SIST EN 61007:2002
(Main)Transformers and inductors for use in electronic and telecommunication equipment - Measuring methods and test procedures
Transformers and inductors for use in electronic and telecommunication equipment - Measuring methods and test procedures
Describes measuring methods and test procedures for inductors and transformers for use in electronic and telecommunication equipment that may be involved in any specifications for such components, in particular those forming part of the IEC Quality Assessment System for Electronic Components (IECQ).
Transformatoren und Drosseln für die Anwendung in elektronischen und nachrichtentechnischen Einrichtungen - Meßmethoden und Prüfverfahren
Transformateurs et inductances utilisés dans les équipements électroniques et de télécommunications - Méthodes de mesure et procédures d'essais
Décrit les méthodes de mesures et les procédures d'essais pour les inductances et les transformateurs utilisés dans les équipements électroniques et de télécommunications qui peuvent être employées dans les spécifications de tous ces composants, en particulier ceux qui entrent dans le cadre de l'assurance de la qualité des composants électroniques du système CEI (IECQ).
Transformers and inductors for use in electronic and telecommunication equipment- Measuring methods and test procedure (IEC 61007:1994, modified)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 61007:2002
01-september-2002
Transformers and inductors for use in electronic and telecommunication
equipment- Measuring methods and test procedure (IEC 61007:1994, modified)
Transformers and inductors for use in electronic and telecommunication equipment -
Measuring methods and test procedures
Transformatoren und Drosseln für die Anwendung in elektronischen und
nachrichtentechnischen Einrichtungen - Meßmethoden und Prüfverfahren
Transformateurs et inductances utilisés dans les équipements électroniques et de
télécommunications - Méthodes de mesure et procédures d'essais
Ta slovenski standard je istoveten z: EN 61007:1997
ICS:
29.180 Transformatorji. Dušilke Transformers. Reactors
SIST EN 61007:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 61007:2002
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SIST EN 61007:2002
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SIST EN 61007:2002
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SIST EN 61007:2002
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SIST EN 61007:2002
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SIST EN 61007:2002
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SIST EN 61007:2002
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SIST EN 61007:2002
NORME
CEI
INTERNATIONALE
IEC
61007
INTERNATIONAL
Deuxième édition
STAN DARD
Second edition
1994-10
Transformateurs et inductances utilisés
dans les équipements électroniques
et de télécommunications —
Méthodes de mesure et procédures d'essais
Transformers and inductors for use
in electronic and telecommunication
equipment —
Measuring methods and test procedures
© IEC 1994 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
utilisée sous quelque forme que ce soit et par aucun any form or by any means, electronic or mechanical,
procédé, électronique ou mécanique, y compris la photo- including photocopying and microfilm, without permission in
copie et les microfilms, sans l'accord écrit de l'éditeur. writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http: //www.iec.ch
CODE PRIX XA
Commission Electrotechnique Internationale
PRICE CODE
International Electrotechnical Commission
IEC
MenviyHapoiateR 3nenrporexHNVecKafl HoMHCCNH
Pour prix, voir catalogue en vigueur
• • For price, see current catalogue
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SIST EN 61007:2002
—3—
1007 ©IEC:1994
CONTENTS
Page
FOREWORD 7
Clause
1 Scope 9
2 Normative references 9
13
3 Terminology
4 Test procedures 21
21
4.1 Test and measurement conditions
21
4.1.1 Measurement uncertainty
Alternative test methods 21
4.1.2
21
4.2 Visual inspection
23
4.2.1 Safety screen position
23
4.2.2 Quality of solder joints
27
4.3 Dimensioning and gauging procedure
27
4.4 Electrical test procedures
4.4.1 Winding resistance 27
29
4.4.2 Insulation tests
37
4.4.3 Losses
39
4.4.4 Inductance
43
4.4.5 Unbalance
55
4.4.6 Capacitance
61
4.4.7 Transformation ratios
67
4.4.8 Resonant frequency
71
4.4.9 Signal transfer characteristics
79
4.4.10 Frequency response
79
4.4.11 Pulse characteristics
81
4.4.12 Voltage-time product rating
85
4.4.13 Total harmonic distortion
87
4.4.14 Voltage regulation
4.4.15 Temperature rise 89
4.4.16 Surface temperature 91
4.4.17 Phase test (polarity) 93
97
4.4.18 Screens
4.4.19 Noise 99
103
4.4.20 Corona test
103
4.4.21 Magnetic fields
4.4.22 Inrush current 109
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SIST EN 61007:2002
— 5 —
1007 ©IEC:1994
Page
Clause
4.5 109
Environmental test procedures
109
4.5.1 General
111
4.5.2 Soldering
111
Robustness of terminations and integral mounting devices 4.5.3
111
4.5.4 Shock
111
4.5.5 Bump
111
Vibration (sinusoidal) 4.5.6
111
4.5.7 Acceleration, steady state
111
Rapid change of temperature (thermal shock in air)
4.5.8
111
Sealing 4.5.9
111
4.5.10 Climatic sequence
4.5.11 Damp heat, steady state 113
113
4.5.12 Dry heat
113
Mould growth 4.5.13
113
4.5.14 Salt mist, cyclic (sodium chloride solution)
115 4.5.15 Sulphur dioxide test for contacts and connections
115
4.5.16 Fire hazard
115
4.5.17 Immersion in cleaning solvents
115 4.6 Endurance test procedures
115
4.6.1 Short-term endurance (load run)
117
4.6.2 Long-term endurance (life test)
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SIST EN 61007:2002
1007 ©IEC:1994 — 7 —
INTERNATIONAL ELECTROTECHNICAL COMMISSION
TRANSFORMERS AND INDUCTORS FOR USE
IN ELECTRONIC AND TELECOMMUNICATION EQUIPMENT -
MEASURING METHODS AND TEST PROCEDURES
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization
comprising all national electrotechnical committees (IEC National Committees). The object of the IEC is to
promote international cooperation on all questions concerning standardization in the electrical and
electronic fields. To this end and in addition to other activities, the IEC publishes International Standards.
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. The 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 the IEC on technical matters, prepared by technical committees on
which all the National Committees having a special interest therein are represented, express, as nearly as
possible, an international consensus of opinion on the subjects dealt with.
3) They have the form of recommendations for international use published in the form of standards, technical
reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
International Standard IEC 1007 has been prepared by IEC technical committee 51:
Magnetic components and ferrite materials.
This second edition cancels and replaces the first edition published in 1990, and amend-
ments 1 and 2 (published in 1993), and constitutes a technical revision.
The text of this standard is based on the first edition of IEC 1007, amendments 1 and 2
and the following documents:
DIS Report on voting
51 (C0)309
51(CO)312
Full information on the voting for the approval of this standard can be found in the report
on voting indicated in the above table.
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SIST EN 61007:2002
1007 ©IEC:1994 - 9 -
TRANSFORMERS AND INDUCTORS FOR USE
IN ELECTRONIC AND TELECOMMUNICATION EQUIPMENT -
MEASURING METHODS AND TEST PROCEDURES
1 Scope
This standard describes measuring methods and test procedures for inductors and trans-
formers for use in electronic and telecommunication equipment that may be involved in
any specifications for such components, in particular those forming part of the IEC Quality
Assessment System for Electronic Components (IECQ scheme).
2 Normative references
The following normative documents contain provisions which, through reference in this
text, constitute provisions of IEC 1007. At the time of publication, the editions indicated
were valid. All normative documents are subject to revision, and parties to agreements
based on IEC 1007 are encouraged to investigate the possibility of applying the most
recent editions of the normative documents indicated below. Members of IEC and ISO
maintain registers of currently valid International Standards.
IEC 27: Letter symbols to be used in electrical technology
IEC 44-4: 1980,
Instrument transformers - Part 4: Measurement of partial discharges
IEC 50, International Electrotechnical Vocabulary (IEV)
IEC 68-1: 1988, Environmental testing - Part 1: General and guidance
Amendment 1 (1992)
IEC 68-2: Environmental testing - Part 2: Tests
IEC 68-2-1: 1990, Environmental testing - Part 2: Tests - Tests A: Cold
Amendment 1 (1993)
IEC 68-2-2: 1974, Environmental testing - Part 2: Tests - Tests B: Dry heat
Amendment 1 (1993)
IEC 68-2-3: 1969,
Environmental testing - Part 2: Tests - Test Ca: Damp heat, steady
state
IEC 68-2-6: 1982,
Environmental testing - Part 2: Tests - Test Fc and guidance: Vibration
(sinusoidal)
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SIST EN 61007:2002
1007 ©IEC:1994 - 11 -
IEC 68-2-7: 1983, Environmental testing - Part 2: Tests - Test
Ga and guidance: Accel-
eration, steady state
Amendment 1 (1986)
IEC 68-2-10: 1988, Environmental testing - Pa rt 2: Tests - Test J and guidance: Mould
growth
IEC 68-2-13: 1983, Environmental testing - Part 2: Tests - Test M: Low air pressure
IEC 68-2-14: 1984, Environmental testing - Part 2: Tests - Test N: Change of temperature
Amendment 1 (1986)
IEC 68-2-17: 1978, Environmental testing - Part 2: Tests - Test Q: Sealing
Amendment 4 (1991)
IEC 68-2-20: 1979, Environmental testing - Part 2: Tests - Test T: Soldering
Amendment 2 (1989)
IEC 68-2-21: 1983, Environmental testing - Part 2: Tests - Test U: Robustness of termin-
ations and integral mounting devices
Amendment 2 (1991), Amendment 3 (1992)
IEC 68-2-27: 1987, Environmental testing - Part 2: Tests - Test Ea and guidance: Shock
IEC 68-2-29: 1987, Environmental testing - Part 2: Tests - Test Eb and guidance: Bump
IEC 68-2-30: 1980, Environmental testing - Part 2: Tests - Test Db and guidance: Damp
heat, cyclic (12 + 12-hour cycle)
Amendment 1 (1985)
IEC 68-2-42: 1982, Environmental testing - Pa rt 2: Tests - Test Kc: Sulphur dioxide test
for contacts and connections
IEC 68-2-45: 1980, Environmental testing - Part 2: Tests - Test XA and guidance: Immer-
sion in cleaning solvents
IEC 68-2-52: 1984, Environmental testing - Part 2: Tests - Test Kb: Salt: mist, cyclic
(sodium chloride solution)
IEC 68-2-58: 1989, Environmental testing - Part 2: Tests - Test Td: Solderability,
resistance to dissolution of metallization and to soldering heat of Surface Mounting
Devices (SMD)
IEC 270: 1981, Partial discharge measurements
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SIST EN 61007:2002
1007 ©IEC:1994 - 13 -
IEC 367-1: 1982,
Cores for inductors and transformers for telecommunications - Part 1:
Measuring methods
Amendment 1 (1984), Amendment 2 (1992)
IEC 551: 1987,
Determination of transformer and reactor sound levels
IEC 617, Graphical symbols for diagrams
IEC 651: 1979, Sound level meters
Amendment 1 (1993)
IEC 695-2: Fire hazard testing - Part 2: Test methods
IEC 695-2-2: 1991,
Fire hazard testing - Part 2: Test methods - Section 2: Needle-flame
test
IEC 695-2-4/0: 1991, Fire hazard testing - Part 2: Test methods - Section 4/Sheet 0:
Diffusion type and pre-mixed type flame test methods
IEC 695-2-4/1: 1991,
Fire hazard testing - Part 2: Test methods - Section 4/Sheet 1:
1 kW nominal pre-mixed test flame and guidance
ISO 3: 1973,
Preferred numbers - Series of preferred numbers
ISO 497: 1973,
Guide to the choice of series of preferred numbers and of series contain-
ing more rounded values of preferred numbers
ISO 1000: 1992,
SI units and recommendations for the use of their multiples and of certain
other units
3 Terminology
For the purpose of this standard the following definitions apply in addition to those of
IEC 50:
3.1 component:
A transformer or an inductor.
3.2 peak working voltage: The maximum instantaneous voltage for which the winding
insulation is rated under working circuit conditions.
3.3 pulse waveform parameters (see figure 1)
a) peak pulse amplitude, Urn : The maximum value of an extrapolated smooth curve
through the top of the pulse, excluding any initial "spike" or "overshoot", the duration of
which is less than 10 % of the pulse duration.
b) pulse duration, td : The time interval between the first and last instants at which the
pulse amplitude equals 50 % of the peak pulse amplitude.
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SIST EN 61007:2002
Leading edge Pulse top Trailing edge
Pulse crest
Overshooti
% tJmf
100
Droop
90
80
50
Pulse duration
Rèturn backswing
td
Cycle time
10
0
t
Back
–10 —
swing
Rise Fall
time
time
Recovery time
tf
590/90
tr
NOTE - For clarity in illustrating droop, the 80% and 10% points have been used in constructing the line
which determines the border between the pulse top and the trailing edge.
Figure 1 - Pulse waveform parameters
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SIST EN 61007:2002
1007 CD IEC:1994 - 17
c) pulse rise time, t
r: The interval between the first instant at which the pulse
amplitude reaches 10 % of the peak pulse amplitude and the first instant at which the
pulse amplitude reaches 90 % of the peak pulse amplitude, excluding any unwanted or
irrelevant po
rtion of the waveform.
d) pulse fall time, tf:
The interval between the last instant at which the pulse
amplitude reaches 90 % of the peak pulse amplitude and the next instant at which the
pulse amplitude reaches 10 % of the peak pulse amplitude, excluding any unwanted or
irrelevant po rtion of the waveform.
NOTE — Where the value of the droop approaches 10 % of the peak pulse amplitude, the upper point
defining fall time may be replaced by the last instant at which the pulse amplitude reaches 80 % of the
peak pulse amplitude.
e) droop:
The difference between the peak pulse amplitude and the amplitude of the
extrapolated smooth curve through the top of the pulse, excluding any initial "spike" or
"overshoot", at its intersection with the straight line through the points defining the
pulse fall time, expressed as a percentage of the peak pulse amplitude.
f) pulse crest:
The maximum amplitude of the pulse.
g) overshoot:
The amount by which the pulse crest exceeds the peak pulse
amplitude. Overshoot is expressed as a percentage of the peak pulse amplitude.
h) backswing: The maximum amplitude of the reverse pulse, i.e. the po
rtion of the
pulse after the zero-crossing, expressed as a percentage of the peak pulse amplitude.
i) return
backswing: The maximum amplitude of the swing that follows the back-
swing, expressed as a percentage of the peak pulse amplitude.
j)
recovery time: The time interval between the end of the pulse fall time and the time
at which the pulse amplitude last reaches +10 % of the peak pulse amplitude. Excep-
tionally, a figure less than 10 % may be used, in which case the interval is termed "the
X % recovery time".
k) pulse
repetition frequency (prf): The average number of pulses in unit time when
this is independent of the period over which it is measured.
3.4 Q factor (quality factor): The ratio of the energy stored to the energy dissipated
during one cycle at a particular frequency in a specified winding. It is expressed in terms
of either the series or the parallel components of reactance and loss resistance.
3.5 harmonic distortion: The square root of the sum of the square of all harmonic
voltages up to and including the seventh harmonic (excluding the fundamental) expressed
as a percentage or as a ratio in decibels of the fundamental.
3.6 maximum winding temperature: The mean temperature rise of any winding of the
component under full load, when thermal stability has been achieved, added to the
specified maximum ambient temperature.
3.7 voltage-time product rating: The voltage pulse amplitude multiplied by the time
elapsed from the start of the pulse within which the non-linearity of the magnetizing
current does not exceed a specified value.
3.8 background (acoustic) noise: The noise measured at a measuring point with the
exclusion of that produced by the component under test.
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SIST EN 61007:2002
1007©IEC:1994 - 19 --
3.9 compass safe distance:
The distance from the pivot of the test magnetometer or
compass to the nearest point on the surface of the component under test, at which the
magnetic deviation is limited to a stated value.
3.10 duty ratio; duty factor:
The ratio of pulse duration td to the cycle time.
3.11
current transformer parameters
a) burden:
That property of the circuit connected to the secondary winding of a
current transformer which determines the real and reactive power at the secondary
terminals. It is expressed as total impedance with effective resistive and reactive
components or as the total volt-amperes and power factor at the specified values of
current and frequency.
b) current transformation ratio, k:
The ratio of the r.m.s. value of the primary current
to the r.m.s. value of the secondary current under specified conditions.
c) phase angle:
The angular displacement between the vectors representing the
primary and secondary currents of the transformer. The phase angle is positive when
the secondary current leads the primary current.
d) ratio error:
The difference between the measured current transformation ratio k
and its nominal value
kn, divided by the measured value, and expressed as a percent-
age.
kn - k
ratio error = x 100 (per cent)
k
3.12 electrostatic screen:
A conducting screen inserted between windings that, when it
is connected to earth, considerably reduces the transference of unwanted signals from
one winding to the other via interwinding capacitance.
3.13 safety screen: A conducting screen inserted between windings that, when it is
connected to earth, effectively prevents fault currents flowing between those windings, in
the event of an insulation failure.
3.14
polarity (applicable to single-phase windings): A property of a single-phase
winding such that a terminal on one winding has the same polarity as a terminal on
another winding if, when the other ends of the windings are connected to form a common
terminal and the transformer/inductor is energized with a sinusoidal voltage, the induced
voltage appearing between each of the two terminals and the common terminal is rising
positively through zero at the same instant of time.
3.15 uniformly-
insulated winding: A winding in which the insulation to earth is, at
all points, designed to withstand an electric strength test of a value appropriate to the
insulation of the high-voltage end.
3.16 graded-insulated winding:
A winding in which insulation to earth is graded from
the amount at the high-voltage end to a smaller amount at the low-voltage end.
NOTE – Such a winding should withstand an electric strength test of a value appropriate to the insulation of
the low-voltage end.
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SIST EN 61007:2002
1007 ©
IEC:1994 — 21 —
4 Test procedures
4.1 Test and measurement conditions
Unless otherwise specified all tests shall be carried out under standard atmospheric
conditions for testing as specified in IEC 68-1. Where there is a requirement for compo-
nents to attain temperature stability this shall be in accordance with 4.8 of IEC 68-1.
Unless otherwise stated in the detail specification, all voltages and currents shall be
sinusoidal; values shall be taken as r.m.s. and polyphase supplies shall be assumed to be
balanced.
The "information to be stated" that is required to complete the descriptions of test methods
in this clause shall be specified in the relevant detail specification for the component. The
detail specification shall also specify the test fixture to be used in association with a
component, where this is intended for use at frequencies high enough for the length of test
leads to become significant.
4.1.1 Measurement uncertainty
The limits quoted in detail specifications shall be absolute. The tolerance values applying
to the actual measurement system shall be taken into account when the measurements
are assessed against specification limits. Where tolerances in respect of set conditions or
instrument error have been prescribed these shall be regarded as additional minimum
requirements.
4.1.2 Alternative test methods
The test and measurement methods given in the relevant specification shall not be
regarded as the only methods to be used. Special test equipment and automatic test sets
are available, which may also be used. However, the tester shall satisfy the customer or
relevant authority (see Note 1) that any alternative methods which he may use will give
results equivalent (see Note 2) to those obtained by standard methods. In the case of
dispute, for referee and reference purposes the specified methods only shall be used.
Alternative test methods shall not be shown in detail specifications.
NOTES
1 Such as a National Supervising Inspectorate within the IECQ scheme.
2 By "equivalent" it is meant that the value of the characteristic established by such other method and
deemed acceptable in accordance with the limits ascribed to such other method will fall within the specified
limits when measured by the specified method.
4.2 Visual inspection
Visual inspection shall be performed under normal factory lighting without visual aids. The
condition, workmanship, marking and finish shall be
satisfactory.
NOTE — If special lighting and/or visual aids are necessary for the acceptance of particular components
(e.g. very small components), these may be specified as additional tests in the relevant detail specification.
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SIST EN 61007:2002
1007 © IEC:1994 - 23 -
4.2.1 Safety screen position
NOTE — Sometimes the term "isolating screen" is used as an alternative to "safety screen".
Purpose:
To determine the position of a safety screen in relation to adjacent windings.
Procedure:
The fitted and positioned safety screen shall be inspected before being
obscured by subsequent windings. The safety screen shall:
a)
totally cover the winding around which it is wrapped such that the "finish" end over-
laps the "start" end by no less than the amount specified in the detail specification;
b)
be adequately insulated so as not to comprise a short-circuited winding;
c) have edges extending sufficiently along the winding being screened to prevent
direct contact between windings.
NOTE — Screens fitted to toroidal transformers may consist of a number of turns of conductive strip
provided that each turn overlaps the adjacent turn by not less than 5 % of the strip width.
Information to be stated:
- minimum overlap.
4.2.2 Quality of solder joints
NOTE — A good solder joint is one that has excellent electrical contact between the parts joined and good
mechanical strength. Examples of good solder joints are shown in figure 2. Figure 3 illustrates defective
joints.
Purpose: To determine the quality of all solder joints.
Procedure:
All solder joints shall be inspected to ensure that the following requirements
are complied with:
Requirements: Soldered joints shall:
a) exhibit good tinning as evidenced by the free flowing of solder with wetting of the
termination;
b) be smooth with no spikes;
c) be bright and shiny;
d) be without rough patches;
e)
shall have a concave surface and the outline of the wire shall be visible under the
surface of the solder;
f)
not have been moved during soldering (such joints exhibit an "orange peel" effect,
as shown in figure 3a);
g)
not be "dry" (that is, shall not exhibit a distinct line where the solder fillet joins the
wire or have a high contact angle between the solder and the wire (see figure 3b));
h)
be wired at terminals in such a way as to leave no residual stress (see figure 3c);
i) not exhibit "wicking" (that is, the joining wire shall not be overheated, leading to the
movement of solder into multi-stranded wires (see figure 3d)).
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SIST EN 61007:2002
25 -
1007 © IEC:1994 -
J
591/90
Figure 2 - Examples of good solder joints
ro
_z__-,
X
(
593/90
Figure 3a - Moved joint Figure 3b - Dry joints
Insulation
I
I
I
I
I Solder
in the multistrand wire
i
A I kr makes it brittle
595/90
Figure 3c - Mechanically stressed joint Figure 3d - Wicking
Figure 3 - Examples of defective joints
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SIST EN 61007:2002
1007 ©IEC:1994 - 27 -
4.3
Dimensioning and gauging procedure
The dimensions shall be verified as being in accordance with the relevant specification.
4.4
Electrical test procedures
4.4.1
Winding resistance
4.4.1.1 D.C. winding resistance
Purpose: To determine the d.c. resistance of a winding or windings between specified
terminations.
Procedure: The resistance shall be measured by a suitable method.
Where required by the detail specification, the ambient temperature A (in °C) shall be
measured and the result of the resistance measurement R
m (in I) corrected to the
corresponding value at 20 °C, R20 (in by means of the following formula:
k + 20
Rm
R20 k + 0
where k
is a constant related to the thermal coefficient of resistivity. For the purposes of
this standard, the value for copper shall be taken as 234,5 and for aluminium as 228,1.
NOTE – For safety reasons, consideration should be given to short-circuiting windings capable of produc-
ing high voltages at current interruption.
Information to be stated:
a) terminations between which the measurement is to be made;
b) whether the result of measurement should be corrected to 20 °C, and if so, the
value of k to be used for materials other than copper or aluminium.
NOTES
1 The selected method should be determined by the ease of operating the test and the accuracy re-
quired. The accuracy of the equipment should be at least ten times better than the accuracy required of the
test.
2 The measuring current should not be so large as to cause self-heating or to have a significant magnet-
izing effect on the component.
4.4.1.2 Continuity
Purpose: To verify the continuity of a specified winding.
Procedure:
Continuity shall be established using a suitable d.c. or a.c. voltage or current
source, and a suitable detector.
Information to be stated:
- winding to be tested.
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SIST EN 61007:2002
1007 © IEC:1994 — 29 —
NOTES
1 The current should not be so large as to have a significant magnetizing effect on the component.
2 Care should be taken in testing a winding with a high inductance value as a high voltage may be
generated.
3 Where there are parallel paths, as with multiple windings or in polyphase components, a d.c.
resistance check may be necessary to ensure that the path under examination is not being influenced by
shunt paths.
4.4.2 Insulation tests
4.4.2.1 Electric strength test
Purpose:
To ensure that the insulation of uniformly-insulated windings and the low-
voltage end insulation of graded-insulated windings are adequate.
NOTES
1 This test is not suitable for the high-voltage end insulation of windings having graded insulation or
designed to have one point earthed*. The high-voltage end insulation of such windings can be tested only
by the application of an appropriate induced voltage test (see item b) of special conditions of test of
4.4.2.2).
2 In ce rt
ain cases it may be appropriate to demonstrate the adequacy of the low-voltage end insulation
of graded-insulated windings during the induced voltage test (see item b) of special conditions of test of
4.4.2.2).
Procedure: A test voltage whose value is selected from the table below, unless otherwise
specified, shall be applied between specified pairs of isolated elements of the component.
All windings shall be short-circuited. Windings and screens on one side of the insulation
system shall be connected to frame, core and earth while windings and screens on the
other side shall be connected together.
Electric strength test voltages
A.C. test voltage, 45 - 65 Hz
Peak working voltage D.C. test voltage
(r.m.s.)
V v V
pk r.m.s.
<25
50 71
>25 to 50 100
141
>50 to
100 300
424
>100 to 175 500 707
>175 to 700 2,8 x peak working voltage
4 x peak working voltage
>700
1,4 x peak working voltage
2 x peak working voltage
+ 1 000 + 1 400
The test voltage shall be increased at a convenient rate but not exceeding 2 kV per sec-
ond, from zero to the specified value, maintained at this value for the specified time (un-
less breakdown occurs), then decreased to zero at the same rate.
In the USA, "ground" is used in place of "earth" and "grounded" in place of "earthed".
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SIST EN 61007:2002
1007 ©IEC:1994 – 31 –
For fluid-filled components, except for those designed for operation in one plane only and
so marked, approximately half the test sample shall be tested with terminals uppermost
and half with the terminals underneath.
If a specified environmental conditioning is required for this test the component shall be
held for a minimum of 6 h unless otherwise specified in the specified conditions. (See
IEC 68 for information on environmental testing.)
There shall be no evidence of heating, breakdown or deterioration. Ionization shall not be
regarded as a criterion of breakdown. The leakage current shall not exceed the specified
value.
Information to be stated:
a) terminations between which the test is to be made;
b)
test voltage (for a winding having graded-insulation, values shall be given for both
ends of the winding);
c) frequency of a.c. test voltage (if diffe
...
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