SIST EN 60034-28:2007

Rotating electrical machines - Part 28: Test methods for determining quantities of equivalent circuit diagrams for three-phase low-voltage cage induction motors (IEC 60034-28:2007)

This part of IEC 60034 applies to three-phase low-voltage cage induction motors of frame numbers 56 to 400 as specified in IEC 60072-1. This standard establishes procedures to obtain values for elements of single phase equivalent circuit diagrams from tests and defines standard elements of these diagrams.

Drehende elektrische Maschinen - Teil 28: Prüfverfahren zur Bestimmung der Größen in Ersatzschaltbildern dreiphasiger Niederspannungs-Kurzschlussläufer-Induktionsmotoren (IEC 60034-28:2007)

Machines électriques tournantes - Partie 28: Méthodes d'essai pour la détermination des grandeurs des schémas d'équivalence des circuits pour moteurs à induction à cage basse tension triphasés (CEI 60034-28:2007)

S'applique aux moteurs à induction à cage basse tension triphasés de désignations de carcasses entre 56 et 400, spécifiés dans la CEI 60072-1. Définit des éléments normalisés de schémas de circuits équivalents monophasés et établit à partir d'essais des procédures pour obtenir des valeurs pour ces éléments.

Električni rotacijski stroji - 28. del: Preskušalne metode za ugotavljanje veličin nadomestnih shem trifaznih nizkonapetostnih motorjev z indukcijsko kletko (IEC 60034-28:2007)

General Information

• Status: Withdrawn
• Publication Date: 27-Sep-2007
• Withdrawal Date: 09-Dec-2015
• ICS: 29.160.30 - Motors
• Technical Committee: ERS - Rotating machinery
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 10-Dec-2015
• Due Date: 02-Jan-2016
• Completion Date: 10-Dec-2015
• Ref Project: EN 60034-28:2007 - Rotating electrical machines - Part 28: Test methods for determining quantities of equivalent circuit diagrams for three-phase low-voltage cage induction motors

Relations

• Revised: SIST EN 60034-28:2013 - Rotating electrical machines - Part 28: Test methods for determining quantities of equivalent circuit diagrams for three-phase low-voltage cage induction motors (IEC 60034-28:2012)
• Effective Date: 06-May-2014
• Replaced By: SIST EN 60034-28:2013 - Rotating electrical machines - Part 28: Test methods for determining quantities of equivalent circuit diagrams for three-phase low-voltage cage induction motors (IEC 60034-28:2012)
• Effective Date: 29-Jan-2023
• Replaced By: SIST EN 60034-28:2013 - Rotating electrical machines - Part 28: Test methods for determining quantities of equivalent circuit diagrams for three-phase low-voltage cage induction motors (IEC 60034-28:2012)
• Effective Date: 01-Sep-2013

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 60034-28:2007
01-november-2007
(OHNWULþQLURWDFLMVNLVWURMLGHO3UHVNXãDOQHPHWRGH]DXJRWDYOMDQMHYHOLþLQ
QDGRPHVWQLKVKHPWULID]QLKQL]NRQDSHWRVWQLKPRWRUMHY]LQGXNFLMVNRNOHWNR,(&

Rotating electrical machines - Part 28: Test methods for determining quantities of
equivalent circuit diagrams for three-phase low-voltage cage induction motors (IEC
60034-28:2007)
Drehende elektrische Maschinen - Teil 28: Prüfverfahren zur Bestimmung der Größen in
Ersatzschaltbildern dreiphasiger Niederspannungs-Kurzschlussläufer-Induktionsmotoren
(IEC 60034-28:2007)
Machines électriques tournantes - Partie 28: Méthodes d'essai pour la détermination des
grandeurs des schémas d'équivalence des circuits pour moteurs à induction à cage
basse tension triphasés (CEI 60034-28:2007)
Ta slovenski standard je istoveten z: EN 60034-28:2007
ICS:
29.160.30 Motorji Motors
SIST EN 60034-28:2007 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 60034-28:2007

---------------------- Page: 2 ----------------------

SIST EN 60034-28:2007


EUROPEAN STANDARD
EN 60034-28

NORME EUROPÉENNE
May 2007
EUROPÄISCHE NORM

ICS 29.160


English version


Rotating electrical machines -
Part 28: Test methods for determining quantities
of equivalent circuit diagrams
for three-phase low-voltage cage induction motors
(IEC 60034-28:2007)


Machines électriques tournantes -  Drehende elektrische Maschinen -
Partie 28: Méthodes d'essai Teil 28: Prüfverfahren
pour la détermination des grandeurs zur Bestimmung der Größen
des schémas d'équivalence des circuits in Ersatzschaltbildern dreiphasiger
pour moteurs à induction Niederspannungs-Kurzschlussläufer-
à cage basse tension triphasés Induktionsmotoren
(CEI 60034-28:2007) (IEC 60034-28:2007)




This European Standard was approved by CENELEC on 2007-05-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60034-28:2007 E

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SIST EN 60034-28:2007
EN 60034-28:2007 - 2 -
Foreword
The text of document 2/1415/FDIS, future edition 1 of IEC 60034-28, prepared by IEC TC 2, Rotating
machinery, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as
EN 60034-28 on 2007-05-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2008-02-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2010-05-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60034-28:2007 was approved by CENELEC as a European
Standard without any modification.
__________

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SIST EN 60034-28:2007
- 3 - EN 60034-28:2007
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication Year Title EN/HD Year

1) 2)
IEC 60034-1 - Rotating electrical machines - EN 60034-1 2004
Part 1: Rating and performance


IEC 60044 Series Instrument transformers EN 60044 Series


1) 2)
IEC 60051-1 - Direct acting indicating analogue electrical EN 60051-1 1998
measuring instruments and their
accessories -
Part 1: Definitions and general requirements
common to all parts


1)
IEC 60072-1 - Dimensions and output series for rotating - -
electrical machines -
Part 1: Frame numbers 56 to 400 and flange
numbers 55 to 1 080




1)
Undated reference.
2)
Valid edition at date of issue.

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SIST EN 60034-28:2007

---------------------- Page: 6 ----------------------

SIST EN 60034-28:2007
NORME CEI
INTERNATIONALE
IEC



60034-28
INTERNATIONAL


Première édition
STANDARD

First edition

2007-03


Machines électriques tournantes –
Partie 28:
Méthodes d’essai pour la détermination des
grandeurs des schémas d’équivalence des
circuits pour moteurs à induction à cage
basse tension triphasés

Rotating electrical machines –
Part 28:
Test methods for determining quantities of
equivalent circuit diagrams for three-phase
low-voltage cage induction motors
© IEC 2007 Droits de reproduction réservés ⎯ Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
CODE PRIX
U
PRICE CODE
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

---------------------- Page: 7 ----------------------

SIST EN 60034-28:2007
60034-28 © IEC:2007 – 3 –
CONTENTS
FOREWORD.5
INTRODUCTION.9

1 Scope.11
2 Normative references .11
3 Terms, definitions and symbols .11
3.1 Symbols .11
3.2 Equivalent Y-connection.17
4 Test requirements .17
4.1 Frequency and voltage .17
4.2 Instrumentation .17
5 Approximations and uncertainties .19
6 Test procedures .19
6.1 General .19
6.2 Stator d.c. line-to-line resistance measurement .21
6.3 Load-test.21
6.4 No-load test.21
6.5 Reverse rotation and locked rotor tests .23
7 Determination of motor quantities .23
7.1 General .23
7.2 Resistance of stator winding R .27
s
7.3 Equivalent resistance of iron losses R .27
fe
7.4 Total stator inductance L = L + L .29
ts m s
7.5 Total leakage inductance L .33
σ
7.6 Magnetizing inductance L and voltage U .37
m m
7.7 Stator and rotor leakage inductances L and L ’ .37
s r
7.8 Inductances for calculations at constant flux (rated load).37
7.9 Resistance of rotor cage R ’ referred to stator winding.39
r

Annex A (informative) Form for calculation of resistance of iron losses R .43
fe
Annex B (informative) Form for calculation of total stator inductance L .45
ts
Annex C (informative) Form for calculation of total leakage inductance L .47
σ
Annex D (informative) Form for calculation of magnetizing inductance L .49
m
Annex E (informative) Sample calculation .51

Figure 1 – Type-T equivalent circuit diagram .25
Figure 2 – Type-T equivalent circuit diagram (iron losses disregarded) .25
Figure 3 – Type-L equivalent circuit diagram (iron losses disregarded) .25
Figure 4 – Typical characteristic of inductance L over current I .31

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SIST EN 60034-28:2007
60034-28 © IEC:2007 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________

ROTATING ELECTRICAL MACHINES –

Part 28: Test methods for determining quantities of equivalent circuit
diagrams for three-phase low-voltage cage induction motors


FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60034-28 has been prepared by IEC technical committee 2:
Rotating machinery.
The text of this standard is based on the following documents:
FDIS Report on voting
2/1415/FDIS 2/1423/RVD

Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

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SIST EN 60034-28:2007
60034-28 © IEC:2007 – 7 –
A list of all parts of IEC 60034 series, under the general title Rotating electrical machines, can
be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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SIST EN 60034-28:2007
60034-28 © IEC:2007 – 9 –
INTRODUCTION
Equivalent circuits are widely used in the control of adjustable speed drives with induction
motors supplied by frequency inverters. The motor parameters are required for the realisation
of flux oriented control or other model-based control algorithms. Their knowledge is required
by suppliers and system engineers, especially when motors and frequency inverters from
different suppliers are combined.
This part of IEC 60034 provides a standardized test procedure to determine the electric motor
parameters. At the same time this standard offers an improved understanding of the
equivalent circuit method. The procedures can be carried out in laboratories equipped for
standard electric machinery tests.
NOTE The standard’s main purpose is for assistance in modelling frequency controlled motors. Due to the
simplifications, the results cannot be used to determine motor performance or efficiency accurately.
A related technical specification is IEC 60034-25: “Guide for the design and performance of
cage induction motors specifically designed for converter supply" where required motor
parameters are listed, but their definition and methods of their determination are not included.

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SIST EN 60034-28:2007
60034-28 © IEC:2007 – 11 –
ROTATING ELECTRICAL MACHINES –

Part 28: Test methods for determining quantities of equivalent circuit
diagrams for three-phase low-voltage cage induction motors



1 Scope
This part of IEC 60034 applies to three-phase low-voltage cage induction motors of frame
numbers 56 to 400 as specified in IEC 60072-1.
This standard establishes procedures to obtain values for elements of single phase equivalent
circuit diagrams from tests and defines standard elements of these diagrams.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60034-1, Rotating electrical machines – Part 1: Rating and performance
IEC 60044 (all parts), Instrument transformers
IEC 60051-1, Direct acting indicating analogue electrical measuring instruments and their
accessories – Part 1: Definitions and general requirements common to all parts
IEC 60072-1, Dimensions and output series for rotating electrical machines – Part 1: Frame
numbers 56 to 400 and flange numbers 55 to 1080
3 Terms, definitions and symbols
For the purposes of this document, the terms and definitions given in IEC 60034-1 apply. The
following symbols apply.
3.1 Symbols
cos ϕ is the power factor
cos ϕ is the rated power factor
N
–1
f is the stator supply frequency, s
1
–1
f is the frequency of the rotor current (slip frequency), s
r
–1
f is the rated frequency, s
N
h is the height of the rotor-conductor bar, m

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SIST EN 60034-28:2007
60034-28 © IEC:2007 – 13 –
H is the motor frame size according to IEC 60072-1 (shaft height), mm
I is the stator line-current, A
I is a current component used for calculations, A
a
I is a current component used for calculations, A
b
I is the stator phase-current, A
s
I ’ is the rotor current, A
r
I is a current component used for calculations, A
ra
is a current component used for calculations, A
I
rb
I is the magnetizing current, A
m
I is the rated stator current, A
N
k is the skin-effect factor for inductances
i
k is the reciprocal of the temperature coefficient of resistance at 0 °C of the rotor
r
conductor material, see Note 1
k is the reciprocal of the temperature coefficient of resistance at 0 °C of the stator
s
conductor material, see Note 1
k is the ratio of stator to rotor leakage inductance
σ
L is the magnetizing inductance, H
m
L is the stator leakage inductance, H
s
L’ is the rotor leakage inductance, H
r
L is the total leakage inductance (= L + L’ ), H
σ s r
is the total leakage inductance disregarding the skin effect, H
L
σa
L is the total stator inductance (= L + L ), H
ts m s
L’ is the total rotor inductance (= L + L’ ), H
tr m r
–1
n is the operating speed, s
–1
n is the rated speed, s
N
–1
n is the rated synchronous speed, s
syn
p is the number of pole pairs
P is the electrical input power, W
1

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SIST EN 60034-28:2007
60034-28 © IEC:2007 – 15 –
P is the constant losses, W
k
P is the windage and friction losses, W
fw
P is the iron losses, W
fe
R is the line resistance, Ω
R is the equivalent circuit resistance of iron losses, Ω
fe
R , is the stator line-to-line resistance at initial winding temperature, Ω
ll m
R is the stator phase-resistance corrected to a temperature of 25 °C, Ω
s,25
is the rotor cage resistance, Ω
R’
r
R’ is the rotor resistance corrected to an ambient temperature of 25 °C, Ω
r,25
R’ is the rotor resistance at initial winding temperature, Ω
r,m
s is the slip, in per unit value of synchronous speed
s is the rated slip
N
U is the stator terminal voltage, V
U is the stator phase voltage, V
s
U is the voltage drop over the magnetizing inductance, V
m
U is a voltage component used for calculations, V
ma
U is a voltage component used for calculations, V
mb
U is the rated terminal voltage, V
N
X is the magnetizing reactance (= 2πf ⋅L ), Ω
m 1 m
X is the stator leakage reactance (= 2πf ⋅L ), Ω
s 1 s
X’ is the rotor leakage reactance (= 2πf ⋅L’ ), Ω
r 1 r
X is the total leakage reactance (= 2πf ⋅L ), Ω
σ 1 σ
X is the total leakage reactance disregarding the skin-effect, Ω
σa
X is the total stator reactance (= 2πf ⋅L ), Ω
ts 1 ts
X’ is the total rotor reactance (= 2πf ⋅L’ ), Ω
tr 1 tr
Z is the motor impedance, Ω

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SIST EN 60034-28:2007
60034-28 © IEC:2007 – 17 –
γ is the conductivity of rotor conductor, S/m, see Note 2
r
ξ is the current displacement factor of rotor conductor
θ is the temperature of the cold winding at initial resistance measurement, °C
0
θ is the temperature of the winding at the end of the thermal load test, °C
L
θ is the temperature of the winding at the end of the thermal no-load test, °C
NL
NOTE 1 For copper use k = 235, for aluminium use k = 225, unless otherwise specified.
6 6
NOTE 2 For copper rotor-bars use γ = 56⋅10 S/m, for aluminium rotor-bars use γ = 33⋅10 S/m unless otherwise
r r
specified.
NOTE 3 Symbols with underscore (like U) represent complex values. Symbols without underscore represent
2 2
absolute values (U = |U| = √ [Re{U} + Im{U} ] ).The calculations according to this standard are limited to absolute
values.
NOTE 4 All rotor values are referred to the stator winding; relevant symbols marked with a prime (‘).
3.2 Equivalent Y-connection
The quantities in the equivalent circuit diagram are presented as per-phase-values in
equivalent Y-connection. The mathematical model of the machine shall be regarded as Y-
connected, also in the case of delta connection of the actual motor.
NOTE The equivalent Y-connection is also the basis to express the equivalent circuit quantities as per-unit
values.
4 Test requirements
4.1 Frequency and voltage
The frequency shall be within ± 0,3 % of the specified test frequency during measurements.
The form and symmetry of the supply voltage shall conform to the requirements of 8.3.1 of
IEC 60034-1.
4.2 Instrumentation
4.2.1 Measuring instruments for electrical quantities, speed and frequency
The measuring instruments shall have an accuracy class of 0,5 or better in accordance with
IEC 60051-1. However, accuracy class for the measurement of resistance shall be 0,1.
Since instrument accuracy is generally expressed as a percentage of full scale, the range of
the instrument chosen shall be as low as practical.
4.2.2 Instrument transformers
Instrument transformers shall have an accuracy class of 0,2 according to IEC 60044.
4.2.3 Temperature measurement
The instrumentation used to measure temperatures shall have an accuracy of ± 1 °C.

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SIST EN 60034-28:2007
60034-28 © IEC:2007 – 19 –
5 Approximations and uncertainties
The procedures described to obtain the values of the equivalent circuit diagram include
approximations. Furthermore, the equivalent circuit diagram is an approximation in itself.
The inductances are determined depending on current in order to take saturation effects of
the iron core into account. However, iron losses are disregarded in the determination formulae
of all inductances.
Eddy current effects on inductances and resistances are disregarded because the application
of the obtained equivalent circuit parameters is not intended to the start-up process of the
motor (i.e. application to slips between 0 … ≈ ±0,3 only).
The assumption of short-circuited rotor resistance during the determination of the total
leakage inductance L (see 7.5) will typically result in an error less than 5 % on the obtained
σ
1
value . The effect on the magnetizing inductance L (see 7.6) is negligible.
m
Furthermore the relatively large rotor frequencies (at s = 2 or s = 1) during the tests for total
leakage inductance require skin-effect compensation. Unless rotor design data are available,
the calculation must be based on an estimated rotor conductor-bar height (see 7.5.2).
The distribution of the total leakage inductance L into stator and rotor leakage inductances
σ
(L and L’ , see 7.7) is based on rough assumptions and cannot be performed accurately by
s r
the methods described in this standard.
The difference of rotor and winding temperature is neglected during the determination of rotor
resistance R’ (7.9).
r
While core losses in the stator are included, those in the rotor are disregarded. This is a valid
assumption for slips between 0 and breakdown slip. However, the start-up situation cannot be
represented correctly.
Furthermore, this simplification gives rise to errors in the determination of leakage
inductances from the reverse rotation test (see 6.5.2) since the rotor frequency becomes
twice the rated frequency in this case.
To adjust the equivalent iron loss resistance to other than rated frequencies, the distribution
of hysteresis losses versus eddy current losses needs to be known. This standard presents a
suitable approximation (see 7.3.3).
6 Test procedures
6.1 General
The subtests that make up this test procedure shall be performed in the sequence listed. It is
not essential that the tests are carried out immediately one after another. However, if the
subtests are performed individually, then the specified thermal conditions shall be re-
established prior to obtaining the test data.
———————
1
 For very small motors (rated power less than 1 kW) the error can increase due to the relatively large values of
rotor resistance.

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SIST EN 60034-28:2007
60034-28 © IEC:2007 – 21 –
The arithmetic average of the three line currents and voltages shall be used. The stator line-
to-line resistance is the value across any two terminals for which a reference value has been
measured at known temperature.
It is recommended that whenever measurements of voltage, current, speed or power for a
certain load point are required the actual test data is an average value of several samples
taken in short time intervals to compensate for load fluctuations.
6.2 Stator d.c. line-to-line resistance measurement
The temperature of the winding when the resistance is measured shall not differ from the
coolant by more than 2 K.
Measure and record R . The resistance shall be taken as the average value from
ll,m
measurements of all three phases. Measure and record the winding temperature θ according
0
to 8.6.2 of IEC 60034-1.
6.3 Load-test
Before starting to record data for this test, the temperature of the stator winding shall be
within 5 °C of the temperature obtained from a rated load thermal test (see IEC 60034-1).
Apply rated voltage of rated frequency to the terminals. Increase the load until the line current
is equal to rated current I .
N
Measure and record U,I , P and n. Measure and record the winding temperature θ according
1 l
to 8.6.2 of IEC 60034-1. The first reading of resistance shall be taken within the time
specified in Table 5 of IEC 60034-1.
6.4 No-load test
The no-load test shall be done right after the load test to ensure stabilization of the losses
and a defined temperature.
Decouple the motor from any load or other machine. By adjusting the supply voltage of rated
frequency, measure and record U, I and P for at least 10 values of current.
1
NOTE This test should be done with a slip as close to zero as possible. Therefore, seals or other devices
causing additional friction should be removed if suitable.
The highest voltage shall be selected according to the capabilities of the laboratory. However,
it shall be not less than 110 % of the rated voltage of the motor and not exceed the value that
will result in a no-load current greater than 150 % of rated current. The lowest voltage shall be
approximately 20 % of rated voltage. However, it shall not fall below the value where further
reduction increases the current.
The test shall be carried out as quickly as possible with the readings taken in descending
order of voltage.

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SIST EN 60034-28:2007
60034-28 © IEC:2007 – 23 –
After the test, measure and record the winding temperature θ according to 8.6.2 of
NL
IEC 60034-1. The first reading of resistance shall be taken within
...