Instrument transformers - Part 2: Additional requirements for current transformers

This part of IEC 61869 is applicable to newly manufactured inductive current transformers for use with electrical measuring instruments and/or electrical protective devices having rated frequencies from 15 Hz to 100 Hz.

Messwandler - Teil 2: Zusätzliche Anforderungen für Stromwandler

Transformateurs de mesure - Partie 2: Exigences supplémentaires concernant les transformateurs de courant

La CEI 61869-2:2012 s'applique aux transformateurs inductifs de courant fabriqués récemment et destinés à être utilisés avec des appareils de mesure électriques et/ou des dispositifs électriques de protection présentant une fréquence assignée comprise entre 15 Hz et 100 Hz. Cette Norme Internationale doit être utilisée conjointement avec la CEI 61869-1:2007, sur laquelle elle est basée. Cette Norme Internationale annule et remplace la première édition de la CEI 60044-1, publiée en 1996, et son Amendement 1 (2000) et Amendement 2  (2002), et la première édition de la CEI 60044-6 (1992). De plus, elle introduit des innovations techniques dans la normalisation et l'adaptation des exigences des transformateurs de courant pour réponse en régime transitoire.

Instrumentni transformatorji - 2. del: Dodatne zahteve za tokovne transformatorje

Ta del standarda IEC 61869 se uporablja za nove induktivne tokovne transformatorje, ki se uporabljajo v električnih merilnih instrumentih in/ali električnih zaščitnih napravah z naznačenimi frekvencami od 15 Hz do 100 Hz.

General Information

Status
Published
Publication Date
21-Jan-2013
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
11-Jan-2013
Due Date
18-Mar-2013
Completion Date
22-Jan-2013

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Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 61869-2:2013
01-marec-2013
1DGRPHãþD
SIST EN 60044-6:2001
Instrumentni transformatorji - 2. del: Dodatne zahteve za tokovne transformatorje
Instrument transformers - Part 2: Additional requirements for current transformers
Messwandler - Teil 2: Zusätzliche Anforderungen für Stromwandler
Transformateurs de mesure - Partie 2: Exigences supplémentaires concernant les
transformateurs de courant
Ta slovenski standard je istoveten z: EN 61869-2:2012
ICS:
17.220.20 0HUMHQMHHOHNWULþQLKLQ Measurement of electrical
PDJQHWQLKYHOLþLQ and magnetic quantities
SIST EN 61869-2:2013 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN 61869-2:2013

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

SIST EN 61869-2:2013

EUROPEAN STANDARD
EN 61869-2

NORME EUROPÉENNE
November 2012
EUROPÄISCHE NORM

ICS 17.220.20 Supersedes EN 60044-1:1999 + A1:2000 + A2:2003, EN 60044-6:1999


English version


Instrument transformers -
Part 2: Additional requirements for current transformers
(IEC 61869-2:2012)


Transformateurs de mesure -  Messwandler -
Partie 2: Exigences supplémentaires Teil 2: Zusätzliche Anforderungen für
concernant les transformateurs de courant Stromwandler
(CEI 61869-2:2012) (IEC 61869-2:2012)





This European Standard was approved by CENELEC on 2012-10-23. 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.

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

Management Centre: Avenue Marnix 17, B - 1000 Brussels


© 2012 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61869-2:2012 E

---------------------- Page: 3 ----------------------

SIST EN 61869-2:2013
EN 61869-2:2012 - 2 -

Foreword
The text of document 38/435/FDIS, future edition 1 of IEC 61869-2, prepared by IEC/TC 38, "Instrument
transformers" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
EN 61869-2:2012.

The following dates are fixed:
(dop) 2013-07-23
• latest date by which the document has
to be implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2015-10-23

standards conflicting with the
document have to be withdrawn

This document supersedes EN 60044-1:1999 + A1:2000 + A2:2003 and EN 60044-6:1999.
Additionally it introduces technical innovations in the standardization and adaptation of the requirements
for current transformers for transient performance.

This Part 2 is to be used in conjunction with, and is based on, EN 61869-1:2009, General Requirements –
however the reader is encouraged to use its most recent edition.
This Part 2 follows the structure of EN 61869-1:2009 and supplements or modifies its corresponding
clauses.
When a particular clause/subclause of Part 1 is not mentioned in this Part 2, that clause/subclause
applies as far as is reasonable. When this standard states “addition”, “modification” or “replacement”, the
relevant text in Part 1 is to be adapted accordingly.
For additional clauses, subclauses, figures, tables, annexes or notes, the following numbering system is
used:
– clauses, subclauses, tables, figures and notes that are numbered starting from 201 are additional to
those in Part 1;
– additional annexes are lettered 2A, 2B, etc.
Annex ZZ of EN 61869-1 is not applicable for this part of the series.
An overview of the planned set of standards at the date of publication of this document is given below.
The updated list of standards prepared by IEC TC38 is available at the website: www.iec.ch; the updated
list of standards prepared by IEC TC38 and approved by CENELEC is available at the website:
www.cenelec.eu.

---------------------- Page: 4 ----------------------

SIST EN 61869-2:2013
- 3 - EN 61869-2:2012

PRODUCT FAMILY STANDARDS PRODUCT PRODUCTS OLD
STANDARD STANDARD
ADDITIONAL REQUIREMENTS FOR 60044-1
61869-2

CURRENT TRANSFORMERS

ADDITIONAL REQUIREMENTS FOR 60044-2
61869-3
INDUCTIVE VOLTAGE TRANSFORMERS

 ADDITIONAL REQUIREMENTS FOR 60044-3
61869-4
COMBINED TRANSFORMERS

ADDITIONAL REQUIREMENTS FOR 60044-5
61869-5
 CAPACITIVE VOLTAGE TRANSFORMERS
61869-1
ADDITIONAL REQUIREMENTS FOR 60044-7
61869-6 61869-7
GENERAL
ELECTRONIC VOLTAGE TRANSFORMERS
REQUIREMENTS ADDITIONAL
GENERAL
FOR INSTRUMENT
ADDITIONAL REQUIREMENTS FOR 60044-8
61869-8
REQUIREMENT
TRANSFORMERS
ELECTRONIC CURRENT TRANSFORMERS
FOR ELECTRONIC
INSTRUMENT
TRANSFORMERS DIGITAL INTERFACE FOR INSTRUMENT
61869-9
AND LOW POWER TRANSFORMERS
STAND ALONE
SENSORS
ADDITIONAL REQUIREMENTS FOR LOW-
61869-10
POWER STAND-ALONE CURRENT SENSORS
ADDITIONAL REQUIREMENTS FOR LOW 60044-7
61869-11
POWER STAND ALONE VOLTAGE SENSOR
ADDITIONAL REQUIREMENTS FOR
61869-12

COMBINED ELECTRONIC INSTRUMENT
TRANSFORMER OR COMBINED STAND
ALONE SENSORS
STAND ALONE MERGING UNIT
61869-13

Since the publication of EN 60044-6 (Requirements for protective current transformers for transient
performance) in 1999, the area of application of this kind of current transformers has been extended. As a
consequence, the theoretical background for the dimensioning according to the electrical requirements
has become much more complex. In order to keep this standard as user-friendly as possible, the
explanation of the background information will be transferred to the Technical Report IEC/TR 61869-100,
which is now in preparation.
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.

This standard covers the Principle Elements of the Safety Objectives for Electrical Equipment Designed
for Use within Certain Voltage Limits (LVD - 2006/95/EC).

Endorsement notice
The text of the International Standard IEC 61869-2:2012 was approved by CENELEC as a European
Standard without any modification.

---------------------- Page: 5 ----------------------

SIST EN 61869-2:2013
EN 61869-2:2012 - 4 -
Annex ZA
(normative)

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

Addition to Annex ZA of EN 61869-1:2009:

Publication Year Title EN/HD Year

IEC 61869-1 (mod) 2007 Instrument transformers - EN 61869-1 2009
Part 1: General requirements

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

SIST EN 61869-2:2013



IEC 61869-2

®


Edition 1.0 2012-09




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE











Instrument transformers –

Part 2: Additional requirements for current transformers




Transformateurs de mesure –

Partie 2: Exigences supplémentaires concernant les transformateurs de courant
















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE

PRICE CODE
INTERNATIONALE

CODE PRIX XB


ICS 17.220.20 ISBN 978-2-83220-293-7



Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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

SIST EN 61869-2:2013
– 2 – 61869-2 © IEC:2012
CONTENTS
FOREWORD . 5
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
3.1 General definitions . 8
3.3 Definitions related to current ratings . 9
3.4 Definitions related to accuracy . 10
3.7 Index of abbreviations . 18
5 Ratings . 20
5.3 Rated insulation levels . 20
5.3.2 Rated primary terminal insulation level . 20
5.3.5 Insulation requirements for secondary terminals . 20
5.3.201 Inter-turn insulation requirements . 20
5.5 Rated output . 20
5.5.201 Rated output values . 20
5.5.202 Rated resistive burden values . 20
5.6 Rated accuracy class . 21
5.6.201 Measuring current transformers . 21
5.6.202 Protective current transformers . 22
5.6.203 Class assignments for selectable-ratio current transformers . 26
5.201 Standard values for rated primary current . 26
5.202 Standard values for rated secondary current . 27
5.203 Standard values for rated continuous thermal current . 27
5.204 Short-time current ratings . 27
5.204.1 Rated short-time thermal current (I ) . 27
th
5.204.2 Rated dynamic current (I ) . 27
dyn
6 Design and construction . 27
6.4 Requirements for temperature rise of parts and components . 27
6.4.1 General . 27
6.13 Markings . 27
6.13.201 Terminal markings . 27
6.13.202 Rating plate markings . 28
7 Tests . 30
7.1 General . 30
7.1.2 Lists of tests . 30
7.2 Type tests . 31
7.2.2 Temperature-rise test . 31
7.2.3 Impulse voltage withstand test on primary terminals . 33
7.2.6 Tests for accuracy . 33
7.2.201 Short-time current tests . 35
7.3 Routine tests . 36
7.3.1 Power-frequency voltage withstand tests on primary terminals . 36
7.3.5 Tests for accuracy . 36
7.3.201 Determination of the secondary winding resistance (R ) . 38
ct
7.3.202 Determination of the secondary loop time constant (T ) . 38
s

---------------------- Page: 8 ----------------------

SIST EN 61869-2:2013
61869-2 © IEC:2012 – 3 –
7.3.203 Test for rated knee point e.m.f. (E ) and exciting current at E . 39
k k
7.3.204 Inter-turn overvoltage test . 39
7.4 Special tests . 40
7.4.3 Measurement of capacitance and dielectric dissipation factor . 40
7.4.6 Internal arc fault test . 40
7.5 Sample tests . 41
7.5.1 Determination of the remanence factor . 41
7.5.2 Determination of the instrument security factor (FS) of
measuring current transformers . 41
Annex 2A (normative) Protective current transformers classes P, PR . 42
Annex 2B (normative) Protective current transformer classes for transient
performance . 47
Annex 2C (normative) Proof of low-leakage reactance type . 63
Annex 2D (informative) Technique used in temperature rise test of oil-immersed
transformers to determine the thermal constant by an experimental estimation . 64
Annex 2E (informative) Alternative measurement of the ratio error (ε) . 66
Annex 2F (normative) Determination of the turns ratio error . 68

Figure 201 – Duty cycles . 15
Figure 202 – Primary time constant T . 16
P
Figure 203 – Secondary linked flux for different fault inception angles γ . 17
Figure 2A.1 – Vector Diagram . 42
Figure 2A.2 – Error triangle . 43
Figure 2A.3 – Typical current waveforms . 44
Figure 2A.4 – Basic circuit for 1:1 current transformer . 44
Figure 2A.5 – Basic circuit for current transformer with any ratio. 45
Figure 2A.6 – Alternative test circuit . 45
Figure 2B.1 – Short-circuit current for two different fault inception angles . 48
Figure 2B.2 – ψ (t) as the curve of the highest flux values, considering all relevant
max
fault inception angles γ . 48
Figure 2B.3 – Relevant time ranges for calculation of transient factor . 49
Figure 2B.4 – Determination of K
in time range 1 at 50 Hz for T = 1,8 s . 50
tf s
Figure 2B.5 – Determination of K in time range 1 at 60 Hz for T = 1,5 s . 50
tf s
Figure 2B.6 – Determination of K in time range 1 at 16,7 Hz for T = 5.5 s . 50
tf s
Figure 2B.7 – Limiting the magnetic flux by considering core saturation . 52
Figure 2B.8 – Basic circuit . 53
Figure 2B.9 – Determination of remanence factor by hysteresis loop . 55
Figure 2B.10 – Circuit for d.c. method . 56
Figure 2B.11 – Time-amplitude and flux-current diagrams . 56
Figure 2B.12 – Recordings with shifted flux base line . 57
Figure 2B.13 – Circuit for capacitor discharge method . 58
Figure 2B.14 – Typical records for capacitor discharge method . 59
Figure 2B.15 – Measurement of error currents . 60
Figure 2D.1 – Graphical extrapolation to ultimate temperature rise . 65
Figure 2E.1 – Simplified equivalent circuit of the current transformer . 66

---------------------- Page: 9 ----------------------

SIST EN 61869-2:2013
– 4 – 61869-2 © IEC:2012

Table 201 – Limits of ratio error and phase displacement for measuring current
transformers (classes 0,1 to 1). 21
Table 202 – Limits of ratio error and phase displacement for measuring current
transformers (classes 0,2S and 0,5S) . 22
Table 203 – Limits of ratio error for measuring current transformers (classes 3 and 5) . 22
Table 204 – Characterisation of protective classes . 23
Table 205 – Error limits for protective current transformers class P and PR . 23
Table 206 – Error limits for TPX, TPY and TPZ current transformers. 25
Table 207 – Specification Methods for TPX, TPY and TPZ current transformers . 26
Table 208 – Marking of terminals . 28
Table 10 – List of tests . 31

---------------------- Page: 10 ----------------------

SIST EN 61869-2:2013
61869-2 © IEC:2012 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

INSTRUMENT TRANSFORMERS –

Part 2: Additional requirements for current transformers


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 closely 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.
This International Standard IEC 61869-2 Ed.1.0 has been prepared by committee 38:
Instrument transformers.
This first edition of IEC 61869-2 cancels and replaces the first edition of IEC 60044-1,
published in 1996, and its Amendment 1 (2000) and Amendment 2 (2002), and the first edition
of IEC 60044-6, published in 1992. Additionally it introduces technical innovations in the
standardization and adaptation of the requirements for current transformers for transient
performance.
The text of this standard is based on the following documents:
FDIS Report on voting
38/435/FDIS 38/437/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.

---------------------- Page: 11 ----------------------

SIST EN 61869-2:2013
– 6 – 61869-2 © IEC:2012
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all the parts in the IEC 61869 series, published under the general title Instrument
transformers, can be found on the IEC website.
This Part 2 is to be used in conjunction with, and is based on, IEC 61869-1:2007, General
Requirements – however the reader is encouraged to use its most recent edition.
This Part 2 follows the structure of IEC 61869-1:2007 and supplements or modifies its
corresponding clauses.
When a particular clause/subclause of Part 1 is not mentioned in this Part 2, that
clause/subclause applies as far as is reasonable. When this standard states “addition”,
“modification” or “replacement”, the relevant text in Part 1 is to be adapted accordingly.
For additional clauses, subclauses, figures, tables, annexes or notes, the following numbering
system is used:
– clauses, subclauses, tables, figures and notes that are numbered starting from 201 are
additional to those in Part 1;
– additional annexes are lettered 2A, 2B, etc.
An overview of the planned set of standards at the date of publication of this document is
given below. The updated list of standards issued by IEC TC38 is available at the website:
www.iec.ch.

---------------------- Page: 12 ----------------------

SIST EN 61869-2:2013
61869-2 © IEC:2012 – 7 –
PRODUCT FAMILY STANDARDS PRODUCT PRODUCTS OLD
STANDARD STANDARD
 ADDITIONAL REQUIREMENTS FOR 60044-1
61869-2
CURRENT TRANSFORMERS 60044-6

ADDITIONAL REQUIREMENTS FOR 60044-2
61869-3
INDUCTIVE VOLTAGE TRANSFORMERS

ADDITIONAL REQUIREMENTS FOR 60044-3
61869-4

COMBINED TRANSFORMERS

ADDITIONAL REQUIREMENTS FOR 60044-5
61869-5
CAPACITIVE VOLTAGE TRANSFORMERS

ADDITIONAL REQUIREMENTS FOR 60044-7
61869-6 61869-7
61869-1:2007
ELECTRONIC VOLTAGE
TRANSFORMERS
ADDITIONAL
GENERAL
GENERAL
REQUIREMENTS
REQUIREMENT ADDITIONAL REQUIREMENTS FOR 60044-8
61869-8
FOR
ELECTRONIC CURRENT
FOR
INSTRUMENT
TRANSFORMERS
ELECTRONIC
TRANSFORMERS
INSTRUMENT
TRANSFORMERS
DIGITAL INTERFACE FOR INSTRUMENT
61869-9
AND LOW
TRANSFORMERS
POWER STAND
ALONE
ADDITIONAL REQUIREMENTS FOR LOW-
61869-10
SENSORS
POWER STAND-ALONE CURRENT
SENSORS
ADDITIONAL REQUIREMENTS FOR LOW 60044-7
61869-11
POWER STAND ALONE VOLTAGE
SENSOR
ADDITIONAL REQUIREMENTS FOR
61869-12

COMBINED ELECTRONIC INSTRUMENT
TRANSFORMER OR COMBINED STAND
ALONE SENSORS
STAND ALONE MERGING UNIT
61869-13


Since the publication of IEC 60044-6 (Requirements for protective current transformers for
transient performance) in 1992, the area of application of this kind of current transformers has
been extended. As a consequence, the theoretical background for the dimensioning according
to the electrical requirements has become much more complex. In order to keep this standard
as user-friendly as possible, the explanation of the background information will be transferred
to the Technical Report IEC 61869-100 TR, which is now in preparation.
The committee has decided that the contents of this publication will remain unchanged until
the stability 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.

---------------------- Page: 13 ----------------------

SIST EN 61869-2:2013
– 8 – 61869-2 © IEC:2012
INSTRUMENT TRANSFORMERS –

Part 2: Additional requirements for Current Transformers



1 Scope
This part of IEC 61869 is applicable to newly manufactured inductive current transformers for
use with electrical measuring instruments and/or electrical protective devices having rated
frequencies from 15 Hz to 100 Hz.
2 Normative references
Clause 2 of IEC 61869-1:2007 is applicable with the following additions:
IEC 61869-1:2007, Instrument Transformers – Part 1: General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions in IEC 61869-1:2007 apply with
the following additions:
3.1 General definitions
3.1.201
current transformer
instrument transformer in which the secondary current, under normal conditions of use, is
substantially proportional to the primary current and differs in phase from it by an angle which
is approximately zero for an appropriate direction of the connections
[SOURCE: IEC 60050-321:1986, 321-02-01]
3.1.202
measuring current transformer
current transformer intended to transmit an information signal to measuring instruments and
meters
[SOURCE: IEC 60050-321:1986, 321-02-18]
3.1.203
protective current transformer
a current transformer intended to transmit an information signal to protective and control
devices
[SOURCE: IEC 60050-321: 1986, 321-02-19)
3.1.204
class P protective current transformer
protective current transformer without remanent flux limit, for which the saturation behaviour
in the ca
...

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