SIST-TP IEC/TR 60725:2008

Consideration of reference impedances and public supply network impedances for use in determining disturbance characteristics of electrical equipment having a rated current = < 75 A per phase

This technical report records the information that was available and the factors that were taken into account in arriving at the reference impedances that were formerly incorporated in IEC 60555, but which are now incorporated into some sections of IEC 61000-3.[
]In addition, information is given on the impedances of public supply networks associated with service current capacities >=100 A per phase.

Etude des impédances de référence et des impédances des réseaux publics d'alimentation aux fins de la détermination des caractéristiques de perturbation des équipements électriques utilisant un courant nominal = < 75 A par phase

Ce rapport technique consigne les informations disponibles et les facteurs pris en compte lors du calcul des impédances de référence énoncées dans la CEI 60555, désormais intégrés à certaines sections de la CEI 61000-3.[
]De plus, les informations fournies concernent les impédances des réseaux publics de distribution associés à des courants de service ayant une capacité >=100 A par phase.

Ugotovitve o referenčnih impedancah in impedancah javnega napajalnega omrežja za določanje značilnosti motenj električne opreme z nazivnim faznim tokom do vključno 75 A

General Information

• Status: Withdrawn
• Public Enquiry End Date: 30-Sep-2008
• Publication Date: 01-Oct-2008
• Withdrawal Date: 17-Mar-2025
• ICS: 33.100.10 - Emission
• Technical Committee: EMC - Electromagnetic compatibility
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 18-Mar-2025
• Due Date: 10-Apr-2025
• Completion Date: 18-Mar-2025
• Ref Project: IEC/TR 60725 - Consideration of reference impedances and public supply network impedances for use in determining disturbance characteristics of electrical equipment having a rated current = < 75 A per phase

Relations

• Replaces: SIST IEC/TR 60725:1998 - Considerations on reference impedances for use in determining the disturbance characteristics of household appliances and similar electrical equipment
• Effective Date: 01-Nov-2008

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2008
1DGRPHãþD
SIST IEC/TR 60725:1998
8JRWRYLWYHRUHIHUHQþQLKLPSHGDQFDKLQLPSHGDQFDKMDYQHJDQDSDMDOQHJDRPUHåMD
]DGRORþDQMH]QDþLOQRVWLPRWHQMHOHNWULþQHRSUHPH]QD]LYQLPID]QLPWRNRPGR
YNOMXþQR$
Consideration of reference impedances and public supply network impedances for use in
determining disturbance characteristics of electrical equipment having a rated current = <
75 A per phase
Etude des impédances de référence et des impédances des réseaux publics
d'alimentation aux fins de la détermination des caractéristiques de perturbation des
équipements électriques utilisant un courant nominal = < 75 A par phase
Ta slovenski standard je istoveten z: IEC/TR 60725
ICS:
33.100.10 Emisija Emission
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

RAPPORT CEI
TECHNIQUE IEC
TR 60725
TECHNICAL
Deuxième édition
REPORT
Second edition
2005-05
Etude des impédances de référence et des
impédances des réseaux publics d'alimentation
aux fins de la détermination des caractéristiques
de perturbation des équipements électriques
utilisant un courant nominal ≤75 A par phase

Consideration of reference impedances and public
supply network impedances for use in determining
disturbance characteristics of electrical equipment
having a rated current ≤75 A per phase
 IEC 2005 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 any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale S
PRICE CODE
International Electrotechnical Commission
Международная Электротехническая Комиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

TR 60725  IEC:2005 – 3 –
CONTENTS
FOREWORD.5

1 Scope.9
2 Normative references .9
3 Systems of supply .9
4 Supply impedances .11
5 Reference impedances .17
6 Harmonic impedance.21

Annex A (informative) Methods for determining the maximum modulus values of public
electricity supply low-voltage network impedances relevant to three-phase services of
more than 100 A per phase at 50 Hz.23
Annex B (informative) Methods for determining the maximum modulus values of public
electricity supply low-voltage network impedances relevant to three-phase services of
more than 100 A per phase at 60 Hz.41

Figure A.1 – Model used for determining the impedance of a network line conductor
from a transformer to a three-phase service cut-out .27
Figure A.2 – The three-phase impedance diagram of a typical 500 kVA transformer
and mains cable.29

Table 1 – 1980 International survey of residential consumers’ complex supply
impedances, in ohms, for single-phase connections at 50 Hz.13
Table 2 – Modulus values of supply impedance, in ohms at 50 Hz, relevant to the
connection of three-phase equipment and having a 95 % probability of not being
exceeded.15
Table 3 – Modulus values of supply impedance, in ohms at 50 Hz, relevant to the
connection of single-phase equipment and having a 95 % probably of not being
exceeded.17
Table A.1 – The modulus values of the maximum supply impedance, in ohms, of the
line-conductors of 230/400 V, 50 Hz, public electricity supply networks, relevant to
three-phase services having service capacities of 200 A per phase .35
Table A.2 – The modulus values of the maximum supply impedance, in ohms, of the
line and neutral conductors of 230/400 V, 50 Hz, public electricity supply networks,
relevant to three-phase services having service capacities of 200 A per phase.35

TR 60725  IEC:2005 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
CONSIDERATION OF REFERENCE IMPEDANCES AND PUBLIC SUPPLY
NETWORK IMPEDANCES FOR USE IN DETERMINING DISTURBANCE
CHARACTERISTICS OF ELECTRICAL EQUIPMENT HAVING A RATED
CURRENT ≤ 75A PER PHASE
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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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.
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
IEC 60725, which is a technical report, has been prepared by subcommittee 77A: Low
frequency phenomena, of IEC technical committee 77: Electromagnetic compatibility.
This second edition cancels and replaces the first edition published in 1981. This second
edition constitutes a technical revision in which the major change is the definition of a method
to assess the 3 phase-impedance value in order to apply more easily IEC 61000-3-11.

TR 60725  IEC:2005 – 7 –
The text of this technical report is based on the following documents:
DTR Report on voting
77A/460/DTR 77A/485/RVC
Full information on the voting for the approval of this technical report 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.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result 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.
TR 60725  IEC:2005 – 9 –
CONSIDERATION OF REFERENCE IMPEDANCES AND PUBLIC SUPPLY
NETWORK IMPEDANCES FOR USE IN DETERMINING DISTURBANCE
CHARACTERISTICS OF ELECTRICAL EQUIPMENT HAVING A RATED
CURRENT ≤ 75A PER PHASE
1 Scope
This technical report records the information that was available and the factors that were
taken into account in arriving at the reference impedances that were formerly incorporated in
)
IEC 60555 , but which are now incorporated into some sections of IEC 61000-3.
In addition, information is given on the impedances of public supply networks associated with
service current capacities ≥100 A per phase.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 61000-3-3, Electromagnetic compatibility (EMC) – Part 3: Limits – Section 3: Limitation of
voltage fluctuations and flicker in low-voltage supply systems for equipment with rated current
2)
≤ 16 A
Amendment 1 (2001)
IEC 61000-3-11, Electromagnetic compatibility (EMC) – Part 3-11: Limits – Limitation of
voltage changes, voltage fluctuations and flicker in public low-voltage supply systems –
Equipment with rated current ≤ 75 A and subject to conditional connection
IEC 61000-3-12, Electromagnetic compatibility (EMC) – Part 3-12: Limits – Limits for
harmonic currents produced by equipment connected to public low-voltage systems with input
current > 16 A and ≤ 75 A per phase
3 Systems of supply
3.1 Three-phase supply systems
Three-phase, four-wire, distribution systems are used worldwide to supply low-voltage
consumers, with nominal voltages in the region of 230/400 V.
To conform with IEC standard voltages, these system are described as 230/400 V throughout
this report.
___________
)
IEC 60555 (all parts), Disturbances in supply systems caused by household appliances and similar electrical
equipment (withdrawn)
2)
A consolidated edition 1.1 (2002) exists, including IEC 61000-3-3:1994 and its Amendment 1 (2001). It has
been published under the title of Electromagnetic compatibility (EMC) – Part 3-3: Limits – Limitation of voltage
changes, voltage fluctuations and flicker in public low-voltage supply systems, for equipment with rated current
≤16 A per phase and not subject to conditional connection

TR 60725  IEC:2005 – 11 –
There is considerable variation in the way in which the supplies to individual consumers are
connected to three-phase systems.
In some countries, all four wires are taken into the consumer’s premises, allowing the use of
three-phase 400 V for large loads, with small appliances and lighting circuits connected
between one line and neutral at 230 V.
In other countries, three wires are taken into the consumer’s premises, allowing the use of
400 V across two phases for large loads, with small appliances and lighting circuits connected
between one line and neutral at 230 V.
In other countries, of which the United Kingdom is an example, it is unusual to take more than
one phase into a residential consumer’s premises. Consequently both large loads less than
15 kVA and lighting circuits are supplied between line and neutral at 230 V.
3.2 Single-phase supply systems
In some countries, of which the United States of America and Japan are examples, a single-
phase, three-wire distribution is used. Large loads are connected across the outer wires at
230 V whilst small appliances and lighting circuits are connected between one outer and the
centre wire at 115 V. This leads to quite different supply impedances from those of three-
phase distribution systems and may require different reference impedances.
Recommended values
...