IEC 60044-8:2002

INTERNATIONAL IEC
STANDARD
60044-8
First edition
2002-07
Instrument transformers –
Part 8:
Electronic current transformers
Transformateurs de mesure –
Partie 8:
Transformateurs de courant électroniques
Reference number
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INTERNATIONAL IEC
STANDARD
60044-8
First edition
2002-07
Instrument transformers –
Part 8:
Electronic current transformers
Transformateurs de mesure –
Partie 8:
Transformateurs de courant électroniques
 IEC 2002  Copyright - all rights reserved
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 the publisher.
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International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – 60044-8  IEC:2002(E)
CONTENTS
FOREWORD . 6
1 Scope . 7
1.1 General . 7
1.2 General block diagram of electronic current transformers . 8
1.3 General block diagram of electronic transformers with a digital output . 9
2 Normative references. 9
3 Definitions.12
3.1 General definitions.12
3.2 Additional definitions for measuring electronic current transformers.19
3.3 Additional definitions for protective electronic current transformers.19
3.4 Additional definitions for digital output .22
3.5 Additional definitions for analogue voltage output .23
3.6 Index of main definitions and abbreviations .23
4 Normal and special service conditions .24
4.1 General .24
4.2 Normal service conditions .25
4.3 Special service conditions .26
4.4 System earthing.28
5 Ratings .28
5.1 General ratings .28
5.2 Standard values for rated phase offset .32
5.3 Rating for digital output .32
5.4 Rating for analogue voltage output .33
6 Design requirements .34
6.1 General design requirements .34
6.2 Design requirements for digital output .43
6.3 Design requirements for analogue voltage output .60
7 Classification of tests .60
7.1 General .60
7.2 Type tests.60
7.3 Routine tests.61
7.4 Special tests .62
8 Type test.62
8.1 Short-time current tests.62
8.2 Temperature-rise test.63
8.3 Impulse tests on primary terminals .63
8.4 Wet test for outdoor type electronic current transformers.65
8.5 RIV tests.65
8.6 Transmitted overvoltage test .65
8.7 Low-voltage components voltage withstand test.66
8.8 EMC tests.67
8.9 Accuracy test .70
8.10 Additional accuracy tests for protective electronic current transformers .72
8.11 Verification of the protection.72
8.12 Tightness tests .73
8.13 Vibration tests.73
8.14 Additional type test for digital output.74

60044-8  IEC:2002(E) – 3 –
9 Routine tests.75
9.1 Verification of terminal markings .75
9.2 Power-frequency withstand tests on primary terminals
and partial discharge measurement.75
9.3 Power-frequency voltage withstand test for low-voltage components.75
9.4 Accuracy tests .75
9.5 Tightness tests .75
9.6 Additional routine tests for digital output .76
9.7 Additional routine tests for analogue output .76
10 Special tests .76
10.1 Chopped lightning-impulse test on primary terminals .76
10.2 Measurement of capacitance and dielectric dissipation factor .76
10.3 Mechanical tests .76
10.4 Tests for accuracy versus harmonics .77
10.5 Tests in accordance with the technology applied .78
11 Marking.78
11.1 Terminal marking – General rules .78
11.2 Rating plate markings .79
12 Additional requirements for measuring electronic current transformers .82
12.1 Accuracy class designation .82
12.2 Limits of current error and phase error at rated frequency.82
12.3 Accuracy requirements on harmonics .83
13 Additional requirements for protective electronic current transformers .83
13.1 Accuracy classes .83
13.2 Accuracy requirements on harmonics .84
14 Information to be given with enquiries, tenders and orders.84
14.1 Designation.84
14.2 Dependability.85
15 Rules for transport, storage and installation.85
15.1 Conditions during transport, storage and installation.86
15.2 Installation .86
15.3 Unpacking and lifting.86
15.4 Assembly.86
15.5 Operation.87
15.6 Maintenance .87
16 Safety .90
16.1 Electrical aspects.90
16.2 Mechanical aspects.90
16.3 Thermal aspects .90
Annex A (informative) Transient performances of ECTs .91
Annex B (informative) Technical information for electronic current transformers
with digital output .98
Annex C (informative) Technical information for electronic current transformers
with analogue output .108
Annex D (normative) Frequency response and accuracy requirements on harmonics for
electronic current and voltage transformer .116
Annex E (informative) Graph explaining the accuracy requirements.123

– 4 – 60044-8  IEC:2002(E)
Bibliography .124
Figure 1 – General block diagram of a single-phase electronic current transformer . 8
Figure 2 – Example of digital interface block diagram. 9
Figure 3 – Altitude correction factor .27
Figure 4 – Manchester coding.43
Figure 5 – Characteristics of
...