that peak vibration levels can be found. The transducer mounting must not disturb the machine, and the coupled mass of the transducer assembly must be less than 1/50 of the machine mass.

Apply the correct vibration limits

Clause 8 sets the bearing-housing vibration limits in Table 1 and uses two vibration grades. Grade A applies when no special vibration requirements are stated, and Grade B applies when special vibration requirements are needed.

Clause 8 also distinguishes displacement-based limits for speeds below 600 min^-1 and velocity-based limits above that speed. For AC machines with a dominant twice-line-frequency component, the clause allows a higher limit under the stated conditions, which is important for two-pole induction machines.

Treat relative shaft vibration separately

Clause 9 limits relative shaft vibration mainly for sleeve-bearing machines with speeds above 1 200 min^-1 and rated power above 1 000 kW. Table 2 gives limits for shaft displacement and combined run-out, and Clause 9 explains how to reduce the effect of electrical run-out on the measurement.

What terms does FprEN IEC 60034-14:2026 define?

• Vibration magnitude - The broadband RMS vibration displacement or velocity measured at the machine bearings.
• Free suspension - A mounting condition where the machine is supported by springs or another elastic support.
• Rigid mounting - A mounting condition where the machine is fixed to a massive foundation or rigid test floor stand.
• Active environment - A condition where standstill vibration at the same position exceeds 25% of the running value.
• Grade A - The default vibration grade for machines with no special vibration requirements.
• Grade B - The vibration grade for machines with special vibration requirements.
• Run-out - A shaft measurement effect defined in ISO 2041:2018 and included in the relative shaft vibration limits.
• Relative shaft vibration displacement (S_p-p) - The peak-to-peak shaft displacement used for sleeve-bearing machines.

Who uses FprEN IEC 60034-14:2026?

FprEN IEC 60034-14:2026 is used by manufacturers of rotating electrical machines, test laboratories, suppliers, customers, and purchasers. They use it to set up factory acceptance tests, choose mounting arrangements, select measurement equipment, and decide whether measured vibration levels meet the required grade.

Quality and engineering teams use it to record test conditions and compare machines on a consistent basis. It is also useful when a buyer and supplier need to agree on special mounting arrangements, variable-speed testing, or special vibration requirements.

What changed in FprEN IEC 60034-14:2026 from the previous edition?

FprEN IEC 60034-14:2026 replaces the fourth edition published in 2018 and is described as a technical revision. The foreword states these significant changes:

• new subclauses were added in 6.3.3 for vertical machines type tests and routine tests
• new subclauses were added in 7.3 for direct-on-line and variable-speed test conditions
• Table 1 now has lower Grade A limits in free suspension for 56 ≤ H ≤ 132
• Clause 9 now includes information on reducing the effect of run-out on shaft vibration measurements

Which standards are used with FprEN IEC 60034-14:2026?

• IEC 60034-1 - gives rating and performance rules, and its terms and definitions apply in Clause 3.
• IEC 60034-7 - classifies construction and mounting arrangements.
• ISO 2954 - sets requirements for instruments that measure vibration severity.
• ISO 10817-1 - covers relative and absolute sensing of radial shaft vibration.
• ISO 20816-1 - provides general machine vibration guidance and is the reference for in situ vibration evaluation.
• ISO 21940-32 - gives the shaft and fitment key convention used for keyed shafts.
• ISO 20816-3 - is named in the notes for machines measured on site.

What does the FprEN IEC 60034-14:2026 document contain?

The document contains the measurement methods, mounting rules, test conditions, and acceptance limits needed for vibration testing of rotating electrical machines. Tables 1 and 2 give the vibration limits by shaft height, speed range, mounting condition, and vibration grade.

Figures 1 to 7 support the test setup by showing suspension requirements, measurement positions, transducer placement, vertical machine mounting, and the limit diagram for twice-line-frequency vibration. The document is used for factory acceptance, routine testing where performed, and technical agreement between supplier and customer.

SLOVENSKI STANDARD
oSIST prEN IEC 60034-14:2026
01-april-2026
Električni rotacijski stroji - 14. del: Mehanske vibracije nekaterih strojev za višino
gredi 56 mm in več - Meritve, vrednotenje in mejne vrednosti stopenj jakosti
Rotating electrical machines - Part 14: Mechanical vibration of certain machines with
shaft heights 56 mm and higher - Measurement, evaluation and limits of vibration
severity
Drehende elektrische Maschinen - Teil 14: Mechanische Schwingungen von bestimmten
Maschinen mit einer Achshöhe von 56 mm und höher - Messung, Bewertung und
Grenzwerte der Schwingstärke
Machines électriques tournantes - Partie 14: Vibrations mécaniques de certaines
machines de hauteur d'axe supérieure ou égale à 56 mm - Mesurage, évaluation et
limites de l'intensité vibratoire
Ta slovenski standard je istoveten z: prEN IEC 60034-14:2026
ICS:
17.160 Vibracije, meritve udarcev in Vibrations, shock and
vibracij vibration measurements
29.160.01 Rotacijski stroji na splošno Rotating machinery in
general
oSIST prEN IEC 60034-14:2026 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN IEC 60034-14:2026
oSIST prEN IEC 60034-14:2026
2/2290/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60034-14 ED5
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2026-02-06 2026-05-01
SUPERSEDES DOCUMENTS:
2/2268/CD, 2/2288/CC
IEC TC 2 : ROTATING MACHINERY
SECRETARIAT: SECRETARY:
United Kingdom Mr Charles Whitlock
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):
TC 9
ASPECTS CONCERNED:
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
Attention IEC-CENELEC parallel voting
The attention of IEC National Committees, members of
CENELEC, is drawn to the fact that this Committee Draft
for Vote (CDV) is submitted for parallel voting.
The CENELEC members are invited to vote through the
CENELEC online voting system.
This document is still under study and subject to change. It should not be used for reference purposes.
Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of
which they are aware and to provide supporting documentation.
Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some
Countries” clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is the
final stage for submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Rotating electrical machines - Part 14: Mechanical vibration of certain machines with shaft
heights 56 mm and higher - Measurement, evaluation and limits of vibration severity

PROPOSED STABILITY DATE: 2028
NOTE FROM TC/SC OFFICERS:
electronic file, to make a copy and to print out the content for the sole purpose of preparing National Committee positions.
You may not copy or "mirror" the file or printed version of the document, or any part of it, for any other purpose without
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oSIST prEN IEC 60034-14:2026
IEC CDV 60034-14 © IEC 2026
1 Contents
2 FOREWORD . 3
3 1 Scope . 5
4 2 Normative references . 5
5 3 Terms and definitions . 5
6 4 Measurement quantities. 6
7 4.1 General . 6
8 4.2 Vibration magnitude . 6
9 4.3 Relative shaft vibration . 6
10 5 Measurement equipment . 6
11 6 Machine mounting . 7
12 6.1 General . 7
13 6.2 Free suspension . 7
14 6.3 Rigid mounting . 7
15 6.3.1 Foundation . 7
16 6.3.2 Horizontal machines . 8
17 6.3.3 Vertical machines . 8
18 6.4 Active environment determination . 9
19 7 Conditions of measurement . 9
20 7.1 Key . 9
21 7.2 Measurement positions and directions . 9
22 7.2.1 Measurement positions for vibration . 9
23 7.2.2 Measurement positions for relative shaft displacement . 9
24 7.3 Test conditions . 9
25 7.3.1 Direct-on-line . 9
26 7.3.2 Variable speed . 10
27 7.4 Vibration transducer . 10
28 8 Limits of bearing housing vibration . 10
29 8.1 Limits of vibration magnitude . 10
30 8.2 Limits of vibration velocity with twice-line frequency for AC machines . 11
31 8.3 Axial vibration . 11
32 9 Limits of relative shaft vibration . 12
33 Bibliography . 17
oSIST prEN IEC 60034-14:2026
IEC CDV 60034-14 © IEC 2026
36 INTERNATIONAL ELECTROTECHNICAL COMMISSION
37 ____________
39 ROTATING ELECTRICAL MACHINES –
41 Part 14: Mechanical vibration of certain machines
42 with shaft heights 56 mm and higher – Measurement,
43 evaluation and limits of vibration severity
45 FOREWORD
46 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
47 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
48 co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
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51 preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
52 may participate in this preparatory work. International, governmental and non-governmental organizations liaising
53 with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
54 Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
55 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
56 consensus of opinion on the relevant subjects since each technical committee has representation from all
57 interested IEC National Committees.
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68 6) All users should ensure that they have the latest edition of this publication.
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72 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
73 Publications.
74 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
75 indispensable for the correct application of this publication.
76 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
77 rights. IEC shall not be held responsible for identifying any or all such patent rights.
78 International Standard IEC 60034-14 has been prepared by IEC technical committee 2: Rotating
79 machinery.
80 This fifth edition cancels and replaces the fourth edition, published in 2018. It constitutes a
81 technical revision.
82 The significant technical changes with respect to the previous edition are:
83 a) Subclause 6.3.3 Vertical machines: added two new subclauses: Type and Routine tests
84 b) Subclause 7.3 Test conditions: added two new subclauses: Direct-on-line and Variable
85 speed
86 c) Table 1: decreased limits for Grade A in free suspension for 56 ≤ H ≤ 132
87 d) Clause 9 Limits of relative shaft vibration: added information how to mitigate effects of
88 run-out on shaft vibration measurements.
oSIST prEN IEC 60034-14:2026
IEC CDV 60034-14 © IEC 2026
90 The text of this International Standard is based on the following documents:
FDIS Report on voting
2//FDIS 2//RVD
92 Full information on the voting for the approval of this International Standard can be found in the
93 report on voting indicated in the above table.
94 This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
95 A list of all parts in the IEC 60034 series, published under the general title Rotating electrical
96 machines, can be found on the IEC website.
97 NOTE For A table of cross-references of all IEC TC 2 publications can be found in the IEC TC 2 dashboard on the
98 IEC website.
99 The committee has decided that the contents of this document will remain unchanged until the
100 stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
101 the specific document. At this date, the document will be
102 • reconfirmed,
103 • withdrawn,
104 • replaced by a revised edition, or
105 • amended.
oSIST prEN IEC 60034-14:2026
IEC CDV 60034-14 © IEC 2026
108 ROTATING ELECTRICAL MACHINES –
110 Part 14: Mechanical vibration of certain machines
111 with shaft heights 56 mm and higher – Measurement,
112 evaluation and limits of vibration severity
116 1 Scope
117 This part of IEC 60034 specifies the factory acceptance vibration test procedures and vibration
118 limits for certain electrical machines under specified conditions, when uncoupled from any load
119 or prime mover.
120 It is applicable to DC and three-phase AC machines, with shaft heights 56 mm and higher and
–1
121 a rated output up to 50 MW, at operational speeds from 120 min up to and including
–1
122 15 000 min .
123 This document is not applicable to machines mounted in situ (on site), three-phase commutator
124 motors, single-phase machines, three-phase machines operated on single-phase systems,
125 vertical waterpower generators, turbine generators greater than 20 MW and machines with
126 magnetic bearings or series-wound machines.
127 NOTE 1 For machines measured in situ, refer to applicable parts of ISO 20816-1 and ISO 20816-3.
128 NOTE 2 For output power above 50 MW reference shall be made to ISO 20816 standards.
129 NOTE 3 Vibration routine tests are not mandatory according to IEC 60034-1. If performed the method for testing is
130 included in this standard.
131 2 Normative references
132 The following documents are referred to in the text in such a way that some or all their content
133 constitutes requirements of this document. For dated references, only the edition cited applies.
134 For undated references, the latest edition of the referenced document (including any
135 amendments) applies.
136 IEC 60034-1, Rotating electrical machines – Part 1: Rating and performance
137 IEC 60034-7, Rotating electrical machines – Part 7: Classification of types of constructions and
138 mounting arrangements (IM Code)
139 ISO 2954, Mechanical vibration of rotating and reciprocating machinery – Requirements for
140 instruments for measuring vibration severity
141 ISO 10817-1, Rotating shaft vibration measuring systems – Part 1: Relative and absolute
142 sensing of radial vibration from rotating shafts
143 ISO 20816-1, Mechanical vibration – Measurement and evaluation of machine vibration –
144 Part 1: General guidelines
145 ISO 21940-32, Mechanical vibration – Rotor balancing – Part 32: Shaft and fitment key
146 convention
147 3 Terms and definitions
148 For the purposes of this document, the terms and definitions given in IEC 60034-1 apply.
oSIST prEN IEC 60034-14:2026
IEC CDV 60034-14 © IEC 2026
149 ISO and IEC maintain terminological databases for use in standardization at the following
150 addresses:
151 • IEC Electropedia: available at http://www.electropedia.org/
152 • ISO Online browsing platform: available at http://www.iso.org/obp
153 4 Measurement quantities
154 4.1 General
155 Measurement quantities are the vibration displacement and vibration velocity at the machine
156 bearings and the relative shaft vibration displacement within or near to the machine bearings.
157 4.2 Vibration magnitude
158 The criterion for the vibration magnitude at the machine bearings shall be the broadband RMS
159 value of the vibration displacement in micrometres or the vibration velocity in millimeters per
160 second in the frequency range specified in Clause 5. The maximum value, determined at the
161 prescribed measurement positions and prescribed measuring variable, according to this
162 standard, characterizes the vibration magnitude of the machine.
163 Induction motors (especially of two pole type) frequently show vibration beating at twice slip
164 frequency. In these cases, the decisive vibration magnitude shall be determined from the
165 relationship:
2 2
𝑥𝑥 +𝑥𝑥
max min
�
166 𝑥𝑥 =
RMS
167 where
168 x is the maximum RMS value of vibration displacement or vibration velocity.
max
169 x is the minimum RMS value of vibration displacement or vibration velocity.
min
170 The sample rate shall be chosen large enough to reliably capture the maximum and minimum
171 values of the vibration.
172 NOTE Large AC induction machines running at very low slip values at no load may require several minutes to more
173 than ten minutes for such measurements to be completed at each vibration measuring position.
174 4.3 Relative shaft vibration
175 The criterion adopted for the relative shaft vibration shall be the vibratory peak-to-peak
176 displacement (S ) in the direction of measurement from ISO 20816-1.
p-p
177 5 Measurement equipment
178 The measurement equipment shall be capable of measuring broadband RMS vibration with flat
179 response over a frequency range of 10 Hz to 1 000 Hz, in accordance with the requirements of
–1
180 ISO 2954. However, for machines with speeds approaching or below 600 min , the lower limit
181 of the flat response frequency range shall not be greater than 2 Hz.
182 Measurement equipment for relative shaft vibration measurements shall comply with the
183 requirements in ISO 10817-1.
184 Multi-directional vibration sensors shall not be used.
185 NOTE Multi-directional sensors do not provide proper vibration measurement in all directions when mounted in only
186 one location.
oSIST prEN IEC 60034-14:2026
IEC CDV 60034-14 © IEC 2026
187 6 Machine mounting
188 6.1 General
189 The vibration of an electrical machine is closely linked with the mounting of the machine. To
190 permit evaluation as far as balance and vibration of rotating electrical machines are
191 concerned, it is necessary to measure the vibration on the machine alone, under properly
192 determined test conditions, to enable reproducible tests to be carried out and to provide
193 comparable measurements.
194 6.2 Free suspension
195 This condition is achieved by suspending the machine on a spring or by mounting on an elastic
196 support (springs, rubber, etc.).
197 The hi ghes t natural oscillation frequency (f ) of the suspension system and machine, shall
no
198 be less than 1/3 of the frequency f corresponding to the speed of the machine under test, as
199 defined in 7.3. Based on the mass of the machine being tested, the necessary elasticity of the
–1 –1
200 suspension system as a function of rated speed from 600 min to 3 600 min can be
–1
201 determined from Figure 1. For speeds lower than 600 min measurements in free suspension
–1
202 are not practical. For speeds greater than 3 600 min , the static displacement Z should be not
–1
203 less than the value for 3 600 min .
204 The curve in Figure 1 presents the minimum elastic displacement to attain the necessary vertical
205 rigid body natural oscillation, which is usually the highest rigid body natura
...