IEC 60990:2016
(Main)Methods of measurement of touch current and protective conductor current
Methods of measurement of touch current and protective conductor current
IEC 60990:2016 defines measurement methods for d.c. or a.c. current of sinusoidal or non-sinusoidal waveform, which could flow through the human body, and current flowing through a protective conductor. The measuring methods recommended for TOUCH CURRENT are based upon the possible effects of current flowing through a human body. In this standard, measurements of current through networks representing the impedance of the human body are referred to as measurements of TOUCH CURRENT. These networks are not necessarily valid for the bodies of animals. The specification or implication of specific limit values is not within the scope of this standard. IEC TS 60479 series provides information regarding the effects of current passing through the human body from which limit values may be derived. This standard is applicable to all classes of EQUIPMENT, according to IEC 61140. The methods of measurement in this standard are not intended to be used for TOUCH CURRENTS having less than 1 s duration, patient currents as defined in IEC 60601-1, a.c. at frequencies below 15 Hz, and currents above those chosen for ELECTRIC BURN limits. This third edition cancels and replaces the second edition published in 1999. It constitutes a technical revision. The principal changes in this edition as compared with the second edition are as follows:
- the effects names have been updated to reflect increased understanding of the range of effects and is in concert with present usage;
- the conditions of use invoking a GRIPPABLE PART have been reduced in the application of the requirements based upon the current understanding of this effect;
- the references to ISO 10012-1, which has been replaced by management standard of the same number, have been replaced with explanatory text, where needed to maintain the sense of the document;
- former informative Annex H (GRIPPABLE PART) has been deleted from this update as it does not properly represent the full set of conditions under which immobilization can occur. A new informative Annex H (Analysis of frequency filtered touch current circuits measurement) has been added and the Bibliography (formerly Annex M) has been updated with additional references for completeness.
This basic safety publication is primarily intended for use by technical committees in the preparation of standards in accordance with IEC Guide 104 and ISO/IEC Guide 51. It is not intended for use by manufacturers or certification bodies independent of product standards.
It has the status of a Basic Safety Publication in accordance with IEC Guide 104.
Key words: Touch Current, Protective Conductor Current, Current Flow
Méthodes de mesure du courant de contact et du courant dans le conducteur de protection
L'IEC 60990:2016 définit des méthodes de mesure pour les courants continus ou les courants alternatifs de forme d'onde sinusoïdale ou non sinusoïdale qui peuvent traverser le corps humain, et les courants qui peuvent circuler dans un conducteur de protection. Les méthodes de mesure recommandées pour le COURANT DE CONTACT sont basées sur les effets possibles provoqués par le passage du courant dans le corps humain. Dans la présente norme, les mesurages de courant à travers des réseaux représentant l'impédance du corps humain sont appelés mesurages du COURANT DE CONTACT. Les réseaux utilisés ne sont pas nécessairement valables pour des animaux. La spécification ou l'implication de valeurs limites spécifiques ne fait pas partie du domaine d'application de la présente norme. La série IEC TS 60479 fournit des informations concernant les effets du courant traversant le corps humain, à partir desquelles des valeurs limites peuvent être déduites. La présente norme est applicable à toutes les classes de MATERIELS, conformément à l'IEC 61140. Les méthodes de mesure indiquées dans la présente norme ne sont pas destinées à être utilisées pour les COURANTS DE CONTACT de durée inférieure à 1 s, les courants patients tels qu'ils sont définis dans l'IEC 60601-1, les courants alternatifs de fréquence inférieure à 15 Hz, et les courants supérieurs aux courants choisis pour les limites de BRULURE ELECTRIQUE. Cette troisième édition annule et remplace la deuxième édition, parue en 1999. Cette édition constitue une révision technique. Cette édition inclut les modifications majeures suivantes par rapport à la deuxième édition:
- les désignations des effets ont été mises à jour pour refléter la meilleure compréhension de la plage des effets et s'accorder avec l'utilisation actuelle;
- les conditions d'utilisation impliquant une PARTIE PREHENSIBLE ont été réduites pour l'application des exigences fondées sur la compréhension actuelle de cet effet;
- les références à l'ISO 10012-1, qui a été remplacée par une norme de management portant le même numéro, ont été remplacées par un texte explicatif, le cas échéant, afin de conserver le sens du document;
- l'ancienne Annexe H informative (PARTIE PREHENSIBLE) a été supprimée de cette mise à jour car elle ne représente pas de manière adéquate l'intégralité des conditions dans lesquelles une immobilisation est susceptible de se produire. Une nouvelle Annexe H informative (Analyse du mesurage de circuits de courant de contact avec filtre de fréquence) a été ajoutée et la Bibliographie (anciennement dénommée Annexe M) a été mise à jour avec des références supplémentaires par souci d'exhaustivité. La présente publication fondamentale de sécurité est destinée principalement à être utilisée par les comités d'études lors de la préparation de normes conformément au IEC Guide 104 et le Guide ISO/IEC 51. Elle n'est pas destinée à être utilisée par les fabricants ou les organismes de certification indépendants de normes de produit. Mots-clés: courant de contact, courant dans le conducteur de protection, passage du courant
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IEC 60990 ®
Edition 3.0 2016-05
REDLINE VERSION
INTERNATIONAL
STANDARD
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BASIC SAFETY PUBLICATION
Methods of measurement of touch current and protective conductor current
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
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About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
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and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and
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IEC 60990 ®
Edition 3.0 2016-05
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
BASIC SAFETY PUBLICATION
Methods of measurement of touch current and protective conductor current
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 17.220, 35.020 ISBN 978-2-8322-3449-5
– 2 – IEC 60990:2016 RLV © IEC 2016
CONTENTS
FOREWORD . 6
INTRODUCTION . 8
1 Scope . 11
2 Normative references . 11
3 Terms and definitions. 12
4 Test site . 13
4.1 Test site environment . 13
4.2 Test transformer . 13
4.3 Earthed neutral conductor . 13
5 Measuring equipment . 14
5.1 Selection of measuring network . 14
5.1.1 General . 14
5.1.2 Perception and startle-reaction (a.c.) . 16
5.1.3 Letgo-immobilization (a.c.) . 16
5.1.4 Electric burn (a.c.) . 16
5.1.5 Ripple-free d.c. . 16
5.2 Test electrodes . 17
5.2.1 Construction . 17
5.2.2 Connection . 17
5.3 Configuration . 17
5.4 Power connections during test . 17
5.4.1 General . 17
5.4.2 Equipment for use only on TN or TT star power distribution systems . 22
5.4.3 Equipment for use on IT power distribution systems including unearthed
delta systems . 22
5.4.4 Equipment for use on single-phase centre-earthed power supply systems
or on centre-earthed delta power supply systems . 22
5.5 Supply voltage and frequency . 22
5.5.1 Supply voltage . 22
5.5.2 Supply frequency . 23
6 Test procedure . 23
6.1 General . 23
6.1.1 Touch current measurements . 23
6.1.2 Control switches, equipment and supply conditions . 23
6.1.3 Use of measuring networks . 24
6.2 Normal and fault conditions of equipment . 24
6.2.1 Normal operation of equipment . 24
6.2.2 Equipment and supply fault conditions . 24
7 Evaluation of results . 26
7.1 Perception, startle-reaction and letgo-immobilization . 26
7.2 Electric burn . 26
8 Measurement of protective conductor current . 26
8.1 General . 26
8.2 Multiple equipment . 26
8.3 Measuring method . 27
Annex A (normative) Equipment . 28
Annex B (normative) Use of a conductive plane . 29
Annex C (normative) Incidentally connected parts . 30
Annex D (informative) Choice of current limits . 31
D.1 General . 31
D.2 Limit examples . 31
D.2.1 Ventricular fibrillation . 31
D.2.2 Inability to letgo-immobilization . 31
D.2.3 Startle-reaction . 31
D.2.4 Perception threshold . 31
D.2.5 Special applications . 31
D.3 Choice of limits . 32
D.4 Electric burn effects of touch current . 33
Annex E (informative) Networks for use in measurement of touch current . 34
E.1 General . 34
E.2 Body impedance network – Figure 3 . 34
E.3 Perception, Startle-reaction (and body impedance) network – Figure 4 . 34
E.4 Letgo-immobilization (and body impedance) network – Figure 5 . 35
Annex F (informative) Measuring network limitations and construction . 36
Annex G (informative) Construction and application of touch current measuring
instruments . 38
G.1 Considerations for selection of components . 38
G.1.1 General . 38
G.1.2 Power rating and inductance for R and R . 38
S B
G.1.3 Capacitor C . 38
S
G.1.4 Resistors R1, R2 and R3 . 39
G.1.5 Capacitors C1, C2 and C3 . 39
G.2 Voltmeter . 39
G.3 Accuracy . 39
G.4 Calibration and application of measuring instruments . 40
G.5 Records . 40
G.6 Confirmation systems . 41
Annex H (informative) Grippable part .
Annex H (informative) Analysis of frequency filtered touch current circuit measurements . 44
Annex I (informative) AC power distribution systems (see 5.4) . 52
I.1 Introduction General . 52
I.2 TN power systems . 53
I.3 TT power systems . 56
I.4 IT power systems . 57
Annex J (informative) Routine and periodic touch current tests, and tests after repair
or modification of mains operated equipment . 59
Annex K (normative) Network performance and calibration . 60
K.1 Network or instrument performance and initial calibration . 60
K.2 Calibration in a confirmation system . 62
K.2.1 General . 62
K.2.2 Measurement of input resistance . 62
K.2.3 Measurement of instrument performance . 62
– 4 – IEC 60990:2016 RLV © IEC 2016
Annex M (informative) Bibliography . 65
Figure 1 – Example of earthed neutral, direct supply .
...
IEC 60990 ®
Edition 3.0 2016-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Methods of measurement of touch current and protective conductor current
Méthodes de mesure du courant de contact et du courant dans le conducteur de
protection
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
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Switzerland www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
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The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 20 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 15 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.
IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 65 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and
CISPR.
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IEC 60990 ®
Edition 3.0 2016-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
BASIC SAFETY PUBLICATION
PUBLICATION FONDAMENTALE DE SÉCURITÉ
Methods of measurement of touch current and protective conductor current
Méthodes de mesure du courant de contact et du courant dans le conducteur de
protection
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220, 35.020 ISBN 978-2-8322-3420-4
– 2 – IEC 60990:2016 © IEC 2016
CONTENTS
FOREWORD .6
INTRODUCTION .8
1 Scope . 10
2 Normative references . 10
3 Terms and definitions . 11
4 Test site . 11
4.1 Test site environment . 11
4.2 Test transformer . 12
4.3 Earthed neutral conductor . 12
5 Measuring equipment . 13
5.1 Selection of measuring network . 13
5.1.1 General . 13
5.1.2 Perception and startle-reaction . 14
5.1.3 Letgo-immobilization . 14
5.1.4 Electric burn (a.c.) . 14
5.1.5 Ripple-free d.c. . 14
5.2 Test electrodes . 15
5.2.1 Construction . 15
5.2.2 Connection . 15
5.3 Configuration . 15
5.4 Power connections during test . 15
5.4.1 General . 15
5.4.2 Equipment for use only on TN or TT star power distribution systems . 19
5.4.3 Equipment for use on IT power distribution systems including
unearthed delta systems . 19
5.4.4 Equipment for use on single-phase centre-earthed power supply
systems or on centre-earthed delta power supply systems . 20
5.5 Supply voltage and frequency . 20
5.5.1 Supply voltage . 20
5.5.2 Supply frequency . 20
6 Test procedure . 20
6.1 General . 20
6.1.1 Touch current measurements . 20
6.1.2 Control switches, equipment and supply conditions . 21
6.1.3 Use of measuring networks . 21
6.2 Normal and fault conditions of equipment . 21
6.2.1 Normal operation of equipment . 21
6.2.2 Equipment and supply fault conditions . 21
7 Evaluation of results . 23
7.1 Perception, startle-reaction and letgo-immobilization . 23
7.2 Electric burn . 23
8 Measurement of protective conductor current . 23
8.1 General . 23
8.2 Multiple equipment . 24
8.3 Measuring method . 24
Annex A (normative) Equipment . 25
Annex B (normative) Use of a conductive plane . 26
Annex C (normative) Incidentally connected parts . 27
Annex D (informative) Choice of current limits . 28
D.1 General . 28
D.2 Limit examples . 28
D.2.1 Ventricular fibrillation . 28
D.2.2 Inability to letgo-immobilization . 28
D.2.3 Startle-reaction . 28
D.2.4 Perception threshold . 28
D.2.5 Special applications . 28
D.3 Choice of limits . 29
D.4 Electric burn effects of touch current . 30
Annex E (informative) Networks for use in measurement of touch current . 31
E.1 General . 31
E.2 Body impedance network – Figure 3 . 31
E.3 Startle-reaction (and body impedance) network – Figure 4 . 31
E.4 Letgo-immobilization (and body impedance) network – Figure 5 . 32
Annex F (informative) Measuring network limitations and construction . 33
Annex G (informative) Construction and application of touch current measuring
instruments . 35
G.1 Considerations for selection of components . 35
G.1.1 General . 35
G.1.2 Power rating and inductance for R and R . 35
S B
G.1.3 Capacitor C .
...
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