IEC_60479-1_TS_64_1302_CD.pdf

64/1302/CDCOMMITTEE DRAFT(CD)IEC/TC or SC:TC 64Project numberIEC 60479-1,TS,Ed.4.0Title of TC/SC:Electrical installations and protection againstelectrical shockDate of circulation2003-05-30Closing date for comments2003-09-05Also of interest to the following committeessee below*)Supersedes document64/1257/MCRFunctions concerned:Safety EMC Environment Quality assuranceSecretary:Mr.R.Pelta(Germany)E-mail:reinhard.peltaerls.siemens.deTHIS DOCUMENT IS STILL UNDER STUDY AND SUBJECT TOCHANGE.IT SHOULD NOT BE USED FOR REFERENCE PURPOSES.RECIPIENTS OF THIS DOCUMENT ARE INVITED TO SUBMIT,WITHTHEIR COMMENTS,NOTIFICATION OF ANY RELEVANT PATENTRIGHTS OF WHICH THEY ARE AWARE AND TO PROVIDESUPPORTING DOCUMENTATION.Title:IEC 60479-1,TS,Ed.4:Effects of current on human beings and livestock-Part 1:General aspects(Titre):Introductory noteThis draft has been prepared by TC 64/WG 4.It is intended to be issued as Technical Specification.IEC 60479-1 has a status of a Basic Safety Publication(BSP).*)This publication maybe of interest for all IEC technical committees dealing with protection againstelectric shock.ACOS,TC 1,TC 16,SC 17B,SC 17D,TC 18,TC 23,SC 23E,SC 32C,SC 34D,SC 37A,TC 44,TC 61,TC 66,SC 77B,TC 81,TC 82,TC 92,TC 96,TC 99,TC 108,TC 109FORM CD(IEC)2002-05-14Copyright 2003 International Electrotechnical Commission,IEC.All rights reserved.It ispermitted to download this electronic file,to make a copy and to print out the content for the solepurpose of preparing National Committee positions.You may not copy or mirror the file orprinted version of the document,or any part of it,for any other purpose without permission inwriting from IEC.IEC 60479-1 IEC:2003 2 64/1302/CDCONTENTS1Scope and object.42Normative reference.43Definitions.53.1General definitions.53.1.1longitudinal current:Current flowing lengthwise through the trunk of thehuman body such as from hand to feet.53.1.2transverse current:Current flowing across the trunk of the human body suchas from hand to hand.53.1.3internal impedance of the human body(Zi):Impedance between twoelectrodes in contact with two parts of the human body,neglecting skinimpedances.53.1.4impedance of the skin(Zs):Impedance between an electrode on the skinand the conductive tissues underneath.53.1.5total impedance of the human body(ZT):Vectorial sum of the internalimpedance and the impedances of the skin(see figure 1).53.1.6initial resistance of the human body(RO):Resistance limiting the peak valueof the current at the moment when the touch voltage occurs.53.1.7dry condition:Condition of the skin of a surface area of contact with regardto humidity of a living person being at rest under normal indoorenvironmental conditions.53.1.8waterwet condition:Condition of the skin of a surface area of contact beingexposed for one minute to water of public water supplies(average resistivity =3500 cm,pH=7 to-9).53.1.9saltwet condition:Condition of the skin of a surface area of contact beingexposed for one minute to a 3%solution of NaCl in water(averageresistivity =30 cm,pH=7 to 9).53.1.10 deviation factor FD:is the total body impedance ZT for a given percentilerank of a population divided by the total body impedance ZT for a percentilerank of 50%of a population at a given touch voltage.53.2Effects of sinusoidal alternating current in the range 15 Hz to 100 Hz.53.2.1threshold of perception:Minimum value of current which causes anysensation for the person through which it is flowing.53.2.2threshold of reaction:Minimum value of current which causes involuntarymuscular contraction.53.2.3threshold of let-go:Maximum value of current at which a person holdingelectrodes can let go of the electrodes.53.2.4threshold of ventricular fibrillation:Minimum value of current through thebody which causes ventricular fibrillation.53.2.5heart-current factor F:Relates the electric field strength(current density)inthe heart for a given current path to the electric field strength(currentdensity)in the heart for a current of equal magnitude flowing from left handto feet.53.2.6vulnerable period:Covers a comparatively small part of the cardiac cycleduring which the heart fibres are in an inhomogeneous state of excitabilityand ventricular fibrillation occurs if they are excited by an electric current ofsufficient magnitude.63.3Effects of direct current.63.3.1total body resistance(RT):Sum of the internal resistance and theresistances of the skin.63.3.2d.c./a.c.equivalence factor(k):Ratio of direct current to its equivalent r.m.s.value of alternating current having the same probability of inducingventricular fibrillation.63.3.3upward current:Direct current through the human body for which the feetrepresent the positive polarity.6IEC 60479-1 IEC:2003 3 64/1302/CD3.3.4downward current:Direct current through the human body for which the feetrepresent the negative polarity.64Electrical impedance of the human body.64.1Internal impedance of the human body(Zi).64.2Impedance of the skin(Zs).74.3Total impedance of the human body(ZT).74.4Initial r