EN 61000-4-24:1997

SLOVENSKI STANDARD
01-november-1997
Electromagnetic compatibility (EMC) - Part 4: Testing and measurement
techniques - Section 24: Test methods for protective devices for HEMP conducted
disturbances - Basic EMC publication (IEC 61000-4-24:1997)
Electromagnetic compatibility (EMC) -- Part 4: Testing and measurement techniques --
Section 24: Test methods for protective devices for HEMP conducted disturbance
Elektromagnetische Verträglichkeit (EMV) -- Teil 4: Prüf- und Meßverfahren --
Hauptabschnitt 24: Prüfverfahren für Einrichtungen zum Schutz gegen leitungsgeführte
HEMP-Störgrößen
Compatibilité électromagnétique (CEM) -- Partie 4: Techniques d'essai et de mesure --
Section 24: Méthodes d'essais pour les dispositifs de protection pour perturbations
conduites IEMN-HA
Ta slovenski standard je istoveten z: EN 61000-4-24:1997
ICS:
33.100.20 Imunost Immunity
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

NORME
CEI
INTERNATIONALE
IEC
61000-4-24
INTERNATIONAL
Première édition
STANDARD
First edition
1997-02
Compatibilité électromagnétique (CEM) –
Partie 4:
Techniques d’essai et de mesure –
Section 24: Méthodes d’essais pour les dispositifs
de protection pour perturbations conduites IEMN-HA
Publication fondamentale en CEM
Electromagnetic compatibility (EMC) –
Part 4:
Testing and measurement techniques –
Section 24: Test methods for protective devices
for HEMP conducted disturbance
Basic EMC publication
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61000-4-24  IEC:1997 – 3 –
CONTENTS
Page
FOREWORD . 5
INTRODUCTION. 7
Clause
1 Scope . 9
2 Normative references. 9
3 Definitions. 9
4 Test methods for protective devices for conducted disturbance. 9
4.1 General. 9
4.2 Test set-up. 11
4.3 Pulse generator. 11
4.4 Launching line. 13
4.5 Test fixture. 13
4.5.1 General. 13
4.5.2 Type A fixtures. 13
4.5.3 Type B fixtures. 13
4.6 Termination. 15
4.7 Oscilloscope. 17
4.8 Test procedure. 17
4.8.1 Adjustment of the pulse generator. 17
4.8.2 Verification procedures. 17
4.8.3 Test. 19
4.8.4 Final examination of the DUT . 19
4.9 Referring to this standard. 19
Annex A – Bibliography . 21

61000-4-24  IEC:1997 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_________
ELECTROMAGNETIC COMPATIBILITY (EMC) –
Part 4: Testing and measurement techniques –
Section 24: Test methods for protective devices
for HEMP conducted disturbance
Basic EMC publication
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61000-4-24 has been prepared by subcommittee 77C: Immunity to
high-altitude nuclear electromagnetic pulse (HEMP), of IEC technical committee 77: Electro-
magnetic compatibility.
It forms section 24 of part 4 of IEC 61000. It has the status of a basic EMC publication in
accordance with IEC Guide 107.
The text of this standard is based on the following documents:
FDIS Report on voting
77C/37/FDIS 77C/40/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.
Annex A is for information only.

61000-4-24  IEC:1997 – 7 –
INTRODUCTION
The IEC has initiated the preparation of standardized methods to protect civilian society from
the effects of high-altitude nuclear bursts. Such effects could disrupt systems for
communications, electric power, information technology, etc.
This section of IEC 61000-4 is part of a complete set of standards that covers the entire
category of immunity to high-altitude nuclear electromagnetic pulse. The appropriate acronym
is either HA-NEMP or more simply HEMP.
The application of this standard is, however, not dependent on access to other sections and
parts of the IEC 1000 and IEC 61000, except for those specifically referred to.
Attention is drawn to IEC 1000-5-5.

61000-4-24  IEC:1997 – 9 –
ELECTROMAGNETIC COMPATIBILITY (EMC) –
Part 4: Testing and measurement techniques –
Section 24: Test methods for protective devices
for HEMP conducted disturbance
Basic EMC publication
1 Scope
This section of IEC 61000-4 deals with methods for testing protective devices for HEMP
conducted disturbance. It primarily covers testing of voltage breakdown and voltage-limiting
characteristics but also methods to measure the residual voltage under HEMP conditions for
the case of very fast changes of voltage (u) and current (i) as a function of time.
2 Normative references
The following normative document contains provisions which, through reference in this text,
constitute provisions of this section of IEC 61000-4. At the time of publication, the edition
indicated was valid. All normative documents are subject to revision, and parties to agreements
based on this section of IEC 61000-4 are encouraged to investigate the possibility of applying
the most recent edition of the normative document indicated below. Members of IEC and ISO
maintain registers of currently valid International Standards.
IEC 50(161): 1990, International Electrotechnical Vocabulary (IEV) – Chapter 161: Electro-
magnetic compatibility
3 Definitions
For the purposes of this section of IEC 61000-4, the following definitions apply:
3.1 DUT: Device under test
3.2 gas discharge tube: A gap, or several gaps with two or three metal electrodes
hermetically sealed so that gas mixture and pressure are under control, designed to protect
apparatus or personnel from high transient voltages.
3.3 primary protection element: First protective element seen from the unprotected side of
a protection measure, diverting the main part of the surge current.
3.4 protected side: The side of a protection measure where the equipment is situated that
has to be protected.
3.5 unprotected side: The side of a protection measure from which the surge event is expected.
4 Test methods for protective devices for conducted disturbance
4.1 General
The actual behaviour of a protective device under HEMP conditions depends very much on
how it is integrated in its place of use and other attendant circumstances (e.g. quality of
shielding between protected and unprotected side of a protection element). The following
test methods take this into account. They are defined so that the results obtained are as far
as possible related to the qualities of the device under test (DUT), and the test arrangement
does not differ too much from practical protection arrangements. In order to keep this test

61000-4-24  IEC:1997 – 11 –
standard simple and as universally applicable as possible, the performer is allowed to
optimize the test set-up within certain limits but without leaving the range of practical protection
arrangements.
4.2 Test set-up
The test set-up consists of pulse generator (G), launching line, test fixture for the DUT, and
termination with connecting line and oscilloscope (see figure 1). The characteristic impedance
shall be the same throughout the test set-up. If impedances other than 50 Ω are used, they
shall be specified.
50 Ω
Pulse-generator
Oscilloscope
Connecting line       Termination
G
Launching line
50 Ω
50 Ω
Test fixture with DUT
Unprotected side
Protected side
IEC  245/97
Figure 1 – Test set-up for testing protective devices
To prevent parasitic coupling between the pulse generator and the oscilloscope, both the
unprotected and protected side of the set-up must be entirely shielded. It is recommended to
use cables with multiple braided wire shields or solid shields. Be sure to use high-quality
coaxial connectors with the right characteristic impedance, that can withstand the high-voltage
pulses. Be aware of grounding loops.
4.3 Pulse generator
The pulse generator shall have a characteristic impedance of 50 Ω or the value specified. It
shall produce a normally rectangular voltage pulse into a matched termination. The front of the
wave shall have a rate-of-rise of at least 1 kV/ns at the firing voltage or limiting voltage of the
primary protection element of the DUT. The output voltage (into a matched termination) shall
be adjustable to a value 2 times higher than the expected limiting voltage of the DUT. Both
polarities shall be available. The pulse duration shall be at least 20 ns long.

61000-4-24  IEC:1997 – 13 –
4.4 Launching line
The launching line consists of a coaxial cable with a characteristic impedance of 50 Ω or the
value specified. The cable between the pulse generator and the DUT shall be long enough so
that reflections from the DUT do not arrive at the pulse generator during the pulse front. To
achieve this condition, the one- way propagation time along the cable must be greater than half
the front time of the pulse. Due to the frequency-dependent attenuation of the cable, the
steepness
...