SIST IEC 60479-2:2020
Effects of current on human beings and livestock - Part 2: Special aspects
Effects of current on human beings and livestock - Part 2: Special aspects
IEC 60479-2 describes the effects on the human body when a sinusoidal alternating current in the frequency range above 100 Hz passes through it. The effects of current passing through the human body for: - alternating sinusoidal current with DC components, - alternating sinusoidal current with phase control, and - alternating sinusoidal current with multicycle control are given but are only deemed applicable for alternating current frequencies from 15 Hz up to 100 Hz. Means of extending the frequency of applicability of pure sinusoids to a frequency of 150 kHz are given, supplementing the data in IEC 60479-1. Means of examining random complex irregular waveforms are given. This document describes the effects of current passing through the human body in the form of single and multiple successive unidirectional rectangular impulses, sinusoidal impulses and impulses resulting from capacitor discharges. The values specified are deemed to be applicable for impulse durations from 0,1 ms up to and including 10 ms. This document only considers conducted current resulting from the direct application of a source of current to the body, as does IEC 60479-1. It does not consider current induced within the body caused by its exposure to an external electromagnetic field. This basic safety publication is primarily intended for use by technical committees in the preparation of standards in accordance with the principles laid down in IEC Guide 104 and ISO/IEC Guide 51. It is not intended for use by manufacturers or certification bodies. One of the responsibilities of a technical committee is, wherever applicable, to make use of basic safety publications in the preparation of its publications. The requirements, test methods or test conditions of this basic safety publication will not apply unless specifically referred to or included in the relevant publications.
Vplivi električnega toka na ljudi in živali – 2. del: Posebnosti
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2020
Vplivi električnega toka na ljudi in živali – 2. del: Posebnosti
Effects of current on human beings and livestock - Part 2: Special aspects
Ta slovenski standard je istoveten z:
ICS:
13.200 Preprečevanje nesreč in Accident and disaster control
katastrof
29.020 Elektrotehnika na splošno Electrical engineering in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
IEC 60479-2 ®
Edition 1.0 2019-05
INTERNATIONAL
STANDARD
colour
inside
BASIC SAFETY PUBLICATION
Effects of current on human beings and livestock –
Part 2: Special aspects
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 13.200; 29.020 ISBN 978-2-8322-6689-2
– 2 – IEC 60479-2:2019 © IEC 2019
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Effects of alternating currents with frequencies above 100 Hz . 11
4.1 General . 11
4.2 Effects of alternating current in the frequency range above 100 Hz up to and
including 1 000 Hz . 12
4.2.1 Threshold of perception . 12
4.2.2 Threshold of let-go . 12
4.2.3 Threshold of ventricular fibrillation . 13
4.3 Effects of alternating current in the frequency range above 1 000 Hz up to
and including 10 000 Hz . 14
4.3.1 Threshold of perception . 14
4.3.2 Threshold of let-go . 14
4.3.3 Threshold of ventricular fibrillation . 15
4.4 Effects of alternating current in the frequency range above 10 000 Hz . 15
4.4.1 General . 15
4.4.2 Threshold of perception . 15
4.4.3 Threshold of let-go . 15
4.4.4 Threshold of ventricular fibrillation . 15
4.4.5 Other effects . 16
5 Effects of special waveforms of current . 16
5.1 General . 16
5.2 Equivalent magnitude, frequency and threshold . 16
5.3 Effects of alternating current with DC components . 17
5.3.1 Waveforms and frequencies and current thresholds . 17
5.3.2 Threshold of startle reaction . 18
5.3.3 Threshold of let-go . 19
5.3.4 Threshold of ventricular fibrillation . 20
6 Effects of alternating current with phase control . 24
6.1 Waveforms and frequencies and current thresholds . 24
6.2 Threshold of startle reaction and threshold of let-go . 25
6.3 Threshold of ventricular fibrillation . 25
6.3.1 General . 25
6.3.2 Symmetrical control . 26
6.3.3 Asymmetrical control . 26
7 Effects of alternating current with multicyle control . 26
7.1 Waveforms and frequencies . 26
7.2 Threshold of startle reaction and threshold of let-go . 27
7.3 Threshold of ventricular fibrillation . 27
7.3.1 General . 27
7.3.2 Shock durations longer than 1,5 times the period of the cardiac cycle . 28
7.3.3 Shock durations less than 0,75 times the period of the cardiac cycle . 28
IEC 60479-2:2019 © IEC 2019 – 3 –
8 Estimation of the equivalent current threshold for mixed frequencies . 28
8.1 Threshold of perception and let-go . 28
8.2 Threshold of ventricular fibrillation . 29
9 Effects of current pulse bursts and random complex irregular waveforms . 29
9.1 Ventricular fibrillation threshold of multiple pulses of current separated by
300 ms or more . 29
9.2 Ventricular fibrillation threshold of multiple pulses of current separated by
than 300 ms . 29
less
9.2.1 General . 29
9.2.2 Examples. 30
9.2.3 Random complex irregular waveforms . 32
10 Effects of electric current through the immersed human body . 34
10.1 General . 34
10.2 Resistivity of water solutions and of the human body . 34
10.3 Conducted current through immersed body . 36
10.4 Physiological effects of current through the immersed body . 37
10.5 Threshold values of current . 38
10.6 Intrinsically “safe” voltage values . 38
11 Effects of unidirectional single impulse currents of short duration . 38
11.1 General . 38
11.2 Effects of unidirectional impulse currents of short duration . 39
11.2.1 Waveforms . 39
11.2.2 Determination of specific fibrillating energy F . 40
e
11.3 Threshold of perception and threshold of pain for capacitor discharge . 41
11.4 Threshold of ventricular fibrillation . 43
11.4.1 General . 43
11.4.2 Examples. 44
Annex A (informative) Random complex irregular waveform analysis . 47
A.1 General . 47
A.2 Formal theoretical statement of the method . 47
A.3 Demonstration of the calculation . 48
A.3.1 General . 48
A.3.2 Choice of justified current . 50
A.3.3 Choice of sampling step size . 50
A.4 Examples 1 and 2 . 51
Bibliography . 54
Figure 1 – Variation of the threshold of perception within the frequency range
50/60 Hz to 1 000 Hz . 12
Figure 2 – Variation of the threshold of let-go within the frequency range 50/60 Hz to
1 000 Hz . 13
Figure 3 – Variation of the threshold of ventricular fibrillation within the frequency
range 50/60 Hz to 1 000 Hz, shock durations longer than one heart period and
longitudinal current paths through the trunk of the body . 13
Figure 4 – Variation of the threshold of perception within the frequency range
1 000 Hz to 10 000 Hz . 14
Figure 5 – Variation of the threshold of let-go within the frequency range 1 000 Hz to
10 000 Hz . 14
– 4 – IEC 60479-2:2019 © IEC 2019
Figure 6 – Variation of the threshold of ventricular fibrillation for continuous sinusoidal
current (1 000 Hz to 150 kHz) . 16
Figure 7 – Waveforms of currents . 18
Figure 8 – Let-go thresholds for men, women and children . 19
Figure 9 – 99,5-percentile let-go threshold for combinations of 50/60 Hz sinusoidal
alternating current and direct current . 20
Figure 10 – Composite alternating and direct current with equivalent likelihood of
ventricular fibrillation. 22
Figure 11 – Waveforms of rectified alternating currents . 23
Figure 12 – Waveforms of alternating currents with phase control . 25
Figure 13 – Waveforms of alternating currents calculated with multicycle control factor . 27
Figure 14 – Threshold of ventricular fibrillation (average value) for alternating current
with multicycle control for various degrees of controls (results of experiments with
young pigs) . 28
Figure 15 – Series of four rectangular pulses of unidirectional current . 31
Figure 16 – Series of four rectangular pulses of unidirectional current . 31
Figure 17 – Series of four rectangular pulses of unidirectional current . 32
Figure 18 – Example of current versus elapsed time over a contaminated insulator . 33
Figure 19 – PC plotted on the AC time current curves (IEC 60479-1:2018, Figure 20). 34
Figure 20 – Forms of current for rectangular impulses, sinusoidal impulses and for
capacitor discharges . 40
Figure 21 – Rectangular impulse, sinusoidal impulse and capacitor discharge having
the same specific fibrillating energy and the same shock duration. 41
Figure 22 – Threshold of perception and threshold of pain for the current resulting
from the discharge of a capacitor (dry hands, large contact area) . 42
Figure 23 – Probability of fibrillation risks for current flowing in the path left hand to
feet . 44
Figure A.1 – Definition of a segment of a random complex waveform . 47
Figure A.2 – Definition of a duration within a sample . 47
Figure A.3 – PC for demonstration example of the random complex waveform method
plotted against time-current curves for RMS AC . 50
Figure A.4 – Random complex waveform typical of those used in Example 1 . 51
Figure A.5 – Random complex waveform typical of those used in Example 2 . 52
Figure A.6 – PC for Examples 1 and 2 of the random complex waveform method
plotted against time-current curves for RMS AC . 53
Table 1 – Estimate for ventricular fibrillation threshold after each pulse of current in a
series of pulses each of which excited the heart tissue in such a manner as to trigger
ventricular responses . 30
Table 2 – Resistivity of water solutions [24], [25] . 35
Table 3 – Resistivity of human body tissues . 36
Table 4 – Relative interaction between the resistivity of water solution and the
impedance characteristic of the electrical source . 37
Table 5 – Effects of shocks . 45
Table 6 – Effects of shocks . 46
IEC 60479-2:2019 © IEC 2019 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EFFECTS OF CURRENT ON HUMAN BEINGS AND LIVESTOCK –
Part 2: Special aspects
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,
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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 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
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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.
International Standard IEC 60479-2 has been prepared by IEC technical committee 64:
Electrical installations and protection against electric shock.
This first edition cancels and replaces IEC TS 60479-2:2017. This edition constitutes a
technical revision.
This edition includes the following significant technical changes with respect to
IEC TS 60479-2:2017:
a) change in status from Technical Specification to International Standard.
It has the status of a basic safety publication in accordance with IEC Guide 104.
– 6 – IEC 60479-2:2019 © IEC 2019
The text of this International Standard is based on the following documents:
CDV Report on voting
64/2300/CDV 64/2362/RVC
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 60479 series, published under the general title Effects of current
on human beings and livestock, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
IMPORTANT – The “colour inside” logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this publication using a colour printer.
IEC 60479-2:2019 © IEC 2019 – 7 –
INTRODUCTION
In order to avoid errors in the interpretation of this document, it should be emphasized that
the data given herein is mainly based on experiments with animals as well as on information
available from clinical observations. Only a few experiments with shock currents of short
duration have been carried out on living human beings.
The effects of current passing through the human body for
– alternating sinusoidal current with DC components,
– alternating sinusoidal current with phase control,
– alternating sinusoidal current with multicycle control,
– equivalent current threshold for mixed frequencies,
– current pulse bursts and random complex irregular waveforms,
– electric current through the immersed human body, and
– unidirectional single impulse currents of short duration
are described.
– 8 – IEC 60479-2:2019 © IEC 2019
EFFECTS OF CURRENT ON HUMAN BEINGS AND LIVESTOCK –
Part 2: Special aspects
1 Scope
This part of IEC 60479 describes the effects on the human body when a sinusoidal
alternating current in the frequency range above 100 Hz passes through it.
The effects of current passing through the human body for:
– alternating sinusoidal current with DC components,
– alternating sinusoidal current with phase control, and
– alternating sinusoidal current with multicycle control
are given but are only deemed applicable for alternating current frequencies
from 15 Hz up to 100 Hz.
Means of extending the frequency of applicability of pure sinusoids to a frequency of 150 kHz
are given, supplementing the data in IEC 60479-1.
Means of examining random complex irregular waveforms are given.
This document describes the effects of current passing through the human body in the form of
single and multiple successive unidirectional rectangular impulses, sinusoidal impulses and
impulses resulting from capacitor discharges.
The values specified are deemed to be applicable for impulse durations from 0,1 ms up to and
including 10 ms.
This document only considers conducted current resulting from the direct application of a
source of current to the body, as does IEC 60479-1. It does not consider current induced
within the body caused by its exposure to an external electromagnetic field.
This basic safety publication is primarily intended for use by technical committees in the
preparation of standards in accordance with the principles laid down in IEC Guide 104 and
ISO/IEC Guide 51. It is not intended for use by manufacturers or certification bodies.
One of the responsibilities of a technical committee is, wherever applicable, to make use of
basic safety publications in the preparation of its publications. The requirements, test
methods or test conditions of this basic safety publication will not apply unless specifically
referred to or included in the relevant publications.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their
content constitutes requirements 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 60479-1:2018, Effects of current on human beings and livestock – Part 1: General
aspects
IEC 60479-2:2019 © IEC 2019 – 9 –
IEC 60990, Methods of measurement of touch-current and protective conductor current
IEC Guide 104, The preparation of safety publications and the use of basic safety publications
and group safety publications
ISO/IEC Guide 51, Safety aspects – Guidelines for their inclusion in standards
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60479-1 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
frequency factor
F
f
ratio of the threshold current for the relevant physiological effects at the frequency f to the
threshold current at 50/60 Hz.
Note 1 to entry: The frequency factor differs for perception, let-go and ventricular fibrillation.
3.2
phase control
process of varying the instant within the cycle at which current conduction in an electronic
valve device or a valve arm begins
[SOURCE: IEC 60050-551:1998, 551-16-23]
3.3
phase control angle
current delay angle
time expressed in angular measure by which the starting instant of current conduction is
delayed by phase control
[SOURCE: IEC 60050-551:1998, 551-16-32, modified — The term "phase control angle" has
been added.]
3.4
multicycle control
process of varying the ratio of the number of cycles which include current conduction to the
number of cycles in which no current conduction occurs
[SOURCE: IEC 60050-551:1998, 551-16-31]
3.5
multicycle control factor
p
ratio between the number of conducting cycles and the sum of conducting and non-conducting
cycles in the case of multicycle control
SEE Figure 13.
– 10 – IEC 60479-2:2019 © IEC 2019
[SOURCE: IEC 60050-551:1998, 551-16-37, modified — The symbol and reference to
Figure 13 have been added.]
3.6
specific fibrillating energy
F
e
·t value of a unidirectional impulse of short duration which under given conditions
minimum I
(current-path, heart-phase) causes ventricular fibrillation with a certain probability
Note 1 to entry: F is determined by the form of the impulse as the integral
e
t
i 2
i dt
∫
where t is defined in Figure 20 and Figure 21. F multiplied by the body resistance gives the energy dissipated in
i e
the human body during the impulse.
Note 2 to entry: F is expressed in Ws/Ω or A s.
e
3.7
specific fibrillating charge
F
q
minimum I·t value of unidirectional impulse of short duration which under given conditions
(current-path, heart-phase) causes ventricular fibrillation with a certain probability
Note 1 to entry: F is determined by the form of the impulse as the integral
q
t
i
idt
∫
where t is defined in Figure 20 and Figure 21.
i
Note 2 to entry: F is expressed in C or As.
q
3.8
time constant
time required for the amplitude of an exponentially decaying quantity to decrease to
= 0,367 9
e
times an initial amplitude
[SOURCE: IEC 60050-801:1994, 801-21-45, modified — The definition has been revised.]
3.9
shock duration
t
i
time interval from the beginning of the discharge to the time when
the discharge current has fallen to 5 % of its peak value
Note 1 to entry: When the time constant of the capacitor discharge is given by T the shock duration of the
capacitor discharge is equal to 3T. During the shock duration of the capacitor discharge practically all the energy of
the impulse is dissipated.
Note 2 to entry: See Figure 20 and Figure 21.
3.10
shock duration
t
i
shortest duration of that part of the impulse that contains
95 % of the energy over the total impulse
IEC 60479-2:2019 © IEC 2019 – 11 –
3.11
threshold of perception
minimum value for the charge of electricity, which, under given conditions, causes any
sensation to the person through whom it is flowing
3.12
threshold of pain
2⋅
minimum value for the charge (I∙t) or specific energy (I t) that can be applied as an impulse
to a person holding a large electrode in the hand without causing pain
3.13
pain
unpleasant experience such that it is not readily accepted a second time by the subject
submitted to it
EXAMPLE: Electric shock above the threshold of pain described in 11.3, the sting of a bee or the burn of a
cigarette.
4 Effects of alternating currents with frequencies above 100 Hz
NOTE Values for 50/60 Hz are given in IEC 60479-1. For frequencies up to 100 Hz the provisions of IEC 60479-1
are used.
4.1 General
Electric energy in the form of alternating current at frequencies higher than 50/60 Hz is
increasingly used in modern electrical equipment, for example aircraft (400 Hz), power tools
and electric welding (mostly up to 450 Hz), electrotherapy (using mostly 4 000 Hz to
5 000 Hz) and switching mode power supplies (20 kHz to 1 MHz).
Little experimental data is available for Clause 4, therefore the information given herein
should be considered as provisional only but may be used for the evaluation of risks in the
frequency ranges concerned (see Bibliography).
Recent experiments in government-funded projects are ongoing to exploit and investigate the
effects of higher frequencies using the latest technologies and methods to justify existing
extrapolation of the frequency factor for ventricular fibrillation (VF) threshold.
Attention is also drawn to the fact that the impedance of human skin decreases
approximately inversely proportional to the frequency for touch voltages in the order of
some tens of volts, so that the skin impedance at 500 Hz is only about one-tenth of the skin
impedance at 50 Hz and may be neglected in many cases. This impedance of the human
body at such frequencies is therefore reduced to its internal impedance Z (see
i
IEC 60479-1).
NOTE Use of peak measurements: at current levels that produce physiological responses of perception,
startle reaction and inability of let-go, the physiological response from non-sinusoidal and mixed-frequency
periodic current is best indicated by the peak value of an output signal from measuring circuits containing a
frequency-weighting network such as those described in IEC 60990.
These frequency-weighting networks attenuate the signal according to the frequency factors
given in IEC 60479-1:2018, Clause 4 so that the output signal corresponds to a constant
level of physiological response. Attenuation is provided for narrow impulses of current that
would produce less physiological response because of the short duration of their peak value.
The network output allows a fixed value to be read independently of waveshape or mix of
frequencies to be provided for ease of determination of the leakage current and evaluation of
the level of hazard present.
Comparable physiological effects are produced by non-sinusoidal and sinusoidal currents
producing the same peak values by this measurement method.
– 12 – IEC 60479-2:2019 © IEC 2019
A representative network can be found in IEC 60990 and in [16] .
4.2 Effects of alternating current in the frequency range above 100 Hz up to and
including 1 000 Hz
4.2.1 Threshold of perception
For the threshold of perception, the frequency factor is given in Figure 1.
Figure 1 – Variation of the threshold of perception
within the frequency range 50/60 Hz to 1 000 Hz
4.2.2 Threshold of let-go
For the threshold of let-go, the frequency factor is given in Figure 2.
___________
Numbers in square brackets refer to the Bibliography.
IEC 60479-2:2019 © IEC 2019 – 13 –
Figure 2 – Variation of the threshold of let-go
within the frequency range 50/60 Hz to 1 000 Hz
4.2.3 Threshold of ventricular fibrillation
For shock durations longer than the cardiac cycle, the frequency factor for the threshold of
fibrillation for longitudinal current paths through the trunk of the body is given in Figure 3.
For shock durations shorter than the cardiac cycle, no experimental data is available on the
effects of frequency.
Figure 3 – Variation of the threshold of ventricular fibrillation within the frequency
range 50/60 Hz to 1 000 Hz, shock durations longer than one heart period and
longitudinal current paths through the trunk of the body
– 14 – IEC 60479-2:2019 © IEC 2019
4.3 Effects of alternating current in the frequency range above 1 000 Hz up to and
including 10 000 Hz
4.3.1 Threshold of perception
For the threshold of perception, the frequency factor is given in Figure 4.
Figure 4 – Variation of the threshold of perception
within the frequency range 1 000 Hz to 10 000 Hz
4.3.2 Threshold of let-go
For the threshold of let-go, the frequency factor is given in Figure 5.
Figure 5 – Variation of the threshold of let-go
within the frequency range 1 000 Hz to 10 000 Hz
IEC 60479-2:2019 © IEC 2019 – 15 –
4.3.3 Threshold of ventricular fibrillation
For frequencies between 1 000 Hz and 10 000 Hz, the provisions of 4.4.4 are used.
4.4 Effects of alternating current in the frequency range above 10 000 Hz
4.4.1 General
In 4.4, changes have not been made to the values of the threshold of perception, or the
threshold of let-go for higher frequencies. While these are important thresholds, the most
dangerous is that of ventricular fibrillation. The fibrillation threshold is therefore given up to
150 kHz. The remaining thresholds may be considered as in the paragraphs below up to the
frequency limits shown.
4.4.2 Threshold of perception
For frequencies between 10 kHz and 100 kHz, the threshold rises approximately from 10 mA
to 100 mA (RMS values).
For frequencies above 100 kHz, the tingling sensation characteristic for the perception at
lower frequencies changes into a sensation of warmth for current intensities in the order of
some hundred mill amperes.
4.4.3 Threshold of let-go
For frequencies above 100 kHz, there is neither experimental data nor reported incidents
concerning the threshold of let-go.
4.4.4 Threshold of ventricular fibrillation
For shock durations longer than the cardiac cycle, the frequency factor for the threshold of
fibrillation for longitudinal current paths through the trunk of the body for the frequency range
above 1 000 Hz up to and including 150 kHz is given in Figure 6.
For frequencies above 1 kHz, thermal effects are more likely to become dominant.
For shock durations shorter than the cardiac cycle, no experimental data is available.
– 16 – IEC 60479-2:2019 © IEC 2019
Figure 6 – Variation of the threshold of ventricular fibrillation for
continuous sinusoidal current (1 000 Hz to 150 kHz)
4.4.5 Other effects
Burns may occur at frequencies above 100 kHz and current magnitudes in the order of
amperes depending on the duration of the current flow.
5 Effects of special waveforms of current
5.1 General
As is to be expected, the effects of such currents on the human body are between those
caused by direct and by alternating current; therefore, equivalent current magnitudes with
regard to ventricular fibrillation can be established.
Clause 5 describes the effects of current passing through the human body for:
– alternating sinusoidal current with DC components,
– alternating sinusoidal current with phase control,
– alternating sinusoidal current with multicycle control.
NOTE Other waveforms are under consideration.
The information given is deemed applicable for alternating current frequencies from 15 Hz up
to 100 Hz.
5.2 Equivalent magnitude, frequency and threshold
In 5.2, the hazard may be taken as having approximately the same effect as with an
equivalent pure alternating sinusoidal current I having the following characteristics:
ev
– Magnitude equivalence:
The following current magnitudes have to be distinguished:
I = RMS value of the current of the proposed waveform,
RMS
IEC 60479-2:2019 © IEC 2019 – 17 –
I = peak value of the current of the proposed waveform,
p
I = peak-to-peak value of the current of the proposed waveform,
pp
I = RMS value of a sinusoidal current presenting the same effect as
ev
the waveform concerned.
NOTE The current I is used instead of the current I given in IEC 60479-1:2018, Figure 20 and Figure 22 to
ev B
estimate the risk of ventricular fibrillation.
Most physiological effects are related to the filtered peak current (in magnitude and in
duration) with the natural body filter defined by the frequency factor F. The peak value of
the current should be used in all cases except where there is a known relationship
between the RMS value and the peak value, i.e. pure sinusoidal current.
– Frequency equivalence
The waveform under study has a time period equal to the period of the equivalent
sinusoidal waveform.
– Threshold equivalence
The different current thresholds (perception, inability of let-go and ventricular fibrillation)
for waveforms consisting of specific ratios of alternating to direct current are equivalent to
a pure sinusoidal alternating current with a current having the characteristic equal to I .
ev
This I value is different for each of these thresholds.
ev
5.3 Effects of alternating current with DC components
5.3.1 Waveforms and frequencies and current thresholds
Figure 7 shows typical waveforms, which are dealt with in 5.3.1. Pure DC and pure AC are
represented as well as combined waveforms of various AC to DC ratios.
– 18 – IEC 60479-2:2019 © IEC 2019
a) Combined waveforms of various AC to DC ratios together with rectangle pulse
for shock duration >1,5 and <0,75 of the cardiac cycle
b) Combined waveforms of various AC to DC ratios of mixed frequencies
for shock duration >1,5 and <0,75 of the cardiac cycle
Figure 7 – Waveforms of currents
5.3.2 Threshold of startle reaction
The threshold of startle reaction depends on several parameters such as the area of the body
in contact with an electrode (contact area), the conditions of contact (dry, wet, pressure,
temperature), and also on the physiological characteristics of the individual.
These effects are related to the peak value of the current [13] and the currents have to be
combined frequency by frequency to estimate the total effect. A measurement circuit is
described in IEC 60990.
IEC 60479-2:2019 © IEC 2019 – 19 –
5.3.3 Threshold of let-go
The threshold of let-go depends on several parameters, such as the contact area, the shape
and the size of the electrodes, and also on the physiological characteristics of the individual.
From the standpoint of let-go (hand contacts with energized circuitry that can last a few
seconds), this document uses Figure 5 in the referenced Dalziel paper [17] to determine the
let-go current threshold for combinations of alternating current and direct current. The
frequency of the alternating current in this case was 60 Hz. A value of 7,07 mA peak AC
(5 mA RMS for a sinusoidal current) and 30 mA DC were used as the touch current thresholds
for pure AC and DC respectively. These thresholds are considered to be adequate to
represent the entire population (including children) from inability to let go.
The equation, I = 7,176 × exp (−0,143 4 × DC) − 0,106 1, represents this combined AC
AC peak
and DC case and may be used to calculate the result of any combination of AC and DC in the
range specified.
The following Figure 8 illustrates the information given by Dalziel.
Figure 8 – Let-go thresholds for men, women and children
The above curves can be described by an equation fitted to the data.
The equation, I = 12,890 5 × exp (−0,069 39 × DC) − 0,190 5, represents the 99,5-
AC peak
percentile curve for men.
The equation, I = 8,523 × exp (−0,104 9 × DC) − 0,126, represents the 99,5-percentile
AC peak
curve for women.
The equation, I = 6,394 5 × exp (−0,138 8 × DC) − 0,094 5, represents the 99,5-
AC peak
percentile estimated curve for children.
For practical considerations, some standards allow for some ripple (e.g. up to 10 %) on a DC
supply as an exception.
Figure 9 shows the let-go threshold expressed in peak mA for combinations of 50/60 Hz
sinusoidal alternating current and direct current. The peak of the composite AC and DC wave
– 20 – IEC 60479-2:2019 © IEC 2019
in mA at the let-go threshold estimated for the population of humans, including children, is
shown as a function of the direct current component in mA.
Figure 9 is represented by the equation for the composite current:
I + I = 7,176 × exp (−0,143 4 × DC) − 0,106 1 + DC
AC peak DC
Figure 9 – 99,5-percentile let-go threshold for combinations
of 50/60 Hz sinusoidal alternating current and direct current
These effects are related to the peak value of the current [6] and the currents have to be
combined frequency by frequency to estimate the total effect. A measurement circuit is
described in IEC 60990.
5.3.4 Threshold of ventricular fibrillation
5.3.4.1 Waveforms consisting of specific ratios of alternating to direct current
The fibrillation hazard may be taken as being approximately the same as with an equivalent
alternating sinusoidal current I having the following characteristics:
ev
a) For shock durations longer than approximately 1,5 times the period of the cardiac cycle,
I is the RMS value of the sinusoidal alternating current having the same peak-to peak
ev
value I as the current of the waveform concerned.
pp
I
pp
I =
ev
b) For shock durations shorter than approximately 0,75 times the period of the cardiac cycle,
I is the RMS value of the sinusoidal alternating current having the same peak value I as
ev p
the current of the waveform concerned.
I
p
I =
ev
IEC 60479-2:2019 © IEC 2019 – 21 –
NOTE 1 This correlation is less applicable the smaller the ratio AC to DC becomes. For pure DC shocks of a
duration of less than 0,1 s, the threshold is equal to the corresponding RMS value of the alternating current
(see IEC 60479-1:2018, Figure 20 or Figure 22).
c) In the duration range from 0,75 to 1,5 times the period of the cardiac cycle, the amplitude
parameter changes from peak value to peak-to-peak value.
NOTE 2 The details of the nature of the transition that takes place are subject to further studies.
Accord
...
SL O V EN S K I SIST IEC 60479-2
S T ANDAR D junij 2020
Vplivi električnega toka na ljudi in živali – 2. del: Posebnosti
Effects of current on human beings and livestock – Part 2: Special aspects
Referenčna oznaka
ICS 13.200; 29.020 SIST IEC 60479-2:2020 (sl)
Nadaljevanje na straneh 2 do 53
© 2023-10. Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno.
SIST IEC 60479-2 : 2020
NACIONALNI UVOD
Standard SIST IEC 60479-2 (sl), Vplivi električnega toka na ljudi in živali – 2. del: Posebnosti, 2020, ima
status slovenskega standarda in je istoveten mednarodnemu standardu IEC 60479-2 (en), Effects of
current on human beings and livestock – Part 2: Special aspects, 2019.
NACIONALNI PREDGOVOR
Mednarodni standard IEC 60479-2:2019 je pripravil tehnični odbor IEC/TC 64 Električne inštalacije in
zaščita pred električnim šokom.
Slovenski standard SIST IEC 60479-2:2020 je prevod mednarodnega standarda IEC 60479-2:2019. V
primeru spora glede besedila slovenskega prevoda v tem standardu je odločilen izvirni mednarodni
standard v angleškem jeziku. Slovensko izdajo standarda je potrdil tehnični odbor SIST/TC ELI
Nizkonapetostne in komunikacijske električne inštalacije.
Odločitev za privzem tega standarda je junija 2020 sprejel tehnični odbor SIST/TC ELI Nizkonapetostne
in komunikacijske električne inštalacije.
ZVEZA Z NACIONALNIMI STANDARDI
S privzemom tega evropskega standarda veljajo za omejeni namen referenčnih standardov vsi
standardi, navedeni v izvirniku, razen tistih, ki so že sprejeti v nacionalno standardizacijo:
SIST IEC 60479-1:2020 Vplivi električnega toka na ljudi in živali – 1. del: Splošno
SIST EN 60990 Metode merjenja toka dotika in toka v zaščitnem vodniku
OSNOVA ZA IZDAJO STANDARDA
– privzem standarda IEC 60479-2:2019
OPOMBI
– Povsod, kjer se v besedilu standarda uporablja izraz “mednarodni standard”, v SIST IEC 60479-
2:2020 to pomeni “slovenski standard”.
– Nacionalni uvod in nacionalni predgovor nista sestavna dela standarda.
SIST IEC 60479-2 : 2020
VSEBINA Stran
Predgovor . 6
Uvod . 8
1 Področje uporabe . 9
2 Zveze s standardi . 9
3 Izrazi in definicije .10
4 Učinki izmeničnih tokov s frekvencami nad 100 Hz .12
4.1 Splošno .12
4.2 Učinki izmeničnega toka v frekvenčnem območju nad 100 Hz in do vključno 1 000 Hz .12
4.2.1 Prag zaznavanja .12
4.2.2 Prag sprostitve .13
4.2.3 Prag ventrikularne fibrilacije .14
4.3 Učinki izmeničnega toka v frekvenčnem območju nad 1 000 Hz in do vključno 10 000 Hz .14
4.3.1 Prag zaznavanja .14
4.3.2 Prag sprostitve .15
4.3.3 Prag ventrikularne fibrilacije .16
4.4 Učinki izmeničnega toka v frekvenčnem območju nad 10 000 Hz .16
4.4.1 Splošno .16
4.4.2 Prag zaznavanja .16
4.4.3 Prag sprostitve .16
4.4.4 Prag ventrikularne fibrilacije .16
4.4.5 Drugi učinki .17
5 Učinki posebnih valovnih oblik toka .17
5.1 Splošno .17
5.2 Enakovrednost velikosti, frekvence in praga .17
5.3 Učinki izmeničnega toka z enosmernimi komponentami .18
5.3.1 Valovne oblike in frekvence ter tokovni pragi .18
5.3.2 Prag odziva na strah.19
5.3.3 Prag sprostitve .19
5.3.4 Prag ventrikularne fibrilacije .20
6 Učinki izmeničnega toka s faznim krmiljenjem .23
6.1 Valovne oblike in frekvence ter tokovni pragi .23
6.2 Prag odziva na strah in prag sprostitve .24
6.3 Prag ventrikularne fibrilacije .25
6.3.1 Splošno .25
6.3.2 Simetrično krmiljenje .25
6.3.3 Nesimetrično krmiljenje .25
7 Učinki izmeničnega toka z večperiodnim krmiljenjem .26
7.1 Valovne oblike in frekvence .26
7.2 Prag odziva na strah in prag sprostitve .26
7.3 Prag ventrikularne fibrilacije .26
SIST IEC 60479-2 : 2020
7.3.1 Splošno .26
7.3.2 Trajanja udara, daljša od 1,5-kratne periode srčnega cikla .27
7.3.3 Trajanja udara, krajša od 0,75-kratne periode srčnega cikla .27
8 Ocena enakovrednosti tokovnega praga za mešane frekvence .27
8.1 Prag zaznavanja in sprostitve .27
8.2 Prag ventrikularne fibrilacije .28
9 Učinki rafalov udarov toka in naključnih zapletenih nepravilnih valovnih oblik .28
9.1 Prag ventrikularne fibrilacije pri večkratnih udarih toka, medsebojno ločenih za 300 ms
ali več .28
9.2 Prag ventrikularne fibrilacije pri večkratnih udarih toka, medsebojno ločenih za manj
kot 300 ms .28
9.2.1 Splošno .28
9.2.2 Primeri .29
9.2.3 Naključne zapletene nepravilne valovne oblike .31
10 Učinki električnega toka skozi potopljeno človeško telo .33
10.1 Splošno .33
10.2 Specifična upornost vodnih raztopin in človeškega telesa .33
10.3 Prevajani tok skozi potopljeno telo .35
10.4 Fiziološki učinki toka skozi potopljeno telo .35
10.5 Vrednosti tokovnih pragov .36
10.6 "Lastnovarne" vrednosti napetosti .36
11 Učinki kratkotrajnih posameznih udarov enosmernega toka .37
11.1 Splošno .37
11.2 Učinki kratkotrajnih udarov enosmernega toka .37
11.2.1 Valovne oblike .37
11.2.2 Ugotavljanje specifične fibrilacijske energije F .38
e
11.3 Prag zaznavanja in prag bolečine za praznjenje kondenzatorja .39
11.4 Prag ventrikularne fibrilacije .41
11.4.1 Splošno .41
11.4.2 Primeri .42
Dodatek A (informativni): Analiza naključne zapletene nepravilne valovne oblike .44
A.1 Splošno .44
A.2 Formalna teoretična izjava metode .44
A.3 Prikaz izračuna .45
A.3.1 Splošno .45
A.3.2 Izbira nastavljenega toka .47
A.3.3 Izbira velikosti koraka vzorčenja .47
A.4 Primera 1 in 2 .48
Literatura.51
Slika 1: Spreminjanje praga zaznavanja v frekvenčnem območju 50/60 Hz do 1 000 Hz .13
Slika 2: Spreminjanje praga sprostitve v frekvenčnem območju 50/60 Hz do 1 000 Hz .13
SIST IEC 60479-2 : 2020
Slika 3: Spreminjanje praga ventrikularne fibrilacije v frekvenčnem območju 50/60 Hz do 1 000 Hz
pri trajanju udarov, daljšem od enega srčnega cikla, in vzdolžnih poti toka skozi trup telesa .14
Slika 4: Spreminjanje praga zaznavanja v frekvenčnem območju 1 000 Hz do 10 000 Hz .15
Slika 5: Spreminjanje praga sprostitve v frekvenčnem območju 1 000 Hz do 10 000 Hz .15
Slika 6: Spreminjanje praga ventrikularne fibrilacije pri stalnem sinusnem toku
(1 000 Hz do 150 kHz) .16
Slika 7: Valovne oblike tokov .18
Slika 8: Pragi sprostitve za moške, ženske in otroke .19
Slika 9: 99,5-odstotni prag sprostitve za kombinacije sinusnega izmeničnega toka 50/60 Hz
in enosmernega toka .20
Slika 10: Sestavljen izmenični in enosmerni tok z enako verjetnostjo nastanka
ventrikularne fibrilacije .21
Slika 11: Valovne oblike usmerjenih izmeničnih tokov .22
Slika 12: Valovne oblike izmeničnih tokov s faznim krmiljenjem .24
Slika 13: Valovne oblike izmeničnih tokov, izračunanih s faktorjem večperiodnega krmiljenja .26
Slika 14: Prag ventrikularne fibrilacije (povprečna vrednost) za izmenični tok z večperiodnim
krmiljenjem za različne kote krmiljenja (rezultati poskusov z mladimi prašiči) .27
Slika 15: Serija štirih pravokotnih udarov enosmernega toka .29
Slika 16: Serija štirih pravokotnih udarov enosmernega toka .30
Slika 17: Serija štirih pravokotnih udarov enosmernega toka .31
Slika 18: Primer časovne odvisnosti toka čez kontaminiran izolator .32
Slika 19: PC, prikazan na krivuljah čas-tok izmeničnega toka (IEC 60479-1:2018, slika 20) .33
Slika 20: Oblike tokov za pravokotne udare, sinusne udare in toke pri razelektritvi kondenzatorja .38
Slika 21: Pravokotni udar, sinusni udar in praznjenje kondenzatorja imajo isto
specifično fibrilacijsko energijo in isto trajanje udara .39
Slika 22: Prag zaznavanja in prag bolečine za tok, ki je posledica praznjenja kondenzatorja
(suhi roki, obsežna stična površina) .40
Slika 23: Verjetnost tveganja fibrilacije za tok, ki teče po poti leva roka–stopala .41
Slika A.1: Definicija odseka naključne zapletene valovne oblike .44
Slika A.2: Definicija trajanja znotraj vzorca .44
Slika A.3: PC za prikaz primera metode za naključno zapleteno valovno obliko, narisano glede na
krivulje čas-tok za efektivno vrednost izmeničnega toka .47
Slika A.4: Tipična naključna zapletena valovna oblika, ena od uporabljenih v primeru 1 .48
Slika A.5: Tipična naključna zapletena valovna oblika, ena od uporabljenih v primeru 2 .49
Slika A.6: PC za primera 1 in 2 metode z naključno zapleteno valovno obliko,
narisan glede na krivulje čas-tok za efektivno vrednost izmeničnega toka .50
Preglednica 1: Ocena praga ventrikularne fibrilacije po vsakem udaru toka v seriji udarov,
od katerih vsak tako vzbudi srčno tkivo, da sproži ventrikularne odzive .29
Preglednica 2: Specifična upornost vodnih raztopin [24], [25] .34
Preglednica 3: Specifična upornost tkiv človeškega telesa .34
Preglednica 4: Relativni medsebojni vpliv med specifično upornostjo vodne raztopine in
karakteristikami impedance električnega vira .35
Preglednica 5: Učinki udarov .42
Preglednica 6 – Učinki udarov .43
SIST IEC 60479-2 : 2020
MEDNARODNA ELEKTROTEHNIŠKA KOMISIJA
VPLIVI TOKA NA LJUDI IN ŽIVALI –
2. del: Posebnosti
Predgovor
1. Mednarodna elektrotehniška komisija (IEC) je svetovna organizacija za standardizacijo, ki združuje vse nacionalne
elektrotehnične komiteje (nacionalni komiteji IEC). Cilj IEC je pospeševati mednarodno sodelovanje v vseh vprašanjih
standardizacije s področja elektrotehnike in elektronike. V ta namen poleg drugih aktivnosti izdaja mednarodne standarde,
tehnične specifikacije, tehnična poročila, javno dostopne specifikacije (PAS) in vodila (v nadaljevanju: publikacije IEC). Za
njihovo pripravo so odgovorni tehnični odbori; vsak nacionalni komite IEC, ki ga zanima obravnavana tema, lahko sodeluje
v tem pripravljalnem delu. Prav tako lahko v pripravi sodelujejo mednarodne organizacije ter vladne in nevladne ustanove,
ki so povezane z IEC. IEC deluje v tesni povezavi z mednarodno organizacijo za standardizacijo ISO skladno s pogoji,
določenimi v soglasju med obema organizacijama.
2. Uradne odločitve ali sporazumi IEC o tehničnih vprašanjih, pripravljeni v tehničnih odborih, kjer so prisotni vsi nacionalni
komiteji, ki jih tema zanima, izražajo, kolikor je mogoče, mednarodno soglasje o obravnavani temi.
3. Publikacije IEC imajo obliko priporočil za mednarodno uporabo ter jih kot takšne sprejmejo nacionalni komiteji IEC. Čeprav
IEC skuša zagotavljati natančnost tehničnih vsebin v publikacijah IEC, IEC ni odgovoren za način uporabe ali za možne
napačne interpretacije končnih uporabnikov.
4. Da bi se pospeševalo mednarodno poenotenje, so nacionalni komiteji IEC v svojih nacionalnih in regionalnih standardih
dolžni čim pregledneje uporabljati mednarodne standarde. Vsako odstopanje med standardom IEC in ustreznim
nacionalnim ali regionalnim standardom je treba v slednjem jasno označiti.
5. IEC sam ne izvaja potrjevanja skladnosti. Storitve ugotavljanja skladnosti in na nekaterih območjih tudi dostop do znakov
skladnosti IEC izvajajo neodvisni certifikacijski organi. IEC ni določil nobenega postopka v zvezi z označevanjem kot znakom
strinjanja in ne prevzema nikakršne odgovornosti za storitve, ki jih izvajajo neodvisni certifikacijski organi.
6. Vsi uporabniki naj bi si zagotovili zadnjo izdajo teh publikacij.
7. IEC ali njegovi direktorji, zaposleni, uslužbenci ali agenti, vključno s samostojnimi strokovnjaki ter člani tehničnih odborov in
nacionalnih komitejev IEC, ne prevzemajo nobene odgovornosti za kakršnokoli osebno poškodbo, škodo na premoženju ali
katerokoli drugo škodo kakršnekoli vrste, bodisi posredne ali neposredne, ali za stroške (vključno z zakonitim lastništvom)
in izdatke, povezane s publikacijo, njeno uporabo ali zanašanjem na to publikacijo IEC ali katerokoli drugo publikacijo IEC.
8. Posebno pozornost je treba posvetiti normativnim virom, na katere se sklicuje ta publikacija. Uporaba navedenih publikacij
je nujna za pravilno uporabo te publikacije.
9. Opozoriti je treba na možnost, da bi lahko bil kateri od elementov tega mednarodnega standarda predmet patentnih pravic.
IEC ne odgovarja za identifikacijo nobene od teh patentnih pravic.
Mednarodni standard IEC 60479-2 je pripravil tehnični odbor IEC/TC 64 Električne inštalacije in zaščita
pred električnim udarom.
Ta prva izdaja razveljavlja in nadomešča IEC/TS 60479-2:2017. Ta izdaja predstavlja tehnično
spremembo.
Ta izdaja vključuje naslednje pomembne tehnične spremembe glede na IEC/TS 60479-2:2017:
a) spremenjen je status iz tehnične specifikacije v mednarodni standard.
Dokument ima status osnovne varnostne publikacije v skladu z IEC Vodilom 104.
SIST IEC 60479-2 : 2020
Besedilo tega mednarodnega standarda temelji na naslednjih dokumentih:
CDV Poročilo o glasovanju
64/2300/CDV 64/2362/RVC
Vse informacije o glasovanju za potrditev tega mednarodnega standarda so v poročilu o glasovanju,
navedenem v gornji preglednici.
Ta dokument je bil pripravljen v skladu z 2. delom Direktiv ISO/IEC.
Seznam vseh delov v skupini IEC 60479, objavljen pod splošnim naslovom Vplivi električnega toka na
ljudi in živali, je na voljo na spletnih straneh IEC.
Tehnični odbor je sklenil, da bo vsebina tega standarda ostala nespremenjena do datuma stabilnosti, ki
je določen na spletni strani IEC "http://webstore.iec.ch" pri podatkih za to publikacijo. Po tem datumu bo
dokument:
– ponovno potrjen,
– razveljavljen,
– zamenjan z novo izdajo ali
– dopolnjen.
Dvojezična različica te publikacije je lahko izdana pozneje.
POMEMBNO: Logotip "v barvah" na platnicah te publikacije opozarja, da vsebuje barve, ki so potrebne
za pravilno razumevanje njene vsebine. Uporabniki naj zato tiskajo ta dokument z barvnim tiskalnikom.
SIST IEC 60479-2 : 2020
Uvod
Da bi se izognili napačnim interpretacijam tega dokumenta, je treba poudariti, da so podatki v njem
pridobljeni večinoma s poskusi na živalih in z razpoložljivimi informacijami iz kliničnih opazovanj. Le
nekaj preskusov udarov s kratkotrajnimi toki je bilo izvedenih na živih ljudeh.
Opisani so učinki toka, ki teče skozi človeško telo, za:
– sinusni izmenični tok z enosmernimi komponentami,
– sinusni izmenični tok s faznim krmiljenjem,
– sinusni izmenični tok z večperiodnim krmiljenjem,
– enakovrednost tokovnih pragov za mešane frekvence,
– rafale udarov toka in zapletene nepravilne valovne oblike,
– električni tok skozi potopljeno človeško telo in
– kratkotrajne posamezne udare enosmernega toka.
SIST IEC 60479-2 : 2020
Učinki toka na ljudi in živali – 2. del: Posebnosti
1 Področje uporabe
Ta del IEC 60479 opisuje učinke na človekovo telo, ko skozenj teče sinusni izmenični tok v frekvenčnem
območju nad 100 Hz.
Podani so učinki toka, ki teče skozi človeško telo, za:
– sinusni izmenični tok z enosmernimi komponentami,
– sinusni izmenični tok s faznim krmiljenjem in
– sinusni izmenični tok z večperiodnim krmiljenjem,
vendar se štejejo, da so uporabni le za izmenični tok s frekvenco od 15 Hz do 100 Hz.
Podani so načini za širitev uporabne frekvence čistih sinusoid do frekvence 150 kHz, s čimer
dopolnjujejo podatke v IEC 60479-1.
Podani so načini za preverjanje zapletenih nepravilnih oblik.
Ta dokument opisuje učinke toka, ki teče skozi človeško telo v obliki enega ali več zaporednih
pravokotnih udarov enosmernega toka, sinusnih udarov in udarov, ki so posledica razelektritev
kondenzatorja.
Šteje se, da so podane vrednosti uporabne za dolžine udarov od 0,1 ms do vključno 10 ms.
Ta dokument upošteva samo prevajani tok, ki je posledica neposrednega priklopa tokovnega vira na
telo, kot je pri IEC 60479-1. Ne upošteva toka, ki se inducira v telesu zaradi njegove izpostavljenosti
zunanjemu elektromagnetnemu polju.
Ta osnovna varnostna publikacije je primarno namenjena tehničnim odborom za pripravo standardov
skladno z načeli, podanimi v IEC Vodilu 104 in lSO/lEC Vodilu 51. Ni namenjena, da bi jo uporabljali
proizvajalci ali certifikacijski organi.
Ena od odgovornosti tehničnega odbora je, kjerkoli je uporabno, zagotoviti uporabo osnovne varnostne
publikacije pri pripravi svojih publikacij. Zahteve, preskusne metode ali preskusni pogoji te osnovne
varnostne publikacije veljajo samo, če so izrecno navedeni ali so vključeni v ustrezne publikacije.
2 Zveze s standardi
Za uporabo tega standarda so, delno ali v celoti, nujno potrebni spodaj navedeni referenčni dokumenti.
Pri datiranih sklicevanjih se uporablja le navedena izdaja. Pri nedatiranih sklicevanjih se uporablja
zadnja izdaja publikacije (vključno z dopolnili).
IEC 60479-1:2018 Učinki toka na ljudi in živali – 1. del: Splošni vidiki
IEC 60990 Metode merjenja toka dotika in toka zaščitnega vodnika
IEC Vodilo 104 Priprava varnostnih publikacij in uporaba osnovnih varnostnih publikacij in
publikacij o skupinski varnosti
ISO/IEC Vodilo 51 Varnostni vidiki – Smernice za njihovo vključitev v standarde
SIST IEC 60479-2 : 2020
3 Izrazi in definicije
V tem dokumentu se uporabljajo naslednji izrazi in definicije iz IEC 60479-1, ter tudi naslednji.
ISO in IEC hranita terminološke zbirke podatkov za uporabo v standardizaciji na naslednjih naslovih:
– IEC Electropedia: na voljo na spletnem mestu http://www.electropedia.org/
– platforma za brskanje po spletu ISO: na voljo na spletnem mestu http://www.iso.org/obp
3.1
faktor frekvence
F
f
razmerje med tokovnim pragom za ustrezne fiziološke učinke pri frekvenci f in tokovnim pragom pri
50/60 Hz
OPOMBA: Faktor frekvence je različen za zaznavanje, sprostitev in ventrikularno fibrilacijo.
3.2
fazno krmiljenje
proces spreminjanja trenutka v ciklu, pri katerem se začne prevajanje toka v elektronskem ventilu ali
veji ventila
[VIR: IEC 60050-551:1998, 551-16-23]
3.3
kot faznega krmiljenja
kot zakasnitve toka
čas, izražen v kotnih merah, s katerim je s faznim krmiljenjem zakasnjen trenutek prevajanja toka
[VIR: IEC 60050-551:1998, 551-16-32, spremenjen – dodan je izraz "kot faznega krmiljenja"]
3.4
večperiodno krmiljenje
proces spreminjanja razmerja števila period, v katerih teče tok, in števila period brez prevajanja toka
[VIR: IEC 60050-551:1998, 551-16-31]
3.5
faktor večperiodnega krmiljenja
p
razmerje med številom period s prevajanjem ter vsoto period s prevajanjem in brez prevajanja pri
večperiodnem krmiljenju
Glej sliko 13.
[VIR: IEC 60050-551:1998, 551-16-37, spremenjen – dodan je simbol in sklic na sliko 13]
3.6
specifična fibrilacijska energija
Fe
najmanjša vrednost I · t kratkotrajnega udara enosmernega toka, ki pod danimi pogoji (tokovna pot,
srčna faza) z veliko verjetnostjo povzroči ventrikularno fibrilacijo
OPOMBA 1: F je določen z obliko udara kot integral
e
SIST IEC 60479-2 : 2020
kjer je t definiran v slikah 20 in 21. F , pomnožen z upornostjo telesa, da energijo, ki se v času udara porazgubi
i e
v človeškem telesu.
OPOMBA 2: F je izražen v Ws/Ω ali A s.
e
3.7
specifičen fibrilacijski naboj
F
q
najmanjša vrednost I · t kratkotrajnega udara enosmernega toka, ki pod podanimi pogoji (tokovna pot,
srčna faza) z veliko verjetnostjo povzroči ventrikularno fibrilacijo
OPOMBA 1: F je določen z obliko udara kot integral
q
kjer je t definiran v slikah 20 in 21.
i
OPOMBA 2: Enota za F je C ali As.
q
3.8
časovna konstanta
čas, ki je potreben, da amplituda eksponencialno padajoče veličine pade na
kratnik začetne amplitude
[VIR: IEC 60050-801:1994, 801-21-45, spremenjen – definicija je popravljena]
3.9
trajanje udara
t
i
časovni interval od začetka razelektritve do časa, ko praznilni tok pade
na 5 % svoje temenske vrednosti
OPOMBA 1: Če je časovna konstanta razelektritve kondenzatorja podana s T, je trajanje udara zaradi razelektritve
kondenzatorja enako 3T. V času trajanja udara zaradi razelektritve kondenzatorja se praktično porabi vsa energija
udara.
OPOMBA 2: Glej sliki 20 in 21.
3.10
trajanje udara
t
i
najkrajše trajanje dela udara, ki vsebuje 95 % energije
celotnega udara
3.11
prag zaznavanja
najmanjša vrednost električnega naboja, ki pod danimi pogoji povzroči zaznavanje osebi, skozi katero
teče
3.12
prag bolečine
najmanjša vrednost naboja (I · t) ali specifične energije (I ∙ t), ki se lahko brez povzročitve bolečine kot
udar uporabi na osebi, ki v roki drži veliko elektrodo
SIST IEC 60479-2 : 2020
3.13
bolečina
neprijetna izkušnja, ki je oseba, ko ji je ponovno izpostavljena, ne more več enostavno sprejeti
PRIMER: Električni udar nad pragom bolečine, opisan v 11.3, pik čebele ali cigaretna opeklina.
4 Učinki izmeničnih tokov s frekvencami nad 100 Hz
OPOMBA: Vrednosti za 50/60 Hz so podane v IEC 60479-1. Za frekvence do 100 Hz se uporabijo določbe iz IEC 60479-1.
4.1 Splošno
Z moderno električno opremo se povečuje poraba električne energije v obliki izmeničnega toka pri
frekvencah, višjih od 50/60 Hz, na primer v letalu (400 Hz), pri električnem orodju in električnem varjenju
(večinoma do 450 Hz), elektroterapiji (uporablja večinoma 4 000 Hz do 5 000 Hz) in stikalnih napajalnikih
(20 kHz do 1 MHz).
Za točko 4 je na voljo malo podatkov iz poskusov, zato naj se tukaj podane informacije štejejo samo za
začasne informacije, ki pa se lahko uporabijo za oceno tveganj v obravnavanih frekvenčnih območjih
(glej literaturo).
Sedanji poskusi potekajo v vladno podprtih projektih z namenom izkoriščanja in preiskovanja učinkov
višjih frekvenc z uporabo zadnjih tehnologij in metod, ki naj potrdijo obstoječo ekstrapolacijo faktorja
frekvence za prag ventrikularne fibrilacije (VF).
Prav tako je treba upoštevati dejstvo, da impedanca človeške kože pada približno obratno sorazmerno
s frekvenco napetosti dotika reda nekaj deset voltov, tako da je impedanca kože pri 500 Hz samo okoli
eno desetino impedance kože pri 50 Hz in se v mnogih primerih lahko zanemari. Ta impedanca
človeškega telesa pri takih frekvencah je torej znižana na njeno notranjo impedanco Z (glej IEC 60479-
i
1).
OPOMBA: Uporaba meritev temen: pri nivojih tokov, ki povzročijo fiziološke odzive zaznavanja, odzive na strah in
nezmožnost sprostitve, se fiziološki odzivi na nesinusne in periodične toke mešanih frekvenc najbolje prikažejo s
temensko vrednostjo izhodnega signala iz merilnih vezij, ki vsebujejo frekvenčno utežena vezja, kot so vezja, ki
so opisana v IEC 60990.
Ta frekvenčno utežena vezja slabijo signal skladno s faktorji frekvence, podanimi v točki 4 standarda
IEC 60479-1:2018, tako da izhodni signal ustreza stalnemu nivoju fiziološkega odziva. Slabljenje
zagotavlja, da ozki udari toka ne bi povzročili manj fiziološkega odziva zaradi kratkega trajanja njihove
temenske vrednosti. Vezje omogoča odčitavanje fiksne vrednosti neodvisno od valovne oblike ali
mešanice frekvenc, ki so potrebne za ugotavljanje uhajavega toka in oceno nivoja prisotnega ogrožanja.
Primerljivi fiziološki učinki so povzročeni z nesinusnimi in sinusnimi toki, ki pri tej merilni metodi
povzročijo enake temenske vrednosti.
1)
Značilno vezje je na voljo v IEC 60990 in v [16] .
4.2 Učinki izmeničnega toka v frekvenčnem območju nad 100 Hz do vključno 1 000 Hz
4.2.1 Prag zaznavanja
Za prag zaznavanja je faktor frekvence, podan na sliki 1.
1)
Številke v oglatih oklepajih se nanašajo na literaturo.
SIST IEC 60479-2 : 2020
Slika 1: Spreminjanje praga zaznavanja v frekvenčnem območju 50/60 Hz do 1 000 Hz
4.2.2 Prag sprostitve
Za prag sprostitve je faktor frekvence, podan v sliki 2.
Slika 2: Spreminjanje praga sprostitve v frekvenčnem območju 50/60 Hz do 1 000 Hz
SIST IEC 60479-2 : 2020
4.2.3 Prag ventrikularne fibrilacije
Pri trajanjih udara, daljših od srčnega cikla, je faktor frekvence za prag fibrilacije za vzdolžne poti toka
skozi trup telesa podan v sliki 3.
Za trajanja udarov, krajša od enega srčnega ciklusa, ni na voljo podatkov iz poskusov o učinkih
frekvence.
Slika 3: Spreminjanje praga ventrikularne fibrilacije v frekvenčnem območju 50/60 Hz do
1 000 Hz pri trajanju udarov, daljšem od enega srčnega cikla, in vzdolžnih poteh toka
skozi trup telesa
4.3 Učinki izmeničnega toka v frekvenčnem območju nad 1 000 Hz do vključno 10 000 Hz
4.3.1 Prag zaznavanja
Za prag zaznavanja je faktor frekvence podan na sliki 4.
SIST IEC 60479-2 : 2020
Slika 4: Spreminjanje praga zaznavanja v frekvenčnem območju 1 000 Hz do 10 000 Hz
4.3.2 Prag sprostitve
Za prag sprostitve je faktor frekvence podan v sliki 5.
Slika 5: Spreminjanje praga sprostitve v frekvenčnem območju 1 000 Hz do 10 000 Hz
SIST IEC 60479-2 : 2020
4.3.3 Prag ventrikularne fibrilacije
Za frekvence med 1 000 Hz in 10 000 Hz se uporabijo zahteve iz 4.4.4.
4.4 Učinki izmeničnega toka v frekvenčnem območju nad 10 000 Hz
4.4.1 Splošno
Spremembe v 4.4 niso bile izvedene z vrednostmi praga zaznavanja ali praga sprostitve za višje
frekvence. Medtem ko sta to pomembna praga, pomeni največjo nevarnost prag ventrikularne fibrilacije.
Prag fibrilacije je zato podan do 150 kHz. Preostali pragi se lahko v spodnjih točkah štejejo, da veljajo
do prikazanih frekvenčnih mej.
4.4.2 Prag zaznavanja
Prag narašča približno od 10 mA do 100 mA (efektivne vrednosti) za frekvence med 10 kHz in 100 kHz.
Pri frekvencah nad 100 kHz se občutek ščemenja, ki je značilen za zaznavanje pri nižjih frekvencah,
spremeni v občutek toplote za jakosti tokov reda nekaj sto miliamperov.
4.4.3 Prag sprostitve
Za frekvence nad 100 kHz ni niti podatkov iz poskusov niti iz poročil o dogodkih, ki se nanašajo na prag
sprostitve.
4.4.4 Prag ventrikularne fibrilacije
Pri trajanjih udara, daljših od srčnega cikla, je faktor frekvence za prag fibrilacije pri vzdolžnih poteh toka
skozi trup telesa za frekvenčno območje nad 1 000 Hz do vključno 150 kHz podan v sliki 6.
Za frekvence nad 1 kHz začenjajo prevladovati toplotni učinki.
Za trajanja udara, krajša od srčnega cikla, ni na voljo podatkov iz poskusov.
Slika 6: Spreminjanje praga ventrikularne fibrilacije pri stalnem sinusnem toku
(1 000 Hz do 150 kHz)
SIST IEC 60479-2 : 2020
4.4.5 Drugi učinki
Opekline lahko nastanejo pri frekvencah nad 100 kHz in velikostih toka reda nekaj amperov, odvisno od
trajanja toka.
5 Učinki posebnih valovnih oblik toka
5.1 Splošno
Kot je pričakovano, se učinki takih tokov na človeško telo uvrščajo med učinke enosmernih tokov in
učinke izmeničnih tokov, zato se lahko določijo enakovredne velikosti tokov glede na ventrikularno
fibrilacijo.
Točka 5 opisuje učinke toka skozi človeško telo za:
– sinusni izmenični tok z enosmernimi komponentami,
– sinusni izmenični tok s faznim krmiljenjem,
– sinusni izmenični tok z večperiodnim krmiljenjem.
OPOMBA: Druge valovne oblike se proučujejo.
Za navedene informacije se predpostavlja, da veljajo za izmenični tok s frekvencami od 15 Hz do
100 Hz.
5.2 Enakovrednost velikosti, frekvence in praga
V 5.2 se lahko šteje, da ima ogrožanje enak učinek kot enakovreden čisti sinusni izmenični tok I , ki
ev
ima naslednje značilnosti:
– Enakovrednost velikosti:
Razločevati je treba naslednje velikosti toka:
I = efektivna vrednost toka predlagane valovne oblike,
RMS
I = temenska vrednost toka predlagane valovne oblike,
p
I = medtemenska vrednost toka predlagane valovne oblike,
pp
I = efektivna vrednost sinusnega toka, ki predstavlja enak učinek kot zadevna valovna oblika.
ev
OPOMBA: Tok I je uporabljen namesto toka I , ki je podan v IEC 60479-1:2018, sliki 20 in 22, za oceno tveganja
ev B
ventrikularne fibrilacije.
Večina fizioloških učinkov je povezana s filtriranim temenskim tokom (po velikosti in trajanju) z
naravnim telesnim filtrom, določenim s frekvenčnim faktorjem F. Temenska vrednost toka naj se
uporabi v vseh primerih, razen kjer je znano razmerje med efektivno in temensko vrednostjo, to je
pri čistem sinusnem toku.
– Enakovrednost frekvenc
Obravnavana valovna oblika ima časovno periodo, enako periodi enakovredne sinusne valovne
oblike.
– Enakovrednost praga
Različni tokovni pragi (zaznavanje, nezmožnost sprostitve in ventrikularna fibrilacija) valovnih oblik,
ki zajemajo specifična razmerja med izmeničnim in enosmernim tokom, so enakovredni čistemu
sinusnemu izmeničnemu toku s tokom, ki ima karakteristiko, enakovredno I .
ev
Ta vrednost I je različna za vsakega od teh pragov.
ev
SIST IEC 60479-2 : 2020
5.3 Učinki izmeničnega toka z enosmernimi komponentami
5.3.1 Valovne oblike in frekvence ter tokovni pragi
Slika 7 kaže tipične valovne oblike, ki so obravnavane v 5.3.1. Čisti enosmerni tok in čisti izmenični tok
sta predstavljena tako dobro kot kombinirane valovne oblike različnih razmerij med izmeničnim in
enosmernim tokom.
* za trajanje udara > 1,5 srčnega cikla
** za trajanje udara < 0,75 srčnega cikla IEC
a) Kombinirane valovne oblike različnih razmerij med enosmernim in izmeničnim
tokom skupaj s pravokotnim udarom za trajanje udara > 1,5 in < 0,75 srčnega ciklusa
* za trajanje udara > 1,5 srčnega cikla
** za trajanje udara < 0,75 srčnega cikla IEC
b) Kombinirane valovne oblike različnih razmerij med izmeničnim in enosmernim
tokom mešanih frekvenc za trajanje udara > 1,5 in < 0,75 srčnega ciklusa
Slika 7: Valovne oblike tokov
SIST IEC 60479-2 : 2020
5.3.2 Prag odziva na strah
Prag odziva na strah je odvisen od raznih parametrov, kot so npr. površina telesa v stiku z elektrodo
(stična površina) in stični pogoji (suho, vlažno, tlak, temperatura), ter tudi od psiholoških značilnosti
posameznika.
Ti učinki se nanašajo na temenske vrednosti toka [13] in toke je treba frekvenčno kombinirati (frekvenca
s frekvenco), da se oceni celoten učinek. Merilno vezje je opisano v IEC 60990.
5.3.3 Prag sprostitve
Prag sprostitve je odvisen od več parametrov, kot so npr. stična površina, oblika in velikost elektrod, ter
tudi od fizioloških lastnosti posameznika.
S stališča sprostitve (stik rok s tokokrogom pod napajanjem, ki lahko traja nekaj sekund) uporablja ta
dokument sliko 5 v referenčnem Dalzielovem dokumentu [17] za ugotavljanje praga za tok sprostitve za
kombinacije izmeničnega in enosmernega toka. V tem primeru je bila frekvenca izmeničnega toka
60 Hz. Temenska vrednost izmeničnega toka 7,07 mA (5 mA efektivno za sinusni tok) in vrednost
enosmernega toka 30 mA sta bili uporabljeni kot praga za tok dotika za čisti izmenični oziroma
enosmerni tok. Ta praga se štejeta, da ustrezata in predstavljata celotno populacijo (vključno z otroki)
glede nezmožnosti do sprostitve.
Enačba I temensko = 7,176 × exp (−0,143 4 × DC) − 0,106 1 predstavlja to kombinacijo primerov
AC
izmeničnega in enosmernega toka in se lahko uporabi za izračun rezultata poljubne kombinacije
izmeničnega in enosmernega toka v določenem območju.
Naslednja slika 8 kaže informacijo, ki jo je dal Dalziel.
Slika 8: Pragi sprostitve za moške, ženske in otroke
Gornje krivulje se lahko opišejo z enačbo, ki ustreza tem podatkom.
Enačba I = 12,890 5 × exp (−0,069 39 × DC) − 0,190 5 predstavlja 99,5-odstotkovno krivuljo za
AC temensko
moške.
Enačba I = 8,523 × exp (−0,104 9 × DC) − 0,126 predstavlja 99,5-odstotkovno krivuljo za ženske.
AC temensko
SIST IEC 60479-2 : 2020
Enačba I = 6,394 5 × exp (−0,138 8 × DC) − 0,094 5 predstavlja 99,5-odstotkovno krivuljo za
AC temensko
otroke.
Iz praktičnih razlogov nekateri standardi dovoljujejo kot izjemo nekaj valovitosti (npr. do 10 %) v
enosmernem napajanju.
Slika 9 kaže prag sprostitve, izražen v mA temensko, za kombinacije 50/60 Hz sinusnega izmeničnega
toka in enosmernega toka. Teme sestavljenega izmeničnega in enosmernega vala v mA pri pragu
sprostitve, ocenjeno za populacijo ljudi, vključno z otroki, je prikazano kot funkcija enosmerne
komponente v mA.
Slika 9 je predstavljena z enačbo za sestavljeni tok:
I + I = 7,176 × exp (−0,143 4 × DC) − 0,106 1 + DC
AC temensko DC
Slika 9: 99,5-odstotni prag sprostitve za kombinacije sinusnega izmeničnega toka 50/60 Hz in
enosmernega toka
Ti učinki se nanašajo na temenske vrednosti toka [6] in toke je treba frekvenčno kombinirati (frekvenca
s frekvenco), da se ovrednoti celoten učinek. Merilno vezje je opisano v IEC 60990.
5.3.4 Prag ventrikularne fibrilacije
5.3.4.1 Valovne oblike s specifičnimi razmerji med izmeničnim in enosmernim tokom
Za nevarnost fibrilacije se lahko šteje, da je približno enaka kot pri enakovrednem sinusnem izmeničnem
toku I z naslednjimi značilnostmi:
ev
a) za trajanja udara, daljša od približno 1,5-kratne periode srčnega cikla, je I efektivna vrednost
ev
sinusnega izmeničnega toka, ki ima isto medtemensko vrednost I kot tok obravnavane valovne
pp
oblike.
b) za trajanja udara, krajša od približno 0,75-kratnika periode enega srčnega cikla, je I efektivna
ev
vrednost sinusnega izmeničnega toka, ki ima enako temensko vrednost I kot tok obravnavane
p
valovne oblike;
SIST IEC 60479-2 : 2020
OPOMBA 1: Ta soodvisnost je manj uporabna, ko se razmerje med izmeničnim in enosmernim tokom zmanjša. Za čiste
udare enosmernega toka v trajanju manj od 0,1 s je prag enakovreden ustrezni efektivni vrednosti
izmeničnega toka (glej IEC 60479-1:2018, slika 20 ali slika 22).
c) v območju trajanja od 0,75- do 1,5-kratne pe
...
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