SIST EN 50647:2017

SLOVENSKI STANDARD
SIST EN 50647:2017
01-september-2017
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Basic standard for the evaluation of workers' exposure to electric and magnetic fields
from equipment and installations for the production, transmission and distribution of
electricity
Basisnorm für die Evaluierung der beruflichen Exposition gegenüber elektrischen und
magnetischen Feldern ausgehend von Komponenten und Anlagen zur Erzeugung,
Übertragung und Verteilung elektrischer Energie
Norme fondamentale pour l’évaluation de l’exposition des travailleurs aux champs
électriques et magnétiques produits par les équipements et installations de production,
transport et distribution d’électricité
Ta slovenski standard je istoveten z: EN 50647:2017
ICS:
13.100 Varnost pri delu. Industrijska Occupational safety.
higiena Industrial hygiene
17.220.01 Elektrika. Magnetizem. Electricity. Magnetism.
Splošni vidiki General aspects
SIST EN 50647:2017 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 50647:2017

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SIST EN 50647:2017

EUROPEAN STANDARD EN 50647

NORME EUROPÉENNE

EUROPÄISCHE NORM
June 2017
ICS 17.220.20; 17.240
English Version
Basic standard for the evaluation of workers' exposure to electric
and magnetic fields from equipment and installations for the
production, transmission and distribution of electricity
Norme fondamentale pour l'évaluation de l'exposition des Basisnorm für die Evaluierung der beruflichen Exposition
travailleurs aux champs électriques et magnétiques produits gegenüber elektrischen und magnetischen Feldern
par les équipements et installations de production, transport ausgehend von Komponenten und Anlagen zur Erzeugung,
et distribution d'électricité Übertragung und Verteilung elektrischer Energie
This European Standard was approved by CENELEC on 2017-04-10. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden,
Switzerland, Turkey and the United Kingdom.



European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN 50647:2017 E

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SIST EN 50647:2017
EN 50647:2017 (E)
Contents Page
European foreword . 4
3.1 Terms and definitions . 6
3.2 Physical quantities and units . 8
3.3 Abbreviations . 8
6.1 General . 11
6.2 Exposure assessment regarding external fields . 11
6.2.1 General . 11
6.2.2 Harmonics of magnetic field. 12
6.2.3 Harmonics of electric field . 12
6.3 Numerical calculation of induced electric fields inside the human body . 13
8.1 General . 13
8.2 Simplified criteria for compliance with action levels . 15
8.2.1 General . 15
8.2.2 Magnetic fields . 15
8.2.3 Electric fields . 16
8.3 Assessment using measurements or calculations . 17
8.3.1 General . 17
8.3.2 Magnetic fields . 17
8.3.3 Electric fields . 18
9.1 General . 19
9.2 Simplified criteria for compliance with exposure limit values . 19
9.2.1 General . 19
9.2.2 Magnetic fields . 20
9.2.3 Electric fields . 21
9.3 Assessment using dosimetry and considerations for non-uniform fields . 21
13.1 Workers at particular risk . 23
13.2 Other requirements . 23
Annex A (informative) Assessment of harmonics in magnetic fields . 24
A.1 Introduction . 24
A.2 Assessment Method using TEI . 24
A.3 Assessment using the weighted peak function . 26
A.4 Simplified assessment procedure for public grids . 28
Annex B (normative) 50 Hz magnetic field sources in the environment of equipment and installations
for production, transmission and distribution of electricity . 29
B.1 General . 29
B.2 Currents in single conductors . 29
B.3 Currents in circuits . 31
B.4 Assessing magnetic fields exposures . 31
B.5 Check list for assessing compliance for magnetic fields . 33
Annex C (informative) Examples of application of the different assessment criteria . 34
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C.1 Assessment for air-cored reactors: Simplified calculation of the magnetic field under a

vertical air-cored self-inductance . 34
C.2 Assessment for insulated cables: Calculation of compliance distances for typical XLPE

cables. 36
C.3 Assessment for exposure to electric fields considering different coupling conditions . 38
Annex D (informative) Method for deriving Exposure-Limit-Equivalent-Fields (LEFs) . 41
D.1 Introduction . 41
D.2 Method . 41
D.3 Selection of the reference model: . 42
D.4 Reference organs and data . 42
D.5 Uncertainty assessment . 43
D.6 Deriving the Exposure-Limit-Equivalent-Field (LEF) . 44
Annex E (informative) Considerations about DC magnetic fields in electrical companies . 45
E.1 Introduction . 45
E.2 Exposure of workers to DC magnetic field in electrical companies . 45
E.3 Attention points . 45
Annex F (informative) contact currents . 46
F.1 Introduction . 46
F.2 Influence of electric fields . 46
F.2.1 General . 46
F.2.2 Person isolated (at floating potential), capacitive coupling to ground . 46
F.2.3 Person at earth potential, isolated object . 47
F.2.4 Spark discharges . 48
F.3 Influence of magnetic fields . 48
F.3.1 General . 48
F.3.2 Working adjacent to live circuits . 48
F.4 Summary . 49
Annex G (informative) Exposure during transient and fault conditions . 50
G.1 Introduction . 50
G.2 Faults . 50
G.2.1 Overview . 50
G.2.2 Short-circuit currents during faults . 50
G.2.3 Prevention and protection against faults. 50
G.2.4 Magnetic field exposures during faults. 51
G.3 Switching transients . 51
G.4 Lightning strikes . 51
G.5 Inrush currents . 51
G.6 Compliance of short-duration events with the Directive. 52
Bibliography . 53
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EN 50647:2017 (E)
European foreword
This document [EN 50647:2017] has been prepared by CLC/TC 106X “Electromagnetic fields in the human
environment”.
The following dates are fixed:
• latest date by which this document has to be (dop) 2018-04-10
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) 2020-04-10
conflicting with this document have to
be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a mandate given to CENELEC by the European Commission and
the European Free Trade Association.
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1 Scope
This European Standard provides a general procedure to assess workers’ exposure to electric and magnetic
fields (EMF) in work places associated with the production, transmission and distribution of electric energy,
and to demonstrate compliance with exposure limit values and action levels as stated in the Council and
European Parliament “EMF” Directive 2013/35/EU [11].
NOTE 1 The Council and European Parliament Directive 2013/35/EU will be transposed into national legislation in all
the EU member countries. It is important that users of this standard consult the national legislation related to this
transposition in order to identify the national regulations and requirements. These national regulations and requirements
may have additional requirements that are not covered by this standard
It has the role of a specific workplace standard. It takes into account the non-binding application guide for
implementing the EMF Directive [10] and it defines the assessment procedures and compliance criteria
applicable to the electric industry.
The frequency range of this standard covers from DC to 20 kHz, which is sufficient to include the power
frequency used for electric power supply systems throughout Europe (50 Hz) and the various harmonics and
inter-harmonics occurring in the supply system. In this extremely low frequency range, electric and magnetic
fields are independent and, therefore, they both have to be addressed in the exposure assessment.
NOTE 2 Electrical companies also use radio frequency transmissions to operate and maintain their networks and
power plants. Similarly, other exposures to EMF may occur during maintenance operations, for instance, due to the use
of hand-held electrical tools. All these EMF sources are outside the scope of this standard.
NOTE 3 Regarding EMF in the low frequency range, the scientific basis of the EMF directive is the ICNIRP health
guidelines published in 2010 [13]. Reference is made to this scientific basis when necessary for justifying or clarifying
some of the technical statements of the present document.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
EN 61786-1, Measurement of DC magnetic, AC magnetic and AC electric fields from 1 Hz to 100 kHz with
regard to exposure of human beings - Part 1: Requirements for measuring instruments (IEC 61786-1)
EN 50527-1, Procedure for the assessment of the exposure to electromagnetic fields of workers bearing
active implantable medical devices - Part 1: General
EN 50527-2-1, Procedure for the assessment of the exposure to electromagnetic fields of workers bearing
active implantable medical devices - Part 2-1: Specific assessment for workers with cardiac pacemakers
IEC 61786-2, Measurement of DC magnetic, AC magnetic and AC electric fields from 1 Hz to 100 kHz with
regard to exposure of human beings - Part 2: Basic standard for measurements
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3 Terms, definitions, physical quantities, units and abbreviations
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1.1
action level
AL
operational level established for the purpose of simplifying the process of demonstrating compliance with the
relevant exposure limit value or, where appropriate, to take relevant protection or prevention measures
Note 1 to entry: “Reference levels” as defined in the European Recommendation 1999/519/EC [3] for limiting the
exposure of the public and in ICNIRP Health Guidelines [13] are based on the same approach as Action Levels and the
two terms are defined to achieve the same objective.
Note 2 to entry: For electric fields, “Low ALs” and “High ALs” are levels which relate to the specific protection or
prevention measures specified in the EMF Directive [11].
Note 3 to entry: The Low AL for external electric field is based both on limiting the internal electric field below ELVs and
on limiting spark discharges in the working environment. Below the High AL, the internal electric field does not exceed
ELVs and annoying spark discharges are prevented, provided that the relevant protection measures are taken.
Note 4 to entry: For magnetic fields, “Low ALs” are levels which relate to the sensory effects ELVs and “High ALs” to
the health effects ELVs.
Note 5 to entry: Compliance with the ALs will ensure compliance with the relevant ELVs. If the assessed exposure
values are higher than the ALs, it does not necessarily follow that the ELVs have been exceeded, but a more detailed
analysis is necessary to demonstrate compliance with the ELVs.
Note 6 to entry: ALs may not provide adequate protection to workers at particular risks, for whom a particular risk
assessment shall be performed.
3.1.2
compliance distance
distance from a source of field that ensures respect of the relevant exposure limit values or action levels
Note 1 to entry: Working at distances smaller than compliance distances requires a specific assessment.
3.1.3
contact current
current between a person in established contact with a conductive object, resulting from the inductive or
capacitive coupling between the field and the person and/or object, and expressed in amperes (A)
Note 1 to entry: The EMF directive [11] specifies limits for the steady-state value of the contact current.
3.1.4
electric field
constituent of an electromagnetic field which is characterized by the electric field strength E together with the
electric flux density D
Note 1 to entry: In French, the term “champ électrique ” is also used for the quantity electric field strength.
[SOURCE: IEV, ref 121-11-67]
3.1.5
exposure index
EI
assessed exposure divided by the relevant action level or exposure limit value
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3.1.6
exposure-limit-equivalent field
LEF
magnitude of uniform external electric or magnetic field that exposes the person to the sensory or health
effects ELV
Note 1 to entry: The numerical values of LEFs are derived from dosimetry.
3.1.7
exposure limit value
ELV
limit which is based directly on established health effects and biological considerations
Note 1 to entry: In the frequency range covered by the present standard, ELVs are expressed in terms of induced
electric fields except between 0 Hz and 1 Hz where the ELV is given in terms of external magnetic field.
Note 2 to entry: “Basic restrictions” as defined in the European Recommendation 1999/519/EC [3] for limiting the
exposure of the public and in ICNIRP Health Guidelines [13] are based on the same approach as Exposure Limit Values
and the two terms are defined to achieve the same objective.
3.1.8
exposure limit values for sensory effects (sensory effects ELVs)
ELVs above which workers might be subject to transiently disturbed sensory perceptions, i.e. retinal
phosphenes and minor changes in brain functions
Note 1 to entry: The sensory effects relate only to the central nervous system of the head. Exceeding sensory effects
ELVs is allowed under controlled conditions for informed workers.
3.1.9
exposure limit values for health effects (health effects ELVs)
ELVs above which workers might be might be subject to adverse health effects, such as stimulation of nerve
and muscle tissue
Note 1 to entry: Compliance with health effects ELVs will ensure that workers exposed to electric and magnetic fields
are protected against all established adverse health effects.
Note 2 to entry: The threshold for muscle excitation is far higher than for nerve excitation, and therefore the directive
[11], consistently with its scientific basis [13], considers limits to prevent only nerve excitation, as they are conservative
with regard to muscle excitation. As a result, the health effects relate to the peripheral nervous system, i.e. the whole
body.
3.1.10
induced electric field
electric field inside a human body resulting directly from an exposure to an external source of electric or
magnetic field
3.1.11
magnetic field
constituent of an electromagnetic field which is characterized by the magnetic field strength H together with
the magnetic flux density B
Note 1 to entry: In French, the term “champ magnétique” is also used for the quantity magnetic field strength.
Note 2 to entry: In this document, the term magnetic field is used for magnetic flux density.
[SOURCE: IEV ref 121-11-69]
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3.1.12
total exposure index
TEI
sum of all exposure indexes (e.g. at different frequencies, or from different sources) of either electric or
magnetic field
Note 1 to entry: If the total exposure index is less than one, the exposure is compliant.
Note 2 to entry: Using the arithmetic sum makes the TEI a conservative assessment of exposure.
3.1.13
unperturbed field
field at a point that would exist in the absence of persons or in the absence of movable objects which are not
necessary for the work progress
Note 1 to entry: All limits expressed in terms of fields external to the human body refer to the unperturbed field.
[SOURCE: EN 61786-1:2014, 3.3.1]
3.2 Physical quantities and units
For the purposes of this document, the physical quantities and units given in Table 1 apply.
Table 1 — Physical quantities and units
Quantity Symbol Unit Comments
Electric field strength E V/m
Magnetic flux density B T µT is more usually used at 50 Hz
Contact current I A
c
3.3 Abbreviations
AL action level
CNS central nervous system
DC direct current
EI exposure index
ELV exposure limit value
GIS gas insulated substation
HV high voltage
LEF exposure limit equivalent field
PNS peripheral nervous system
TEI total exposure index
WPR worker at particular risk
rms root mean square
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4 Assessment procedure
According to Article 4 of EU Directive 2013/35/EU [11] “.the employer shall assess all risks for workers
arising from electromagnetic fields at the workplace and, if necessary, measure or calculate the levels of
electromagnetic fields to which workers are exposed.In workplaces open to the public it is not necessary
for the exposure assessment to be carried out if an evaluation has already been undertaken in accordance
with the provisions on the limitation of exposure of the general public to electromagnetic fields, if the
restrictions specified in those provisions are respected for workers and if the health and safety risks are
excluded. Where equipment intended for the public use is used as intended and complies with Union law on
products that establishes stricter safety levels than those provided for by this Directive, and no other
equipment is used, these conditions are deemed to be met.”
Electrical equipment for the production, transmission and distribution of electricity is highly standardized and
a few general assessments may cover many sites which have similar equipment and work positions.
Therefore, a systematic and thorough assessment of every site containing electrical equipment is not
necessary. For a given site, the risk assessment should be limited to any specific equipment or work
positions not covered by the general assessments.
The exposure assessment shall be updated if any modification to the installation, the working environment or
the work practice significantly affects the EMF exposure conditions.
In electrical companies, many workplaces are exposed simultaneously to electric and magnetic fields. The
internal electric fields induced simultaneously by external electric and magnetic fields are vectors, which
most often are neither collinear in space nor coincident in phase. ICNIRP’s position [13] is that situations
where these field vectors are collinear and in phase “are judged to be very infrequent taking into account the
great difference in the distribution of the electrically and magnetically induced electric fields“.
Therefore, when assessing compliance with the Directive according to the present standard, exposure to low
frequency electric and magnetic fields shall be considered separately and not additively.
This clause gives a general procedure for the exposure assessment of a work place, which is presented in
Figure 1 as a flowchart. It shows all the possible methods to demonstrate compliance with the EMF directive
[11]. The different steps of this flowchart are developed in Clauses 5, 7, 8, 9, 10 and 13.
Compliance can be demonstrated using any of the possible methods. For example, in some cases it might
be more simple and efficient to demonstrate compliance using measurements (e.g. subclause 8.3) rather
than identifying all the electrical equipment and checking whether it meets the criteria for simplified
assessment (e.g. subclause 8.2).
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Figure 1 — General flowchart of the compliance assessment procedure
5 Collection of technical data
For assessing compliance, it is necessary to characterize the workplace in terms of EMF sources and of
work positions in relation to them, and of the work practices involved. In terms of t
...