SIST EN 61180:2017

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Tehnike visokonapetostnega preskušanja nizkonapetostne opreme - Definicije, preskusne in postopkovne zahteve, preskusna opremaHigh-voltage test techniques for low voltage equipment - Definitions, test and procedure requirements, test equipment19.080SUHVNXãDQMHElectrical and electronic testingICS:Ta slovenski standard je istoveten z:EN 61180:2016SIST EN 61180:2017en01-februar-2017SIST EN 61180:2017SLOVENSKI
STANDARDSIST EN 61180-2:1998SIST EN 61180-1:19981DGRPHãþD

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 61180
October 2016 ICS 19.080
Supersedes
EN 61180-1:1994, EN 61180-2:1994
English Version
High-voltage test techniques for low-voltage equipment - Definitions, test and procedure requirements, test equipment (IEC 61180:2016)
Techniques des essais à haute tension pour matériel à basse tension - Définitions, exigences et modalités relatives aux essais, matériel d'essai (IEC 61180:2016)
Hochspannungs-Prüftechnik für Niederspannungsgeräte - Begriffe, Prüfung und Prüfbedingungen, Prüfgeräte (IEC 61180:2016) This European Standard was approved by CENELEC on 2016-07-29. 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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17,
B-1000 Brussels © 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 61180:2016 E SIST EN 61180:2017

This document supersedes EN 61180-1:1994 and EN 61180-2:1994. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 61180:2016 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 61000-4-5:2014 NOTE Harmonized as EN 61000-4-5:2014 (not modified). IEC 61010-1 NOTE Harmonized as EN 61010-1. IEC 61010-2-030:2010 NOTE Harmonized as EN 61010-2-030:2010 (not modified). SIST EN 61180:2017

Normative references to international publications with their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here: www.cenelec.eu.
Publication Year Title EN/HD Year IEC 60060-1 2010
High-voltage test techniques -
Part 1: General definitions and test requirements EN 60060-1 2010
IEC 60060-2 2010
High-voltage test techniques -
Part 2: Measuring systems EN 60060-2 2011
IEC 60068-1 2013
Environmental testing -
Part 1: General and guidance EN 60068-1 2014
IEC 60335 series
Household and similar electrical appliances - Safety
EN 60335 series
IEC 60664-1 2007
Insulation coordination for equipment within low-voltage systems -
Part 1: Principles, requirements and tests EN 60664-1 2007
IEC 61083-1 2001
Instruments and software used for measurement in high-voltage impulse tests -
Part 1: Requirements for instruments EN 61083-1 2001
IEC 61083-2 2013
Instruments and software used for measurement in high-voltage and high-current tests -
Part 2: Requirements for software for tests with impulse voltages and currents EN 61083-2 2013
ISO/IEC Guide 98-3 2008
Uncertainty of measurement -
Part 3: Guide to the expression of uncertainty in measurement (GUM:1995) - -
IEC 61180 Edition 1.0 2016-06 INTERNATIONAL STANDARD NORME INTERNATIONALE High-voltage test techniques for low-voltage equipment – Definitions, test and procedure requirements, test equipment
Techniques des essais à haute tension pour matériel à basse tension – Définitions, exigences et modalités relatives aux essais, matériel d'essai
INTERNATIONAL ELECTROTECHNICAL COMMISSION COMMISSION ELECTROTECHNIQUE INTERNATIONALE
ICS 19.080
ISBN 978-2-8322-3366-5
– 2 – IEC 61180:2016 © IEC 2016 CONTENTS FOREWORD . 5 1 Scope . 7 2 Normative references. 7 3 Terms and definitions . 8 3.1 General terms . 8 3.2 Definitions related to disruptive discharge and test voltages . 8 3.3 Characteristics related to the test equipment . 9 3.4 Characteristics related to direct voltage tests . 9 3.5 Characteristics related to alternating voltage tests . 10 3.6 Characteristics related to impulse tests (see Figure 1) . 11 3.7 Definitions relating to tolerance and uncertainty . 12 4 General requirements . 13 4.1 General . 13 4.2 Atmospheric conditions for test procedures and verification of test equipment . 14 4.3 Procedures for qualification and use of measuring systems . 14 4.3.1 General principles . 14 4.3.2 Schedule of performance tests . 15 4.3.3 Requirements for the record of performance . 15 4.3.4 Uncertainty . 15 4.4 Tests and test requirements for an approved measuring system and its components . 16 4.4.1 Calibration – Determination of the scale factor . 16 4.4.2 Influence of load . 18 4.4.3 Dynamic behaviour . 18 4.4.4 Short-term stability . 19 4.4.5 Long-term stability . 19 4.4.6 Ambient temperature effect . 20 4.4.7 Uncertainty calculation of the scale factor . 20 4.4.8 Uncertainty calculation of time parameter measurement (impulse voltages only) . 22 5 Tests with direct voltage . 25 5.1 General . 25 5.2 Test voltage . 25 5.2.1 Requirements for the test voltage . 25 5.2.2 Generation of the test voltage . 25 5.2.3 Measurement of the test voltage . 25 5.3 Test procedures . 26 5.3.1 Withstand voltage tests . 26 6 Tests with alternating voltage . 27 6.1 Test voltage . 27 6.1.1 Requirements for the test voltage . 27 6.1.2 Generation of the test voltage . 27 6.1.3 Measurement of the test voltage . 28 6.2 Test procedures . 30 6.2.1 Withstand voltage tests . 30 7 Tests with impulse voltage . 30 SIST EN 61180:2017

IEC 61180:2016 © IEC 2016 – 3 – 7.1 Test voltage . 30 7.1.1 General . 30 7.1.2 Requirements for the test voltage . 31 7.1.3 Generation of the test voltage . 31 7.1.4 Measurement of the test voltage and determination of impulse shape . 32 7.2 Test procedures . 32 7.2.1 Verification of impulse voltage waveshape . 32 7.2.2 Impulse voltage tests . 32 7.3 Measurement of the test voltage . 32 7.3.1 Requirements for an approved measuring system . 32 7.3.2 Uncertainty contributions . 33 7.3.3 Dynamic behaviour . 33 7.3.4 Requirements for measuring instrument . 33 8 Reference measurement systems . 33 8.1 Requirements for reference measuring systems . 33 8.1.1 Direct voltage. 33 8.1.2 Alternating voltage . 33 8.1.3 Impulse voltages . 33 8.2 Calibration of a reference measuring system . 33 8.2.1 General . 33 8.2.2 Reference method: comparative measurement . 34 8.3 Interval between successive calibrations of reference measuring systems . 34 8.4 Use of reference measuring systems . 34 Annex A (informative)
Uncertainty of measurement . 35 A.1 General . 35 A.2 Terms and definitions in addition to 3.7 . 35 A.3 Model function . 36 A.4 Type A evaluation of standard uncertainty . 36 A.5 Type B evaluation of standard uncertainty . 37 A.6 Combined standard uncertainty . 38 A.7 Expanded uncertainty . 39 A.8 Effective degrees of freedom . 40 A.9 Uncertainty budget . 40 A.10 Statement of the measurement result . 41 Annex B (informative)
Example for the calculation of measuring
uncertainties in high-voltage measurements . 43 Annex C (informative)
Atmospheric correction . 47 C.1 Standard reference atmosphere . 47 C.2 Atmospheric correction factor . 47 C.2.1 General . 47 C.2.2 Humidity correction factor k2 . 47 C.2.3 Air density correction factor k1 . 48 Bibliography . 49
Figure 1 – Full impulse voltage time parameters . 11 Figure 2 – Calibration by comparison over the full voltage range . 17 Figure 3 – Uncertainty contributions of the calibration
(example with a minimum of 5 voltage levels) . 18 SIST EN 61180:2017

– 4 – IEC 61180:2016 © IEC 2016 Figure 4 – Shaded area for acceptable normalised amplitude-frequency
responses of measuring systems intended for single fundamental frequencies fnom
(to be tested in the range (1….7) fnom) . 29 Figure 5 – Shaded area for acceptable normalised amplitude-frequency
responses of measuring systems intended for a range of fundamental frequencies fnom1 to fnom2 (to be tested in the range fnom1 to 7 fnom2) . 29 Figure 6 – 1,2/50 µs standard impulse voltage . 31 Figure A.1 – Normal probability distribution p(x) . 42 Figure A.2 – Rectangular probability distribution p(x) . 42
Table 1 – Tests required for an approved direct voltage measuring system . 26 Table 2 – Minimum currents of the test circuit . 27 Table 3 – Tests required for an approved alternating voltage measuring system . 30 Table 4 – Tests required for an approved impulse voltage measuring system . 33 Table A.1 – Coverage factor k for effective degrees of freedom eff (p = 95,45 %) . 40 Table A.2 – Schematic of an uncertainty budget . 41 Table B.1 – Result of the comparison measurement up to 500 V at a single voltage level . 44 Table B.2 – Summary of results for h = 5 voltage levels (VXmax = 500 V) . 45 Table B.3 – Uncertainty budget of the assigned scale factor FX . 46
IEC 61180:2016 © IEC 2016 – 5 – INTERNATIONAL ELECTROTECHNICAL COMMISSION ____________
HIGH-VOLTAGE TEST TECHNIQUES FOR LOW-VOLTAGE EQUIPMENT –
Definitions, test and procedure requirements, test equipment
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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 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 61180 has been prepared by IEC technical committee 42: High-voltage and high-current test techniques. This 1st edition of IEC 61180 cancels and replaces the 1st edition of IEC 61180-1, issued in 1992, and the 1st edition of IEC 61180-2, issued in 1994. The text of this standard is based on the following documents: FDIS Report on voting 42/341/FDIS 42/342/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. SIST EN 61180:2017

– 6 – IEC 61180:2016 © IEC 2016 The committee has decided that the contents of this publication will remain unchanged until the stability date indicated on the IEC website 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.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users should therefore print this document using a colour printer.
IEC 61180:2016 © IEC 2016 – 7 – HIGH-VOLTAGE TEST TECHNIQUES FOR LOW-VOLTAGE EQUIPMENT –
Definitions, test and procedure requirements, test equipment
1 Scope This International Standard is applicable to: – dielectric tests with direct voltage; – dielectric tests with alternating voltage; – dielectric tests with impulse voltage; – test equipment used for dielectric tests on low-voltage equipment. This standard is applicable only to tests on equipment having a rated voltage of not more than 1 kV a.c. or 1,5 kV d.c. This standard is applicable to type and routine tests for objects which are subjected to high voltage tests as specified by the technical committee. The test equipment comprises a voltage generator and a measuring system. This standard covers test equipment in which the measuring system is protected against external interference and coupling by appropriate screening, for example a continuous conducting shield. Therefore, simple comparison tests are sufficient to ensure valid results. This standard is not intended to be used for electromagnetic compatibility tests on electric or electronic equipment
NOTE Tests with the combination of impulse voltages and currents are covered by IEC 61000-4-5. This standard provides the relevant technical committees as far as possible with: – defined terms of both general and specific applicability; – general requirements regarding test objects and test procedures; – methods for generation and measurement of test voltages; – test procedures; – methods for the evaluation of test results and to indicate criteria for acceptance; – requirements concerning approved measuring devices and checking methods; – measurement uncertainty.
Alternative test procedures may be required and these should be specified by the relevant technical committees. Care should be taken if the test object has voltage limiting devices, as they may influence the results of the test. The relevant technical committees should provide guidance for testing objects equipped with voltage limiting devices. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For SIST EN 61180:2017

– 8 – IEC 61180:2016 © IEC 2016 undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60060-1:2010, High-voltage test techniques – Part 1: General definitions and test requirements IEC 60060-2:2010, High-voltage test techniques – Part 2: Measuring systems IEC 60068-1:2013, Environmental testing – Part 1: General and guidance IEC 60335(all parts): Household and similar electrical appliances – Safety IEC 60664-1:2007, Insulation co-ordination for equipment within low-voltage systems – Part 1: Principles, requirements and tests IEC 61083-1:2001, Instruments and software used for measurement in high-voltage impulse test – Part 1: Requirements for instruments IEC 61083-2:2013, Instruments and software used for measurement in high-voltage and high-current tests – Part 2: Requirements for software for tests with impulse voltages and currents ISO/IEC Guide 98-3:2008, Uncertainty of measurement – Part 3: Guide to the expression of uncertainty in measurements (GUM) 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 General terms 3.1.1
clearance distance between two conductive parts along a string stretched across the shortest path between these conductive parts
[SOURCE: IEC 60050-441:1984, 441-17-31] 3.1.2
creepage distance shortest distance along the surface of a solid insulating material between two conductive parts
[SOURCE: IEC 60050-151: 2001, 151-15-50] 3.2 Definitions related to disruptive discharge and test voltages 3.2.1
disruptive discharge failure of insulation under electric stress, in which the discharge completely bridges the insulation under test, reducing the voltage between electrodes to practically zero 3.2.2
withstand voltage specified voltage value which characterizes the insulation of the object with regard to a withstand test SIST EN 61180:2017

IEC 61180:2016 © IEC 2016 – 9 – Note 1 to entry: Unless otherwise specified, withstand voltages are referred to standard reference atmospheric conditions (see 4.2). 3.3 Characteristics related to the test equipment 3.3.1
calibration set of operations that establishes, by reference to standards, the relationship which exists, under specified conditions, between an indication and a result of a measurement Note 1 to entry: The determination of the scale factor is included in the calibration. [SOURCE: IEC 60050-311:2001, 311-01-09, modified: note modified] 3.3.2
type test conformity test made on one or more items representative of the production
Note 1 to entry: For a measuring system, this is a test performed on a component or on a complete measuring system of the same design to characterize it under operating conditions. [SOURCE: IEC 60050-151: 2001, 151-16-16, modified:note added]
3.3.3
routine test conformity test made on each individual item during or after manufacture Note 1 to entry: This is a test performed on each component or on each complete measuring system to characterize it under operating conditions. [SOURCE: IEC 60050-151: 2001, 151-16-17, modified:note added] 3.3.4
performance test test performed on a complete measuring system to characterize it under operating conditions 3.3.5
test equipment complete set of devices needed to generate and measure the test voltage or current applied to a test object 3.3.6
reference measuring system measuring system with its calibration traceable to relevant national and/or international standards, and having sufficient accuracy and stability for use in the approval of other systems by making simultaneous comparative measurements with specific types of waveform and ranges of voltage 3.3.7
assigned scale factor scale factor of a measuring system determined at the most recent performance test Note 1 to entry: A measuring system may have more than one assigned scale factor; for example, it may have several ranges, each with a different scale factor. 3.4 Characteristics related to direct voltage tests 3.4.1
value of the test voltage arithmetic mean value SIST EN 61180:2017

– 10 – IEC 61180:2016 © IEC 2016 3.4.2
ripple periodic deviation from the arithmetic mean value of the test voltage 3.4.3
ripple amplitude half the difference between the maximum and minimum values Note 1 to entry: In cases where the ripple shape is nearly sinusoidal, true r.m.s. values multiplied by √=2 are acceptable for determination of the ripple amplitude. 3.4.4
ripple factor ratio of the ripple amplitude to the value of test voltage 3.5 Characteristics related to alternating voltage tests 3.5.1
peak value average of the magnitudes of the positive and negative maximum values 3.5.2
r.m.s. value square root of the mean value of the square of the voltage values during a complete cycle 3.5.3
true r.m.s. value value obtained from ∫=TttiTI02)(1drms where 0 is the time instant (t = 0) of an a.c. periodic wave, convenient for the beginning of integration; T
is the time taken over an integral number of cycles; i(t) is the instantaneous value of the current. Note 1 to entry: The true r.m.s. value can in general be calculated from a digitized record of any periodic waveform, provided a sufficient number of samples have been taken. Note 2 to entry: In cases with varying frequency, no strict formula for true r.m.s. value can be given. 3.5.4
total harmonic distortion THD
the ratio of the rms value of the harmonic content of an alternating quantity to the rms value of the fundamental component of the quantity [SOURCE: IEC 60050-551: 1998, 551-17-06] SIST EN 61180:2017

IEC 61180:2016 © IEC 2016 – 11 – 3.6 Characteristics related to impulse tests (see Figure 1)
Figure 1 – Full impulse voltage time parameters Note 1 to entry: Oscillations are negligible. 3.6.1
impulse voltage intentionally applied aperiodic transient voltage which usually rises rapidly to a peak value and then falls more slowly to zero 3.6.2
peak value maximum value 3.6.3
value of the test voltage for an impulse without overshoot or oscillations, its peak value Note 1 to entry: The determination of the peak value, in the case of oscillations or overshoot on standard impulses, is considered in IEC 60060-1. 3.6.4
front time
T1 virtual parameter defined as 1/0,6 times the interval T between the instants when the impulse is 30 % and 90 % of the peak value on the test voltage curve (points A and B, Figure 1) 3.6.5
virtual origin
O1 instant preceding point A, of the test voltage curve (see Figure 1) by a time 0,3 T1 Note 1 to entry: For records having linear time scales, this is the intersection with the time axis of a straight line drawn through the reference points A and B on the front. IEC U 1,0 0,9 0,5 0,3 0 T′
T T2 t B A O1 O T1 T1 = T/ 0,6 T′ = 0,3 T1 = 0,5 T SIST EN 61180:2017

– 12 – IEC 61180:2016 © IEC 2016 3.6.6
time to half-value
T2 virtual parameter defined as the time interval between the virtual origin O1 and the instant when the voltage has decreased to half the peak value 3.6.7
recorded curve graphical or digital representation of the test data of an impulse voltage 3.7 Definitions relating to tolerance and uncertainty 3.7.1
tolerance permitted difference between the measured value and the specified value 3.7.2
uncertainty of measurement parameter, associated with the result of a measurement, that characterizes the dispersion of the values that could be reasonably attributed to the measurand
Note 1 to entry: Uncertainty is positive and given without sign. [SOURCE: IEC 60050-311:2001, 311-01-02] 3.7.3
error
measured quantity value minus a reference quantity value [SOURCE: ISO/IEC Guide 98-3:2008, GUM 2.3.2] 3.7.4
standard uncertainty
u uncertainty of the result of a measurement expressed as a standard deviation Note 1 to entry: The standard uncertainty associated with an estimate of a measurand has the same dimension as the measurand. Note 2 to entry: In some cases, the relative standard uncertainty of a measurement may be appropriate. The relative standard uncertainty of measurement is the standard uncertainty divided by the measurand, and is therefore dimensionless. [SOURCE: ISO/IEC Guide 98-3:2008, GUM 2.3.1] 3.7.5
combined standard uncertainty
uc standard uncertainty of the result of a measurement when that result is obtained from the values of a number of other quantities, equal to the positive square root of a sum of terms, the terms being the variances or covariances of these other quantities weighted according to how the measurement result varies with changes in these quantities [SOURCE: ISO/IEC Guide 98-3:2008, GUM 2.3.4] SIST EN 61180:2017

IEC 61180:2016 © IEC 2016 – 13 – 3.7.6
expanded uncertainty
U quantity defining an interval about the result of a measurement that may be expected to encompass a large fraction of the distribution of values that could reasonably be attributed to the measurand Note 1 to entry: Expanded uncertainty is the closest match to the term “overall uncertainty”. Note 2 to entry: The true, but unknown test-voltage value may lie outside the limits given by the uncertainty because the coverage probability is < 100 % (see 3.7.7). [SOURCE: ISO/IEC Guide 98-3:2008, GUM 2.3.5, modified:notes added] 3.7.7
coverage factor k numerical factor used as multiplier of the combined standard uncertainty in order to obtain an expanded uncertainty Note 1 to entry: For 95 % coverage probability and normal (Gaussian) probability distribution the coverage factor is approximately k = 2. [SOURCE: ISO/IEC Guide 98-3:2008, GUM 2.3.6, modified:note added] 3.7.8
type A evaluation method of evaluation of an uncertainty by statistical analysis of a series of observations 3.7.9
type B evaluation method of evaluation of an uncertainty by means other than statistical analysis of a series of observations 3.7.10
national metrology institute institute designated by national decision to develop and maintain national measurement standards for one or more quantities 4 General requirements 4.1 General Unless otherwise specified by the relevant technical committee, the test object should be clean and dry, stabilized to ambient environmental conditions and the voltage application shall be as specified in the relevant clauses of this standard. The test procedures applicable to particular types of test objects, should be specified by the relevant technical committee, having regard to such factors as: • the required accuracy of test results; • the random nature of the observed phenomenon and any polarity dependence of the measured characteristics; • the possibility of progressive deterioration with repeated voltage applications. This includes for example, the polarity to be used, the preferred order if both polarities are to be used, the number of applications and the interval between applications, and any conditioning and preconditioning. SIST EN 61180:2017

– 14 – IEC 61180:2016 © IEC 2016 The connections between the test equipment and the object subjected to the high voltage test shall be direct and as short as possible. Loops of the connections should be avoided to minimize oscillations on the front of the impulse. The leads should be as close to each other as possible in order to minimize the area between the leads.
These requirements shall also apply for the qualification of the measuring system, e.g. the test equipment to be calibrated and the reference measuring system. The manufacturer of the test equipment shall give information on the characteristics of the test equipment, so that the generated voltage is still within the allowed tolerances when testing the object subjected to the high voltage test. 4.2 Atmospheric conditions for test procedures and verification of test equipment The atmospheric conditions for test procedures and the verification of test equipment shall be those stated for testing in IEC 60068-1: Temperature 15 °C to 35 °C Air pressure 86 kPa to 106 kPa Relative humidity 25 % to 75 % Absolute humidity
≤ 22 g/m3 The actual atmospheric conditions during the test shall be recorded. For the purpose of testing, where the atmospheric conditions are within the ranges specified in this standard, corrections to the test voltage due to variations of the temperature, humidity and air pressure do not need to be applied. When the atmospheric conditions during the test are not within the ranges specified in this standard, the method in Annex C shall be used, by agreement, for test voltage correction. 4.3 Procedures for qualification and use of measuring systems 4.3.1 General principles Every approved measuring system shall undergo initial tests, followed by periodic performance tests throughout its service life, as specified in 4.3.2. The initial tests consist of type tests and routine tests. The performance tests shall prove that the measuring systems can measure the intended test voltages within the uncertainties given in this standard, and that the measurements are traceable to national and/or international standards of measurement. The system is approved only for the arrangements and operating conditions included in its record of performance, as specified in 4.3.3. A major requirement for measuring systems is stability within the specified range of operating conditions so that the scale factor remains constant over long periods. The assigned scale factor is determined in the performance test by calibration. Any calibration shall be traceable to national and/or international standards. The user shall ensure that any calibration is performed by competent personnel using reference measuring systems and suitable procedures. Alternatively, any user may choose to have the performance tests made by a national metrology institute or by a calibration laboratory accredited for the quantity to be calibrated.
IEC 61180:2016 © IEC 2016 – 15 – Calibrations performed by a national metrology institute, or by a laboratory accredited for the quantities calibrated and reported under the accreditation, are considered traceable to national and/or international standards. In all cases, the user shall include the test data in the record of performance. 4.3.2 Schedule of performance tests To maintain the quality of a measuring system, the assigned scale factor(s) shall be determined by periodic performance tests. The interval between performance tests shall be not longer than 1 year unless otherwise stated by the manufacturer and based on experience demonstrating long-term stability. Performance tests shall be made following major repairs to the measuring system and whenever a circuit arrangement that is beyond the limits given in the record of performance is to be used. 4.3.3 Requirements for the record of performance The results of all tests, including the conditions under which the results were obtained, shall be kept in the record of performance (stored in paper format or electronically if permitted by quality systems and local laws) established and maintained by the user. The record of performance shall uniquely identify the components of the measuring system and shall be structured so that performance of the measuring system can be traced over time. The record of performance shall comprise at least the following information:
• General description of the measuring system. • Results of type and routine tests on the measuring system. • Results of subsequent performance tests on the measuring system. The general description of the measuring system usually comprises main data and capabilities of the measuring system, such as the rated operating voltage, waveform(s), range(s) of clearances, operating time, or maximum rate of voltage applications. For many measuring systems, information on the transmission system as well as high-voltage and ground-return arrangements are important. If required, a description is also given of components of the measuring system, including for example the type and identification of the measuring instrument. 4.3.4 Uncertainty The uncertainty of all measurements made under this International Standard shall be evaluated according to ISO/IEC Guide 98-3. Uncertainty of measurement shall be distinguished from the tolerance. A pass/fail decision is based solely on the measured value in relation to the pass/fail criteria. The measurement uncertainty shall not be applied to the measured value to make the pass/fail decision. Procedures for evaluating uncertainties given in 4.4.7 are specified in accordance with the principles of ISO/IEC Guide 98-3, and are considered sufficient for the instrumentation and measurement arrangements commonly used in high-voltage testing. However, users may select other appropriate procedures from ISO/IEC Guide 98-3, some of which are outlined in Annex A and Annex B. In general, the measurand to be considered is the scale factor of the measuring system, but in some cases other quantities, such as the time parameters of an impulse voltage and their associated errors, should also be considered. NOTE 1 Other measurands for specific converting devices are in common use. For example, a voltage divider is characterized by the voltage ratio and its uncertainty in the assigned measurement ranges used. A voltage transformer is characterized by the ratio error, the phase displacement and the corresponding uncertainties. SIST EN 61180:2017

– 16 – IEC 61180:2016 © IEC 2016 According to the ISO/IEC Guide 98-3, the uncertainty of a measurement is determined by combining the uncertainty contributions of Type A and Type B (see 4.4.7). These contributions are obtained from measurement results, manufacturers’ handbooks, calibration certificates and from estimating reasonable values of the influence quantities during the measurement. Influence quantities considered in 4.4 include temperature effects, influence of the load, dynamic behaviour of the measuring system and long and short term stability influence. Other effects, including limited resolution of the measuring instrument, may be included if necessary. The uncertainty shall be given as the expanded uncertainty for a coverage probability of approximately 95 % corresponding to a coverage factor k=2 under the assumption of a normal distribution. NOTE 2 In this International Standard, the uncertainties of the scale factor and of voltage measurement (4.4.1 to 4.4.6) are expressed by the relative uncertainties instead of the absolute uncertainty normally considered in the ISO/IEC Guide 98-3. 4.4 Tests and test requirements for an approved measuring system and its components 4.4.1 Calibration – Determination of the scale factor The assigned scale factor of the measuring system shall be determined by calibration according to the specified performance tests. The assigned scale factor is a single value for the assigned measurement range. If necessary, several assigned measurement ranges with different scale factors may be defined. Scale factor(s) is (are) determined for a c
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