SIST EN 50445:2008
(Main)Product family standard to demonstrate compliance of equipment for resistance welding, arc welding and allied processes with the basic restrictions related to human exposure to electromagnetic fields (0 Hz - 300 GHz)
Product family standard to demonstrate compliance of equipment for resistance welding, arc welding and allied processes with the basic restrictions related to human exposure to electromagnetic fields (0 Hz - 300 GHz)
This product family standard applies to equipment for resistance welding, arc welding and allied processes designed for use in industrial or domestic environments, including welding power sources, wire feeders and ancillary equipment, e.g. torches, liquid cooling systems and arc striking and stabilising devices.
Produktfamiliennorm zur Konformitätsprüfung von Einrichtungen zum Widerstandsschweißen, Lichtbogenschweißen und artverwandten Prozessen in Bezug auf die bei der Exposition durch elektromagnetische Felder anzuwendenden Basisgrenzwerte (0 Hz - 300 GHz)
Diese Produktfamiliennorm gilt für Einrichtungen zum Widerstandsschweißen, Lichtbogenschweißen und für verwandte Prozesse für den Gebrauch im Industrie- oder Wohnbereich, einschließlich Schweißstromquellen, Drahtvorschubgeräte und Zusatzeinrichtungen, wie z.B. Brenner, Flüssigkeits-kühlgeräte und Lichtbogenzünd- und Stabilisierungseinrichtungen. ANMERKUNG 1 Verwandte Prozesse sind beispielsweise Widerstandshart- und Weichlöten, Widerstandserwärmen mit zu Widerstandsschweißeinrichtungen vergleichbaren Mitteln, Elektrolichtbogenschneiden und Lichtbogenspritzen. Der abgedeckte Frequenzbereich ist 0 Hz bis 300 GHz. Diese Produktfamiliennorm darf zum Nachweis der Einhaltung der Anforderungen der Richtlinie 2006/95/EG [1] (zum In Verkehrbringen von elektrischen Betriebsmitteln am Europäischen Markt) hinsichtlich der Begrenzung der Exposition von Personen durch elektromagnetische Felder (EMF), verwendet werden. Die Richtlinie enthält weitere Anforderungen, die nicht in dieser Produktfamiliennorm enthalten sind. ANMERKUNG 2 Die Richtlinie 2006/95/EG [1], Artikel 2, fordert, dass die Mitgliedsstaaten alle zweckdienlichen Maßnahmen treffen um sicherzustellen, dass elektrische Einrichtungen nur dann in Verkehr gebracht werden können, wenn sie in dem in der Gemeinschaft gegebenen Stand der Sicherheitstechnik entsprechen. Diese Produktfamiliennorm kann auch für die Bewertung hinsichtlich der Anforderungen der Richtlinie 2004/40/EG [3] über Mindestvorschriften zum Schutz von Sicherheit und Gesundheit der Arbeitnehmer vor der Gefährdung durch physikalische Einwirkungen (elektromagnetische Felder) oder der Empfehlung 1999/519/EG [2] zur Begrenzung der Exposition der Bevölkerung gegenüber elektromagnetischen Feldern verwendet werden, wenn keine anderen relevanten Feldquellen in direkter Nähe vorhanden sind. Wenn andere relevante Feldquellen vorhanden sind, ist eine zusätzliche Bewertung erforderlich. ANMERKUNG 3 Es sollte beachtet werden, dass der Lieferant spezifischer Einrichtungen möglicherweise nicht die gesamte Expositionsumgebung, in der diese Einrichtung zum Einsatz kommt, kennt. Diese Produktfamiliennorm kann nur die Exposition von Personen durch die zu beurteilende spezifischen Einrichtung bewerten, wenn diese nach den Richtlinien des Lieferanten verwendet wird. ANMERKUNG 4 Bewertungsverfahren für Arbeitsplätze mit mehreren Feldquellen sind in EN 50499 [7] zu finden. Für Produkte, für die diese Produktfamiliennorm gilt, können weitere Normen anwendbar sein. Im Besonderen ist diese Norm weder dafür vorgesehen, elektromagnetische Verträglichkeit mit anderen Einrichtungen nachzuweisen, noch spezifiziert sie andere Produktsicherheitsanforderungen als jene, die sich speziell auf die Exposition von Personen durch elektromagnetische Felder beziehen. ANMERKUNG 5 Konformitätsnachweisverfahren sind nicht für den gesamten Frequenzbereich festgelegt.
Norme de famille de produit pour démontrer la conformité d’un équipement pour le soudage par résistance, le soudage à l’arc et les techniques connexes avec les restrictions de base concernant l'exposition des personnes aux champs électromagnétiques (0 Hz - 300 GHz)
La présente norme de famille de produit s’applique au matériel de soudage par résistance, de soudage à l’arc et techniques connexes, conçu pour l’emploi dans les environnements industriels ou domestiques, y compris les sources de courant de soudage, les dévidoirs et équipements auxiliaires, par exemple les torches, les systèmes de refroidissement par liquide et les dispositifs d’amorçage et de stabilisation de l’arc. NOTE 1 Des techniques connexes sont, par exemple, le brasage fort et tendre par résistance, le chauffage par résistance atteint par des moyens comparables au matériel de soudage par résistance, coupage et projection à l’arc électrique. La gamme de fréquences couverte est comprise entre 0 Hz et 300 GHz. Cette norme de famille de produit peut être utilisée pour démontrer la conformité avec les exigences de la Directive 2006/95/CE [1] (nécessaire pour la mise sur le marché européen de matériel de soudage électrique) concernant la limitation de l’exposition humaine aux champs électromagnétiques (EMF). Il existe des exigences supplémentaires dans la Directive, qui ne sont pas incluses dans cette norme de famille de produit. NOTE 2 L'Article 2 de la Directive 2006/95/CE [1] stipule que les Etats Membres prennent toutes mesures utiles pour que le matériel électrique puisse être mis sur le marché à condition qu'il soit construit conformément aux règles de l'art en matière de sécurité en vigueur dans la Communauté. La présente norme de famille de produit peut également être utilisée pour l’évaluation selon les exigences de la Directive 2004/40/CE [3] concernant les prescriptions minimales de sécurité et de santé relatives à l'exposition des travailleurs, aux risques dus aux agents physiques (champs électromagnétiques) ou de la Recommandation 1999/519/CE [2] relative à la limitation de l'exposition du public aux champs électromagnétiques, à condition qu'il n'y ait pas d'autres sources de champ pertinentes dans la proximité immédiate. Lorsque d'autres sources de champ sont présentes, une évaluation supplémentaire sera nécessaire. NOTE 3 Il faut noter que le fournisseur de matériel spécifique pourrait ne pas connaître l’environnement total d’exposition dans lequel le matériel sera utilisé. Cette norme de famille de produit peut uniquement être utilisée pour évaluer l’exposition humaine provenant du matériel spécifique sous évaluation lorsqu’il est utilisé conformément aux recommandations du fournisseur. NOTE 4 Des procédures d'évaluation pour les postes de travail sont indiquées dans la EN 50499 [7]. D’autres normes peuvent s’appliquer à des produits couverts par cette norme de famille de produit. En particulier cette norme ne peut pas être utilisée pour démontrer la compatibilité électromagnétique avec d’autres matériels et elle ne spécifie aucune exigence de sécurité de produit autre que celles relevant spécifiquement de l’exposition humaine aux champs électromagnétiques. NOTE 5 Les procédures destinées à démontrer la conformité ne sont pas spécifiées sur toute la gamme de fréquences.
Standard za družino proizvodov za prikaz skladnosti opreme za uporovno varjenje, obločno varjenje in sorodne procese z osnovnimi mejnimi vrednostmi glede izpostavljenosti ljudi elektromagnetnim sevanjem (0 Hz–300 GHz)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 50445:2008
01-junij-2008
6WDQGDUG]DGUXåLQRSURL]YRGRY]DSULND]VNODGQRVWLRSUHPH]DXSRURYQRYDUMHQMH
REORþQRYDUMHQMHLQVRURGQHSURFHVH]RVQRYQLPLPHMQLPLYUHGQRVWPLJOHGH
L]SRVWDYOMHQRVWLOMXGLHOHNWURPDJQHWQLPVHYDQMHP +]±*+]
Product family standard to demonstrate compliance of equipment for resistance welding,
arc welding and allied processes with the basic restrictions related to human exposure to
electromagnetic fields (0 Hz - 300 GHz)
Produktfamiliennorm zur Konformitätsprüfung von Einrichtungen zum
Widerstandsschweißen, Lichtbogenschweißen und artverwandten Prozessen in Bezug
auf die bei der Exposition durch elektromagnetische Felder anzuwendenden
Basisgrenzwerte (0 Hz - 300 GHz)
Norme de famille de produit pour démontrer la conformité d’un équipement pour le
soudage par résistance, le soudage à l’arc et les techniques connexes avec les
restrictions de base concernant l'exposition des personnes aux champs
électromagnétiques (0 Hz - 300 GHz)
Ta slovenski standard je istoveten z: EN 50445:2008
ICS:
17.220.01 Elektrika. Magnetizem. Electricity. Magnetism.
Splošni vidiki General aspects
25.160.10 Varilni postopki in varjenje Welding processes
SIST EN 50445:2008 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 50445:2008
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SIST EN 50445:2008
EUROPEAN STANDARD
EN 50445
NORME EUROPÉENNE
February 2008
EUROPÄISCHE NORM
ICS 17.220.01; 25.160.10
English version
Product family standard to demonstrate compliance of equipment
for resistance welding, arc welding and allied processes with the basic
restrictions related to human exposure to electromagnetic fields
(0 Hz - 300 GHz)
Norme de famille de produit pour Produktfamiliennorm zur
démontrer la conformité d’un équipement Konformitätsprüfung von Einrichtungen
pour le soudage par résistance, zum Widerstandsschweißen,
le soudage à l’arc et les techniques Lichtbogenschweißen und artverwandten
connexes avec les restrictions de base Prozessen in Bezug auf die bei der
concernant l'exposition des personnes Exposition durch elektromagnetische
aux champs électromagnétiques Felder anzuwendenden Basisgrenzwerte
(0 Hz - 300 GHz) (0 Hz - 300 GHz)
This European Standard was approved by CENELEC on 2008-02-01. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50445:2008 E
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SIST EN 50445:2008
EN 50445:2008 – 2 –
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 26A, Electric arc
welding equipment.
The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50445
on 2008-02-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by p ublication of an identical
national standard or by endorsement (dop) 2008-02-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2008-02-01s
This European Standard is to be read in conjunction with EN 50444 and EN 50505. The latter was
prepared by the Technical Committee CENELEC TC 26B, Electric resistance welding.
This European Standard has been prepared under mandates M/305 and M/351 given to CENELEC by
the European Commission and the European Free Trade Association.
__________
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Contents
1 Scope .4
2 Normative references .4
3 Terms and definitions .5
4 Compliance criteria and exposure limits .6
4.1 Background .6
4.2 Equipment for use by the general public.7
4.3 Equipment for occupational use.7
4.4 Equipment for occupational use in a public area .7
4.5 Exposure of persons wearing cardiac pacemakers or other medical implants.7
4.6 Projectile risk.7
4.7 Touch currents .8
5 Compliance assessment.8
5.1 General.8
5.1.1 Measurement and calculation.8
5.1.2 Time averaging .8
5.1.3 Spatial averaging .8
5.1.4 Assessment of equipment with pulsed or non-sinusoidal welding current .9
5.1.5 Assessment of equipment with multiple welding current waveforms .9
5.2 Assessment of EMF .9
5.2.1 General considerations.9
5.2.2 Electric field.10
5.2.3 Magnetic field measurements to show compliance with reference levels.10
5.2.4 Calculations to show compliance with reference levels.10
5.2.5 Calculations to show compliance with basic restrictions .10
6 Information to be supplied with the apparatus.10
7 Marking .11
8 Uncertainty of assessment.11
8.1 Using uncertainty for comparison with limits.11
8.2 Permissible expanded uncertainties .12
Annex A (informative) General public basic restrictions and reference levels.13
Annex B (informative) Occupational basic restrictions and reference levels .15
Annex C (informative) Example for general EMF information.17
Bibliography.18
Tables
Table 1 – Summation parameters.9
Table 2 – Permissible expanded uncertainties.12
Table A.1 – General public basic restrictions for electric, magnetic and electromagnetic fields .13
Table A.2 – General public reference levels for electric, magnetic and electromagnetic fields.14
Table B.1 – Occupational basic restrictions for electric, magnetic and electromagnetic fields.15
Table B.2 – Occupational reference levels for time varying electric and magnetic fields .16
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EN 50445:2008 – 4 –
1 Scope
This product family standard applies to equipment for resistance welding, arc welding and allied
processes designed for use in industrial or domestic environments, including welding power sources,
wire feeders and ancillary equipment, e.g. torches, liquid cooling systems and arc striking and
stabilising devices.
NOTE 1 Allied processes are for example resistance hard and soft soldering, resistance heating by means comparable to
resistance welding equipment, electric arc cutting and arc spraying.
The frequency range covered is 0 Hz to 300 GHz.
This product family standard may be used to demonstrate compliance with the requirements of
Directive 2006/95/EC [1] (needed for placing electric welding equipment on the European market),
with regard to the limitation of human exposure to electromagnetic fields (EMF). There are additional
requirements in the Directive, which are not included in this product family standard.
NOTE 2 The Directive 2006/95/EC [1], Article 2, stipulates that the Member States take all appropriate measures to ensure
that electrical equipment may be placed on the market only if, having been constructed in accordance with good engineering
practice in safety matters in force in the Community.
This product family standard may also be used for assessment regarding the requirements of
Directive 2004/40/EC [3] on the minimum health and safety requirements regarding the exposure of
workers to the risks arising from physical agents (electromagnetic fields) or Recommendation
1999/519/EC [2] on the limitation of exposure of the general public to electromagnetic fields, provided
that no other relevant field sources are present in close proximity. If other relevant field sources are
present, additional assessment is necessary.
NOTE 3 It should be noted that the supplier of specific equipment might not know the overall exposure environment in which
the equipment is being used. This product family standard can only be used to assess human exposure from the specific
equipment under evaluation when being used in accordance with the suppliers guidelines.
NOTE 4 Assessment procedures for workplaces with multiple field-sources may be found in EN 50499 [7].
Other standards may apply to products covered by this product family standard. In particular this
standard can not be used to demonstrate electromagnetic compatibility with other equipment; nor
does it specify any product safety requirements other than those specifically related to human
exposure to electromagnetic fields.
NOTE 5 Procedures to demonstrate compliance are not specified for the whole frequency range.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 50392 Generic standard to demonstrate the compliance of electronic and
electrical apparatus with the basic restrictions related to human exposure
to electromagnetic fields (0 Hz – 300 GHz)
EN 50444 Basic standard for the evaluation of human exposure to electromagnetic
fields from equipment for arc welding and allied processes
EN 50505 Basic standard for the evaluation of human exposure to electromagnetic
fields from equipment for resistance welding and allied processes
EN 60974-1 Arc welding equipment – Part 1: Welding power sources (IEC 60974-1)
EN 60974-6 Arc welding equipment – Part 6: Limited duty manual metal arc welding
power sources (IEC 60974-6)
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3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
action values
magnitude of directly measurable parameters at which one or more of the specified measures in
Directive 2004/40/EC [3] must be undertaken
3.2
arc welding power source
equipment for supplying current and voltage and having the required characteristics suitable for arc
welding and allied processes
NOTE 1 An arc welding power source may also supply services to other equipment and auxiliaries e.g. auxiliary power, cooling
liquid, consumable arc welding electrode and gas to shield the arc and the welding area.
NOTE 2 In the following text, the term “welding power source” is used.
3.3
basic restrictions
exposure limit values
restrictions on exposure to electric, magnetic and electromagnetic fields that are based directly on
established health effects and biological considerations
3.4
compliance boundary
spatial border outside which any point of investigation is deemed to be compliant
3.5
EMF
electric, magnetic or electromagnetic field
3.6
expert
competent person
skilled person
person who can judge the work assigned and recognize possible hazards on the basis of professional
training, knowledge, experience and knowledge of the relevant equipment
NOTE Several years of practice in the relevant technical field may be taken into consideration in assessment of professional
training.
3.7
induced current density (J)
electromagnetic field induced current per unit area inside the body
3.8
industrial and professional use
use intended only for experts or instructed persons
3.9
instructed person
person informed about the tasks assigned and about the possible hazards involved in neglectful
behaviour
NOTE If necessary, the person has undergone some training.
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3.10
magnetic flux density (B)
magnitude of a field vector that is equal to the magnetic field strength H multiplied by the permeability
µ of the medium
B = µ H
3.11
point of investigation (POI)
location in space at which the value of the E-field, H-field or power density is evaluated
NOTE This location is defined in cartesian, cylindrical or spherical co-ordinates relative to the reference point on the EUT.
3.12
reference levels
directly measurable quantities, derived from basic restrictions, provided for practical exposure
assessment purposes
NOTE Respect of the reference levels will ensure respect of the relevant basic restriction. If the reference levels are exceeded,
it does not necessarily follow that the basic restriction will be exceeded.
3.13
resistance welding equipment
equipment for supplying current and voltage and having the required characteristics suitable for
resistance welding and allied processes
4 Compliance criteria and exposure limits
4.1 Background
Reference levels are provided for practical exposure assessment purposes to determine whether the
basic restrictions are likely to be exceeded. If the measured value exceeds the reference level, it does
not necessarily follow that the basic restriction will be exceeded.
In some situations, it may be necessary to show compliance with the basic restrictions directly, but it
may also be possible to derive compliance criteria that allow a simple measurement or calculation to
demonstrate compliance with the basic restriction. Often these compliance criteria can be derived
using realistic assumptions about conditions under which exposures from a device may occur, rather
than the conservative assumptions that underlie the reference levels.
NOTE 1 The limit is the basic restriction.
The exposure assessment results for the points of investigation specified in the basic standards
EN 50444 and EN 50505 shall be below the relevant limits. For equipment designed exclusively for
mechanized or robotic applications the points of investigation (reflecting the normal operator position
for manual welding) defined in the basic standards EN 50444 and EN 50505 are not applicable. The
manufacturer of this type of equipment shall define specific points of investigation.
As the highest exposure from equipment covered by the scope of this standard is to be expected in
the inductive near-field, summation effects of maximum exposure levels of various pieces of
equipment, e.g. in the same factory, are unlikely to be significant. However, in the presence of other
strong magnetic fields (from large transformers, large electrolytic cells, etc.), in situ measurements to
evaluate summation effects at medium distances (a few metres) might be appropriate. Such additional
measurements are not a requirement of this standard, but may be required by other national or
international regulations.
NOTE 2 Further guidance may be found in EN 50499 [7].
As there are different limits for general public or occupational exposure, the equipment documentation
shall clearly state the intended use.
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4.2 Equipment for use by the general public
The manufacturer shall specify if the equipment is intended to be used by the general public. Arc
welding equipment built in accordance with to EN 60974-6 shall be assessed for such use. Any
equipment assessed for general public use may also be used in an occupational environment.
If the environment in which the equipment is intended to be used is unknown, or not clear, the
equipment shall be assessed for general public use.
The basis for assessment shall be the values of basic restrictions or reference levels from the
Recommendation 1999/519/EC [2]. It must be noted that the tables of values referred to in the
following sections are explained and rationalised in the text of the Recommendation 1999/519/EC [2]
and the associated notes adjoining the tables. The basic restrictions on the current density only apply
to central nervous system tissues in the head and trunk. These exposure limit values may permit
higher current densities in body tissues other than the central nervous system under the same
exposure conditions.
4.3 Equipment for occupational use
The manufacturer shall specify if the equipment is intended to be used only in an occupational
environment (where the general public access is prohibited or regulated in such a way as to be similar
to occupational use) by an expert or an instructed person. Arc welding equipment built in accordance
with EN 60974-1 and resistance welding equipment can be assessed for such use.
The basis for assessment shall be the exposure limit values or action values from
Directive 2004/40/EC [3]. It must be noted that the tables of values referred to in the following sections
are explained and rationalised in the text of the Directive 2004/40/EC [3] and the associated notes
adjoining the tables. The exposure limit values on the current density only apply to central nervous
system tissues in the head and trunk. These exposure limit values may permit higher current densities
in body tissues other than the central nervous system under the same exposure conditions.
If the limits specified above can not be complied with for some or all points of investigation, additional
measures shall be defined which allow compliance (e.g. definition of a compliance boundary for
occupational exposure, the use of protection devices, restrictions for manual use, etc.). If such special
conditions are established, they shall be clearly stated in the instruction manual.
4.4 Equipment for occupational use in a public area
If equipment could be used under occupational conditions, but in an area where also the general
public may be exposed, then the exposure shall additionally be assessed against the general public
requirements under the conditions expected for that exposure situation (e.g. at usual safety distances)
or, alternatively, the conditions necessary for compliance shall be established during assessment.
If special conditions (such as the definition of a compliance boundary for the general public) are
established, these shall be clearly stated in the instruction manual.
4.5 Exposure of persons wearing cardiac pacemakers or other medical implants
As the immunity of different types of pacemakers or other implants varies considerably, a risk
assessment involving a responsible medical expert is necessary for every single case of user
exposure. This risk assessment is not within the scope of this product family standard. A warning
statement regarding this matter shall be included in the instruction manual.
4.6 Projectile risk
The projectile risk from ferromagnetic objects in static magnetic fields shall be considered in the
instruction manual if there is a magnetic flux density greater than 3 mT.
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4.7 Touch currents
The risk of touch currents generated by voltages induced in conducting structures at the workplace by
electromagnetic fields due to the welding current is avoided by the application of general safety rules
for electric welding, e.g. equipotential bonding and other measures, therefore no further evaluation is
required.
5 Compliance assessment
5.1 General
5.1.1 Measurement and calculation
The measurements and/or calculations to demonstrate equipment compliance shall be made in
accordance with the basic standards EN 50444 and EN 50505.
5.1.2 Time averaging
For occupational exposure the d.c. components of the magnetic flux density or field strength values
should be averaged over a time interval of 8 h, taking into account the duty cycle of the equipment and
the welding current sequence, as applicable [4].
For exposure to time-varying magnetic fields up to 10 MHz no averaging of induced current densities
over time intervals is allowed.
At frequencies below 100 kHz no averaging is allowed for H and B values, at frequencies between
100 kHz and 10 GHz averaging over any six-minute period is permissible, provided that the peak
restrictions given in the notes to Table 2 of Recommendation 1999/519/EC [2] and Table 2 of
Directive 2004/40/EC [3] are not exceeded.
5.1.3 Spatial averaging
Generally the reference levels are intended to be spatially averaged values over the entire body of the
exposed individual, but with the important proviso that the basic restrictions on localized exposure are
not exceeded.
This product family standard is used to assess mainly the exposure generated from the welding circuit,
creating stimulation effects. The maximum exposure is localized on the part of the body nearest to the
source. In this type of situation an approach based on the spatial averaging of non uniform field
distributions underestimates the exposure and is not suitable to ensure that the localized exposure
does not lead to exceeding the basic restrictions for induced current densities.
Therefore spatial averaging shall not be applied to reference level based exposure assessment of
stimulation effects due to fields generated by the welding circuit.
For evaluation of exposure generated from sources other than the welding circuit (for example from
microprocessors, radio communication systems, ancillary equipment) and assessment of thermal
effects, spatial averaging of the field may be appropriate.
2
For homogeneous models, induced current density values shall be averaged over any area of 1 cm .
In the case of induced current density values obtained by numerical simulation using high resolution
anatomic body models this area shall be limited to central nervous system tissues and shall not
include other types of tissue. Therefore the resulting averaging area for heterogeneous models shall
2
be smaller than or equal to 1 cm . For all 3D models the averaging area shall be perpendicular to the
induced current flow.
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5.1.4 Assessment of equipment with pulsed or non-sinusoidal welding current
Assessment shall be made in accordance with the basic standards EN 50444 and EN 50505.
If summation procedures are applied, the parameters given in Table 1 shall be used, as applicable.
Table 1 – Summation parameters
ƒ ƒ b d
ϕ below ƒ ϕ above ƒ coc sco
I coc I coc
Hz kHz
RAD RAD
for B & H for J for B & H for J for B & H for J for B & H for H for B for H for B
-1 -1
A m µT A m µT
General public
pi/2 0 0 -pi/2 800 1 000 150 5,2 6,25 0,73/ƒ 0,92/ƒ
exposure
Occupational
pi/2 0 0 -pi/2 820 1 000 65 24,4 30,7 – –
exposure
where
ϕ is the phase angle of the weighting function;
i
is the cut off frequency of the modelled (e.g. by RC circuit) frequency response of nervous cells;
ƒ
coc
ƒ is the summation cut off frequency;
sco
b is the value to relate frequency components above ƒ to for stimulation considerations;
sco
d is the value to relate frequency components below ƒ to for thermal considerations;
sco
ƒ is the frequency of the spectral component to be summed, given in MHz.
NOTE These values are taken from the Recommendation 1999/519/EC [2] and ICNIRP documents [5] and [6].
Alternatively the limits, reference levels and phases of the weighting functions for summation of
spectral components can be approximated by first order filters, as specified in documents defining
procedures to assess non-sinusoidal and pulsed signals [6]. Details and examples are given in the
basic standards EN 50444 and EN 50505. The first order filter approach is applicable to both
analytical and numerical methods as well as for field measurements.
5.1.5 Assessment of equipment with multiple welding current waveforms
This type of equipment shall be evaluated in all relevant operation modes, e.g. arc welding equipment
such as a MIG standard / pulse power source with constant d.c. and pulsed output current or an a.c. /
d.c. MMA power source with constant d.c. and a.c. output current. The selection of relevant operation
modes, as far as applicable, and test parameters shall be made in accordance with the basic
standards EN 50444 and EN 50505.
5.2 Assessment of EMF
5.2.1 General considerations
The EMF shall be assessed using one of the following methods. It is not necessary to demonstrate
compliance using more than one method. However, if multiple operation modes have to be tested,
different methods may be applied for these modes, e.g. measurements to show compliance with
reference levels for d.c. mode and numerical simulation to show compliance with the basic restrictions
for pulsed mode.
Selection criteria for appropriate application of assessment methods are given in the basic standards
EN 50444 and EN 50505.
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SIST EN 50445:2008
EN 50445:2008 – 10 –
5.2.2 Electric field
In general, electric fields around electric welding equipment shall be taken into account. However, for
most equipment the electric field strength can be considered to comply, without testing. This shall be
verified by analysis of the technology used.
If, by this analysis, electric fields are found to be significant, tests in accordance with generic
standards or to the manufacturers own specifications shall be made.
5.2.3 Magnetic field measurements to show compliance with reference levels
Measurements shall be made in accordance with the basic standards EN 50444 and EN 50505.
For general public exposure, the basis for assessment of static and time-varying fields shall be the
values provided in Table 2 of Recommendation 1999/519/EC [2].
For occupational exposure, the basis for assessment of static and time-varying fields shall be the
values provided in Table 2 of Directive 2004/40/EC [3].
5.2.4 Calculations to show compliance with reference levels
Analytical and numerical calculations shall be based on welding current parameters and other data
(e.g. equipment configuration and geometries). Assessment shall be made in accordance with the
basic standards EN 50444 and EN 50505.
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