Iec 60990 2016

This stan ard was initial y pre ared u der the b sic safety fu ction as ig ed to TC 7 now TC 10 , as fol ows: Method of me s rin le k ge c r ent This in lu es, for variou typ s of EQUIPM

Methods of measurement of touch cur ent and protective conductor cur ent

Méthodes de mesure du courant de contact et du courant dans le conducteur de

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Methods of measurement of touch cur ent and protective conductor cur ent

Méthodes de mesure du courant de contact et du courant dans le conducteur de

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CONTENTS

FOREWORD 6

INTRODUCTION 8

1 Sco e 10 2 Normative referen es 10 3 Terms an definition 11 4 Test site 11 4.1 Test site en ironment 11 4.2 Test tran former 12 4.3 Earthed neutral con u tor 12 5 Me s rin eq ipment 13 5.1 Selection of me s rin network 13 5.1.1 General 13 5.1.2 Perce tion an startle-re ction 14 5.1.3 L tgo-immo i zation 14 5.1.4 Electric burn (a.c.) 14 5.1.5 Rip le- re d.c 14 5.2 Test electrodes 15 5.2.1 Con tru tion 15 5.2.2 Con ection 15 5.3 Config ration 15 5.4 Power con ection d rin test 15 5.4.1 General 15 5.4.2 Eq ipment for u e only on TN or TT star p wer distribution s stems 19 5.4.3 Eq ipment for u e on IT p wer distribution s stems in lu in u e rthed delta s stems 19 5.4.4 Eq ipment for u e on sin le-phase centre-e rthed p wer s p ly s stems or on centre-e rthed delta p wer s p ly s stems 2

5.5 Sup ly voltage an freq en y 2

5.5.1 Sup ly voltage 20 5.5.2 Sup ly freq en y 2

6 Test proced re 2

6.1 General 2

6.1.1 Touc c r ent me s rements 2

6.1.2 Control switc es, eq ipment an s p ly con ition 21

6.1.3 Use of me s rin networks 21

6.2 Normal an fault con ition of eq ipment 21

6.2.1 Normal o eration of eq ipment 21

6.2.2 Eq ipment an s p ly fault con ition 21

7 Evaluation of res lts 2

7.1 Perce tion, startle-re ction an letgo-immo i zation 2

7.2 Electric burn 2

8 Me s rement of protective con u tor c r ent 2

8.1 General 2

8.2 Multiple eq ipment 2

8.3 Me s rin method 2

An ex A (normative) Eq ipment 2

An ex B (normative) Use of a con u tive plane 2

An ex C (normative) In idental y con ected p rts 2

An ex D (informative) Choice of c r ent l mits 2

D.1 General 2

D.2 Limit examples 2

D.2.1 Ventric lar fibri ation 2

D.2.2 Ina i ty to letgo-immo i zation 2

D.2.3 Startle-re ction 28 D.2.4 Perce tion thres old 2

D.2.5 Sp cial a pl cation 2

D.3 Choice of l mits 2

D.4 Electric burn ef ects of tou h c r ent 3

An ex E (informative) Networks for u e in me s rement of tou h c r ent 31

E.1 General 31

E.2 Bod imp dan e network – Fig re 3 31

E.3 Startle-re ction (an b d imp dan e) network – Fig re 4 31

E 4 L tgo-immo i zation (an b d imp dan e) network – Fig re 5 3

An ex F (informative) Me s rin network l mitation an con tru tion 3

An ex G (informative) Con tru tion an a pl cation of tou h c r ent me s rin in truments 3

G.1 Con ideration for selection of comp nents 3

G.1.1 General 35 G.1.2 Power ratin an in u tan e for R S an R B 3

G.1.3 Ca acitor C S 3

G.1.4 Resistors R1, R2 an R3 3

G.1 5 Ca acitors C1, C2 an C3 3

G.2 Voltmeter 3

G.3 Ac urac 3

G.4 Cal bration an a pl cation of me s rin in truments 3

G.5 Record 3

G.6 Confirmation s stems 3

An ex H (informative) Analy is of freq en y fi tered tou h c r ent circ it me s rements 3

An ex I (informative) AC p wer distribution s stems (se 5.4) 47 I 1 General 4

I 2 TN p wer s stems 4

I 3 TT p wer s stems 50 I 4 IT p wer s stems 51

An ex J (informative) Routine an p riodic tou h c r ent tests, an tests afer re air or modification of main o erated eq ipment 5

An ex K (normative) Network p rforman e an cal bration 5

K.1 Network or in trument p rforman e an initial cal bration 5

K.2 Cal bration in a confirmation s stem 5

K.2.1 General 56 K.2.2 Me s rement of input resistan e 5

K.2.3 Me s rement of in trument p rforman e 5

Bibl ogra h 5

Fig re 1 – Example of e rthed neutral, direct s p ly 12

Fig re 2 – Example of e rthed neutral, with tran former for isolation 13

Fig re 3 – Me s rin network, u weig ted tou h c r ent 13

Fig re 4 – Me s rin network, tou h c r ent weig ted for p rce tion or startl

e-re ction 14

Fig re 5 – Me s rin network, tou h c r ent weig ted for letgo-immo i zation 14

Fig re 6 – Sin le-phase eq ipment on star TN or TT s stem 16

Fig re 7 – Sin le-phase eq ipment on centre-e rthed TN or T s stem 16

Fig re 8 – Sin le-phase eq ipment con ected l ne- o-l ne on star TN or TT s stem 17

Fig re 9 – Sin le-phase eq ipment con ected l ne- o-neutral on star IT s stem 17

Fig re 10 – Sin le-phase eq ipment con ected l ne- o-l ne on star IT s stem 17

Fig re 1 – Thre -phase eq ipment on star TN or TT s stem 18

Fig re 12 – Thre -phase eq ipment on star IT s stem 18

Fig re 13 – Une rthed delta s stem 19

Fig re 14 – Thre -phase eq ipment on centre-e rthed delta s stem 19

Fig re A.1 – Eq ipment 25

Fig re B.1 – Eq ipment platorm 2

Fig re F.1 – Freq en y factor for electric burn 3

Fig re F.2 – Freq en y factor for perce tion or startle-re ction 3

Fig re F.3 – Freq en y factor for letgo-immo i zation 3

Fig re H.1 – Trian ular waveform tou h c r ent, startle-re ction 4

Fig re H.3 – 1 ms rise time pulse resp n e, startle-re ction 41

Fig re H.4 – 1 ms rise time pulse resp n e, letgo-immo i zation 41

Fig re H.5 – Tou h c r ent v rise time plot, 2 ms s uare wave 4

Fig re H.6 – PFC SMPS tou h c r ent waveform 4

Fig re H.7 – 5 Hz s uare wave, 0,1 ms rise time, startle-re ction 43 Fig re H.8 – 5 Hz s uare wave, 0,1 ms rise time, letgo-immo i zation 4

Fig re H.9 – IEC TS 6 4 9-2 let go thres old for AC an DC combination au mented by ad itional data, mA e c axis 4

Fig re H.10 – Ex1 case: s owin r.m.s win ow 4

Fig re H.1 – Waveform ex2 case: s owin r.m.s win ow 4

Fig re I 1 – Examples of TN-S p wer s stem 4

Fig re I 2 – Example of TN-C-S p wer s stem 4

Fig re I 3 – Example of TN-C p wer s stem 4

Fig re I 4 – Example of sin le-phase, 3-wire TN-C p wer s stem 5

Fig re I 5 – Example of 3-l ne an neutral TT p wer s stem 50 Fig re I 6 – Example of 3-l ne TT p wer s stem 51

Fig re I 7 – Example of 3-l ne (an neutral) IT p wer s stem 51

Fig re I 8 – Example of 3-l ne IT p wer s stem 5

Ta le H.1 – Trian ular waveform resp n e comp rison 4

Ta le H.2 – Sq are wave tou h c r ent resp n e 41

Ta le H.3 – Sq are wave mono olar tou h c r ent resp n e 4

Ta le H.4 – Mixed ACnDC waveform evaluation, ex1 4

Ta le H.5 – Mixed ACnDC waveform evaluation, ex2 4

Ta le K.1 – Calc lated input imp dan e an tran fer imp dan e for u weig ted tou h

c r ent me s rin network (Fig re 3) 5

Ta le K.2 – Calc lated input impedan e an tran fer imp dan e for startle-re ction

tou h c r ent me s rin network (Fig re 4) 5

Ta le K.3 – Calc lated input imp dan e an tran fer imp dan e for letg

o-immo i zation c r ent me s rin network (Fig re 5) 5

Ta le K.4 – Output voltage to input voltage ratios for u weig ted tou h c r ent

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International Stan ard IEC 6 99 has b en pre ared by TC 10 : Safety of electronic

eq ipment within the field of au io/vide , information tec nolog an commu ication

tec nolog

This third edition can els and re laces the secon edition publs ed in 19 9 It con titutes a

tec nical revision

The prin ip l c an es in this edition as comp red with the secon edition are as fol ows:

– the efects names have b en updated to reflect in re sed u derstan in of the ran e of

efects an is in con ert with present u age;

– the con ition of u e in o in a GRIP ABLE PA T have b en red ced in the a pl cation of

the req irements based up n the c r ent u derstan in of this ef ect;

– the referen es to ISO 10 12-1, whic has b en re laced by management stan ard of the

same n mb r, have b en re laced with explanatory text, where ne ded to maintain the

sen e of the doc ment;

– former informative An ex H (GRIP ABLE PA T) has b en deleted from this update as it

do s not pro erly re resent the ful set of con ition u der whic immo i zation can

oc ur A new informative An ex H (Analy is of freq en y fi tered tou h c r ent circ its

Ful information on the votin for the a proval of this stan ard can b fou d in the re ort on

votin in icated in the a ove ta le

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– notes/explanatory mat er: in smaler roma ty e;

–

normative con ition within ta les:

in smaler roma ty e;

– terms defined in Clau e 3: SMAL C PITALS

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INTRODUCTION

This International Stan ard was develo ed as a resp n e to con ern arisin from the ad ent

of electronic switc in tec niq es b in bro dly a pl ed to p wer s stems an within

EQUIPMENT, givin rise to hig - req en y harmonic voltages an c r ents

This stan ard is inten ed for the g idan e of EQUIPMENT commit e s in pre arin or

amen in the test sp cification in their stan ard for me s rement of le k ge c r ent

However the term "le k ge c r ent" is not u ed for re son explained b low

This stan ard was initial y pre ared u der the b sic safety fu ction as ig ed to TC 7 (now

TC 10 ), as fol ows:

Method of me s rin le k ge c r ent

This in lu es, for variou typ s of EQUIPMENT, al asp cts of what is refer ed to as "le k ge

c r ent", in lu in method of me s rement of c r ent with regard to ph siological ef ects

an for in tal ation purp ses, u der normal con ition an u der certain fault con ition

The method of me s rement of le k ge c r ent des rib d herein res lt from the review of

IEC TS 6 4 9-1 an other publ cation , in lu in des ription of e rler method of

me s rement

The fol owin con lu ion were derived from a review of the efects of le k ge c r ent:

– the primary con ern for safety in olves p s ible flow of harmful c r ent throu h the

h man b d ( his c r ent is not neces ari y eq al to the c r ent flowin throu h a

protective con u tor);

– the efect of electric c r ent on a h man b d is fou d to b somewhat more complex

than was as umed d rin the develo ment of e rler stan ard in that there are several

b d resp n es whic s ould b con idered The most sig ificant resp n es for set in

l mits for contin ou waveforms are

• p rce tion,

• startle-re ction,

• letgo-immo i zation, an

• ELECTRIC BU N

Eac of these four b d resp n es has a u iq e thres old level There are also sig ificant

dif eren es in the man er in whic some of these thres old vary with freq en y

Two typ s of c r ent have b en identified as ne din se arate me s rin method : TOU H

CU RENT an

PROT CTIVE CON U TOR C R EN

T

TOU H C RRENT only exists when a h man b d or a b d model is a c r ent p thway

It was also noted that the term "le k ge c r ent" has alre d b en a pl ed to several diferent

con ern : TOU H C R ENT, PROT CTIVE CON U TOR C RRENT, in ulation pro erties, etc

Therefore, in this stan ard, the term "le k ge c r ent" is not used

Me s rement of TOUC C R ENT

In the p st, EQUIPMENT stan ard have u ed two traditional tec niq es for me s rement of

le k ge c r ent Either the actual c r ent in the protective con u tor was me s red, or a

simple resistor-ca acitor network (re resentin a simple b d model) was u ed, the le k ge

c r ent b in defined as the c r ent throu h the resistor

This stan ard provides me s rin method for the four b d resp n es to the electric c r ent

noted a ove, u in a more re resentative b d model

This b d model was c osen for most common cases of electric s ock in the general sen e

With resp ct to the p th of c r ent flow an con ition of contact, a b d model

a proximatin ful han - o-han or han - o- o t contact in normal con ition is u ed For

smal are s of contact ( or example, smal, fin er contact , a dif erent model may b

a pro riate but is not covered here

Of the four resp n es, startle-re ction an letgo-immo i zation are related to the p a value

of TOU H C R ENT an vary with freq en y Traditional y, con ern for electric s ock have

de lt with sin soidal waveforms, for whic r.m.s me s rements are most con enient Pe k

me s rements are more a pro riate for non-sin soidal waveforms where sig ificant values

of TOU H CU RENT are exp cted, but are eq al y s ita le for sin soidal waveforms The

networks sp cified for the me s rement of startle-re ction an letgo-immo i zation are

freq en y-resp n ive an are so weig ted that sin le l mit p wer- req en y values can b

specified an referen ed

ELECTRIC BU NS, however, are related to the r.m.s value of TOU H C R ENT, an are relatively

in e en ent of freq en y For EQUIPMENT where ELECTRIC BU NS may b of con ern (se

7.2), two se arate me s rements are made, one in p a value for electric s ock an a

secon in r.m.s value for ELECTRIC BU NS e c u in the a pro riate test circ it

EQUIPMENT commit e s s ould decide whic ph siological efects are ac e ta le an whic

are not, an then decide on lmit values of c r ent Commit e s for certain typ s of EQUIPMENT

may ado t simplfied proced res b sed up n this stan ard A dis u sion of l mit values,

b sed up n e rl er work by variou IEC EQUIPMENT commit e s, is provided in Annex D

Me s rement of PROT CTIVE COND CTOR C R ENT

In certain cases, me s rement of the PROT CTIVE CON U TOR CU RENT of EQUIPMENT u der

normal o eratin con ition is req ired Su h cases inclu e:

– selection of a resid al c r ent protection device,

– determination when a hig integrity protective e rth circ it is req ired,

– prevent ex es ive PROT CTIVE COND CTOR C R ENT overlo d in the electrical in tal ation

The PROT CTIVE CON UCTOR C RRENT is me s red by in ertin an ammeter of negl gible

imp dan e in series with the EQUIPMENT protective e rthin con u tor

METHODS OF MEASUREMENT OF TOUCH CURRENT

AND PROTECTIVE CONDUCTOR CURRENT

This International Stan ard defines me s rement method for

– d.c or a.c c r ent of sin soidal or non-sin soidal waveform, whic could flow throu h the

h man b d , an

– c r ent flowin throu h a protective con u tor

The me s rin method recommen ed for TOU H C RRENT are b sed up n the pos ible

ef ects of c r ent flowin throu h a h man b d In this stan ard, me s rements of c r ent

throu h networks re resentin the imp dan e of the h man b d are refer ed to as

me s rements of TOU H C R ENT These networks are not neces ari y val d for the b dies of

animals

The sp cification or impl cation of sp cific l mit values is not within the s o e of this stan ard

IEC TS 6 4 9 series provides information regardin the efects of c r ent p s in throu h

the h man b d from whic l mit values may b derived

This stan ard is a pl ca le to al clas es of EQUIPMENT, ac ordin to IEC 61 4

The method of me s rement in this stan ard are not inten ed to b u ed for

– TOU H CU RENT havin les than 1 s d ration,

– p tient c r ents as defined in IEC 6 6 1-1,

– a.c at freq en ies b low 15 Hz, an

– c r ents a ove those c osen for ELECTRIC BU N l mits

This b sic safety publ cation is primari y inten ed for u e by tec nical commit e s in the

pre aration of stan ard in ac ordan e with the prin iples laid down in IEC Guide 10 an

ISO/IEC Guide 51 It is not inten ed for u e by man facturers or certification b dies

in e en ent of prod ct stan ard

One of the resp n ibi ties of a tec nical commite is, wherever a pl ca le, to ma e u e of

b sic safety publcation in the pre aration of its publ cation The req irements, test

method or test con ition of this b sic safety publ cation only a ply when sp cifical y

refer ed to or in lu ed in the relevant publ cation

2 Normative references

The fol owin doc ments, in whole or in p rt, are normatively referen ed in this doc ment

an are in isp n a le for its a pl cation For dated referen es, only the edition cited a pl es

For u dated referen es, the latest edition of the referen ed doc ment (in lu in an

IEC 61 4 , Protecto against electric sh ck – Commo asp cts for instalato a d

e u ipme t

ISO/IEC Guide 51:2 14, Safety asp cts – G uideln s forth ir inclu sio in sta dards

IEC Guide 10 :2 10, Th pre arato of safety pub licato s a d th u se of b asic safety

p u b licato s a d grou p safety p u b licato s

3 Terms and definitions

For the purp ses of this doc ment, the fol owin terms an definition a ply

3.1

TOU H C RRENT

electric c r ent throu h a h man b d or throu h an animal b d when it tou hes one or

more ac es ible p rts of an in tal ation or of EQUIPMENT

[SOURCE: IEC 6 0 0-19 :19 8, 19 -0 -21]

3.2

P OT CTIVE CON U TOR C R ENT

c r ent whic flows in a protective con u tor

3.3

EQUIPMENT

organized col ection of electromec anical comp nent p rts an fe tures to ac ompl s a

defined task (as sp cified in the relevant prod ct stan ard)

Note 1 to e try: If n t sp cifie in th rele a t sta d rd, se An e A

Test site en ironmental req irements s al b as sp cified in the EQUIPMENT stan ard If l mit

values of les than 7 µA r.m.s or 10 µA p a are sp cified, or if the EQUIPMENT contain

large s ield whic may b driven by hig - req en y sig als, prod ct commit e s s al refer

to An ex B

4.2 Te t tra sformer

The u e of a test tran former for isolation is o tional For maximum safety, a test tran former

for isolation (T2 in Fig re 2, T in Fig re 6 to Fig re 14) s al b u ed an the main protective

e rthin terminal of the EQUIPMENT u der test (EUT) e rthed An ca acitive le k ge in the

tran former s al then b ta en into ac ou t As an alternative to e rthin the EUT, the test

tran former secon ary an the EUT s al b lef flo ting (not e rthed), in whic case the

ca acitive le k ge in the test tran former ne d not b ta en into ac ou t

If tran former T is not u ed, the EUT s al b mou ted on an in ulatin stan an a pro riate

safety precaution ta en, in view of the p s ibi ty of the b d of the EUT b in at hazardou

voltage

4.3 Earthe ne tral conductor

EQUIPMENT inten ed for con ection to a T or TN p wer distribution s stem s al b tested

with minimum voltage b twe n neutral an e rth

NOT Descriptio s of v rio s p wer distrib tio systems are giv n in An e I

The protective con u tor an the e rthed neutral con u tor for the EUT s ould have a

voltage diferen e of les than 1 % of l ne- o-l ne voltage (se example in Fig re 1)

A local tran former, se 4.2, wi ac ieve this req irement

Alternatively, if the voltage dif eren e is 1 % or more, the fol owin are examples of method

whic , in some cases, wi avoid me s rement er ors d e to this voltage:

– con ectin the terminal B electrode of the me s rin in trument network to the neutral

terminal of the EUT in te d of the protective e rthin con u tor (se 6.1.2) of the s p ly;

– con ectin the e rthin terminal of the EUT to the neutral con u tor, in te d of the

protective e rthin con u tor, of the s p ly

Figure 1 – Ex mple of e rth d ne tral dire t s pply

IEC

Fig re 2 – Ex mple of e rthe ne tral with tra sformer for isolation

5 Measuring equipment

5.1 Sele tion of me s rin network

5.1.1 Ge eral

Me s rements s al b made with one of the networks of Fig re 3, Fig re 4 an Fig re 5

NOT Se An e es E, F a d G for furth r e pla atio of th thre n tworks

NOT For sp cialc n itio s o th use of this n twork, se 5.1.2.

Figure 5 – Me s rin network, touc c r e t weighte for letgo-immobi ization

5.1.2 Perc ption a d startle-re ction

The network of Fig re 4 s al b u ed for low level electric s ock l mits This circ it is to b

a pl ed where the a.c l mit value in the prod ct stan ard is up to 2 mA r.m.s or 2,8 mA p a

5.1.3 Letgo-immobi ization

The network of Fig re 5 s al b u ed for hig er level electric s ock l mits This circ it is to

b a pl ed where the a.c l mit value in the prod ct stan ard is more than 2 mA r.m.s or

5.2 Te t ele trode

5.2.1 Construction

Unles otherwise sp cified in the EQUIPMENT stan ard, the test electrodes s al b

– a test cl p, or

– a 10 cm × 2 cm metal foi to re resent the h man han Where ad esive metal foi is

u ed, the ad esive s al b con u tive

5.2.2 Conne tion

Test electrodes s al b con ected to test terminals A an B of the me s rin network

5.3 Configuration

The EQUIPMENT u der test (EUT) s al b ful y as embled an re d for u e in the maximum

config ration; it s al b con ected to external sig al voltages where a pl ca le, as sp cified

by the man facturer for a sin le EQUIPMENT

EQUIPMENT whic is desig ed for multiple p wer sources, only one of whic is req ired at a

time ( or example, for b ckup), s al b tested with only one source con ected

EQUIPMENT req irin p wer simultane u ly from two or more p wer sources s al b tested

with al p wer sources con ected but with not more than one con ection to protective e rth

5.4 Power conne tions durin te t

5.4.1 Ge eral

NOT Ex mples of p wer distrib tio systems are giv n in An e I

EQUIPMENT s al b con ected in a test config ration as s own in Fig re 6 to Fig re 14,

ac ordin to 5.4.2, 5.4.3 or 5.4.4, as a pro riate

EQUIPMENT commite s s ould consider the p s ible ne d for the man facturer to identify the

p wer distribution s stem (TN, TT, IT) to whic an EQUIPMENT is inten ed to b con ected in

its final a pl cation

If the EUT is sp cified by the man facturer for u e only on certain p wer distribution

s stems, the EUT s al b tested only when con ected to those s stems

EQUIPMENT to b con ected only to TN or T s stems s al comply with 5.4.2 EQUIPMENT to

b con ected to IT s stems s al comply with 5.4.3 an may also b con ected to TN or TT

s stems

For Clas 0 an Clas I EQUIPMENT (se IEC 61 4 ), the protective con u tors in Fig re 6

throu h Fig re 14 are ig ored

Figure 6 – Single-ph s e uipme t on star TN or TT s stem

Th c ntre-a p d win in ma b o e le of a d lta su ply

Figure 7 – Single-pha e e uipme t on c ntre-e rthe TN or T s stem

IEC IEC

Figure 8 – Sin le-ph s e uipme t conne te l ne-to-l ne on star TN or TT s stem

Th 1 0 0 Ω resistor sh uld b rate for su ply system fa lts

Figure 9 – Sin le-pha e e uipme t conne te l n -to-ne tral on star IT s stem

Th 1 0 0 Ω resistor sh uld b rate for su ply system fa lts

Figure 10 – Single-pha e e uipme t conne te l ne-to-l ne on star IT s stem

IEC IEC IEC

Fig re 1 – Thre -ph s e uipme t on star TN or TT s stem

Th 1 0 0 Ω resistor sh uld b rate for su ply system fa lts

Figure 12 – Thre -ph se e uipme t on star IT s stem

IEC IEC

Figure 13 – Une rthe delta s stem

Wh re a EQUIPME T c ntains b th a thre -p ase lo d a d a c ntre-e rth d sin le-p ase lo d, a d th e rth d

sid is id ntifie , switc g sh l remain in th p sitio id ntifie as th e rth d sid

Figure 14 – Thre -pha e e uipme t on c ntre-e rthe delta s stem

5.4.2 Eq ipme t for us only on TN or TT star power distribution s stems

Thre -phase EQUIPMENT s al b con ected to a thre -phase star p wer distribution s stem,

with e rthed neutral Sin le-phase EQUIPMENT s al b con ected b twe n phase an neutral

of an e rthed neutral p wer distribution s stem or, where sp cified by the man facturer to

o erate in s c a man er, l ne- o-l ne on a centre-e rthed thre -phase star p wer distribution

s stem (se Fig re 6, Fig re 8 an Fig re 1 )

5.4.3 Equipme t for us on IT power distribution s stems in ludin une rthe delta

s stems

Thre -phase EQUIPMENT s al b con ected to an a pro riate thre -phase IT p wer s p ly

s stem Sin le-phase EQUIPMENT s al b con ected b twe n phase an neutral or, where

sp cified by the man facturer to o erate in s c a man er, l ne- o-l ne (se Fig re 9,

Fig re 10, Fig re 12 an Fig re 13)

IEC IEC

5.4.4 Equipme t for us on sin le-pha e c ntre-e rthe power s p ly s stems or on

c ntre-e rthe delta power s p ly s stems

Sin le-phase EQUIPMENT s al b con ected to a s p ly havin its centre ta e rthed

Sup ly voltage s al b me s red at the EQUIPMENT s p ly terminals

Traditional y, TOU H C RRENT was at its maximum at the hig est s p ly voltage Modern

electronic p wer s p l es wi not alway provide maximum TOU H C R ENT u der this s p ly

con ition TOU H C R RENT may b maximized at the lowest voltage, i.e maximum c r ent

draw, or u der some other con ition Electric s ock protection s al b provided u der the

worst case o eratin con ition

EQUIPMENT rated for a sin le voltage s al b tested at its rated voltage plu an a pro riate

workin toleran e to al ow for s p ly variation

EQUIPMENT rated for a nominal voltage ran e s al b tested at the extremes of the voltage

ran e, plu an a pro riate workin toleran e to al ow for s p ly variation The workin

toleran e is determined by the EQUIPMENT commite or by the man facturer if neces ary ( or

example, 0 %, -10 %/+ % or +10 %)

EQUIPMENT rated for diferent nominal voltages or voltage ran es, usin a voltage selector,

s al b set for the hig est nominal voltage or voltage ran e an then tre ted as a ove

Where voltage selection in olves more complex switc in than a re r an ement of

tran former win in s, ad itional tests may b neces ary to determine the worst case

If it is in on enient to test EQUIPMENT at the sp cified voltage, it is p rmited to test it at an

avai a le voltage within the ratin of the EQUIPMENT an then calc late the res lts

5.5.2 Sup ly fre ue c

Sup ly freq en y s al b the maximum rated nominal freq en y, or alternatively,

me s rements may b cor ected by calc lation for estimation of the worst case c r ent

6 Test procedure

6.1 Ge eral

6.1.1 Touc c r e t me s reme ts

Prod ct commite s may wis to ex lu e me s rement of TOU H C RRENT at some ac es ible

p rts, b sed up n the prin iple of l mitation of voltage (se IEC 6 3 4-4-41) If so,

me s rements s al b made for ac es ible voltage an then, if req ired, for weig ted or

u weig ted TOU H C RRENT ac ordin to Clau e 6

Con ern for ELECTRIC BUR ef ects may arise with d.c or at hig freq en ies ( or example,

a ove 3 kHz for 3,5 mA TOU H C RRENT) At lower freq en ies, startle-re ction an letg

o-immo i zation wi b the dominant con ideration Where there is s c a con ern, the

u weig ted r.m.s value of TOU H C RRENT s al b me s red (Fig re 3), in ad ition to

me s rement for either startle-re ction (Fig re 4), or ina i ty to let go (Fig re 5)

6.1.2 Control switc e , e uipme t a d s pply con itions

Durin TOU H C RRENT me s rements, the test en ironment, config ration, e rthin an

s p ly s stem s al b ac ordin to 5.3, 5.4 an 5.5

In order to maximize the c r ent values d rin me s rements, the config ration s al b

varied by con ection an dis on ection of u its that are p rt of the EQUIPMENT, as p rmit ed

by the man facturer's o eratin an in tal ation in tru tion

Control switc es e, g, l, n an p in Fig re 6 to Fig re 14 s al b manipulated as des rib d in

6.2, whi e the con ition l sted in this s bclau e an 6.2.1 are in e en ently varied so as to

give the maximum meas red value or values Prod ct commite s s al ma e an a pro riate

selection of these varia les Recent ad ition of ABNORMAL OP R TION as an o eratin

con ition in prod ct stan ard as related to the electrical in tal ation (e.g the los of P or

the ina i ty to en ure p larity of s p ly) clarifies the test con ition un er NORMAL o eration

an FA LT CON ITIONS to then b a pl ed

6.1.3 Us of me s rin network

Ap ro riate me s rin electrodes (se 5.2), me s rin network (se 5.1) an me s rin

device (se G.4) s al b u ed in ac ordan e with the a pro riate s stems of Fig re 6 to

Fig re 14 (se 5.4) to ma e me s rements of TOU H CU RENT b twe n simultane u ly

ac es ible p rts, an b twe n ac es ible p rts an e rth

The terminal A electrode s al b a pled to e c ac es ible p rt in turn

For e c a pl cation of the terminal A electrode, the terminal B electrode s al b a pl ed to

e rth, then a pl ed to e c of the other ac es ible p rts in turn

For p wer s stems with an e rthed p wer con u tor, the terminal B electrode may b

con ected directly to the e rthed p wer con u tor at the interface of the EUT an the power

s p ly, in te d of b in con ected to the protective con u tor This con ection may b u ed

even thou h the voltage diferen e b twe n the protective con u tor an the e rthed p wer

con u tor is more than 1 % of the lne- o-lne voltage (se 4.2)

6.2 Normal a d fa lt conditions of e uipme t

6.2.1 Normal operation of e uipme t

The test is car ied out with terminal A of the me s rin network con ected to e c u e rthed

or con u tive ac es ible p rt an circ it in turn, with al test switc es l, n an e closed

Me s rements s al b made in al a pl ca le con ition of normal o eration

Examples of normal o eration in lu e main switc on, main switc of, stan by, start up,

he tin an an setin of o erator controls ex e t s p ly-voltage-set in controls

Sin le-phase

EQUIPMENT s al b tested in normal an reverse p larity (switc p)

Thre -phase EQUIPMENT s al b tested with phase reversals, u les EQUIPMENT o eration is

For EQUIPMENT havin a protective e rthin con ection or a fu ctional e rthin con ection,

terminal A of the me s rin network is con ected to the EQUIPMENT e rthin terminal of the

EUT

Me s rements s al b made with e c of the a pl ca le fault con ition sp cified in 6.2.2.2

to 6.2.2.9 The faults s al b a pl ed one at a time, but s al in lu e an faults whic are a

logical res lt of the first fault Before a plyin an fault, the EQUIPMENT s al b restored to its

original con ition ( or example, without faults or con eq ential damage)

Where a b lan ed l ne fi ter is u ed on thre -phase EQUIPMENT, the net c r ent to e rth is

the retical y zero However, it is normal for comp nent an voltage u b lan e to prod ce a

finite value of net c r ent, the maximum value of whic may not b me s red d rin typ

testin L rger u b lan ed c r ents wi res lt from a fai ed ca acitor in one phase

EQUIPMENT commite s s ould con ider in lu in a test for s c EQUIPMENT, in olvin the

s bstitution of a del b rately faulted fi ter (one ca acitor removed), together with a los of

protective e rth con ection (se 6.2.2.2)

Simi ar con ideration a ply to a b lan ed ar an ement of other comp nents, s c as s rge

ar estors, con ected b twe n main an e rth

Thre -phase EQUIPMENT s al b tested with phase reversals u les EQUIPMENT o eration is

de en ent on phasin

6.2.2.2 Fa lt condition No 1

De en in on the kin of EQUIPMENT, several safety degre s of the protective con u tor are

to b disting is ed (se IEC 61 4 )

Sin le-phase EQUIPMENT not rel a ly e rthed s al b tested with los of protective e rth

connection (switc e) in combination with normal an reverse p larity (switc p)

Thre -phase EQUIPMENT not rela ly e rthed s al b tested with los of protective e rth

connection (switc e)

Unles decided otherwise by the prod ct commit e , the req irements of this s bclau e do

not a ply to rel a ly e rthed EQUIPMENT whic is con ected to the s p ly either p rmanently,

or by mean of plu s an sock ts whic are of in u trial grade ( or example, con ectors

specified in IEC 6 3 9-1 or a comp ra le national stan ard)

6.2.2.3 Fa lt condition No 2

Sin le-phase EQUIPMENT s al b tested with neutral o en (switc n), with e rth intact an in

normal p larity, an again in reverse p larity (switc p)

Sin le-phase EQUIPMENT for u e on IT p wer s stems or on thre -phase delta s stems s al

b tested with a thre -phase p wer s stem, with e c phase faulted to e rth, one at a time

(switc g), in combination with normal an reverse p larity (switc p) an se arately with

e c phase con u tor o en one at a time (switc es l), an in combination with normal an

reverse p larity (switc p)

6.2.2.7 Fa lt condition No 6

Thre -phase EQUIPMENT for u e on centre-e rthed delta s p ly s stems s al b tested on a

delta s p ly s stem with e c delta-leg centre-e rthed, one at a time (switc g)

EQUIPMENT containin b th thre -phase an centre-e rthed circ its whic can ot b in tal ed

in e en ently an whic have an identified e rthed leg s al b tested with switc g on the

Ac es ible con u tive p rts whic are only in idental y electrical y con ected to other p rts

s al b tested b th when con ected electrical y to the other p rt s) an when dis on ected

electrical y from the other p rt s) Se An ex C regardin in idental y con ected p rts

a sin le, low- req en y eq ivalent in ication of TOU H C RRENT res lts for al freq en ies

present a ove 15 Hz These weig ted values of TOU H CU RENT are ta en as the hig est

maximum values are comp red with the l mits for p rce tion or startle-re ction an letg

o-immo i zation sp cified for the EQUIPMENT ( or example, a 5 Hz or 6 Hz lmit value)

Me s rements for d.c l mits are made in a l k man er, but ta en as U

1

divided by 5 0 Ω

(se also An ex G)

7.2 Ele tric burn

Where there is con ern for ELECTRIC BUR efects (se 6.1), the u weig ted r.m.s or d.c

value of TOU H C RRENT is me s red This is calc lated from the r.m.s voltage U

1, me s red

acros the 5 0 Ω resistor of the me s rin network of Fig re 3

The ef ect of TOU H C R ENT is also related to the are of contact with the h man b d an

the d ration of contact The relation hip b twe n these p rameters an the esta l s ment of

TOU H C RRE

NT lmits are not in the s o e of this stan ard (se also Clau e D.3)

NOT ELECTRIC B RN result from th p wer dis ip te as c r e t flows thro g th resista c of th h ma skin

a d b d Oth r forms of b rn c n result from ele tric l EQUIPME T, for e ample d e to arcin or th b -pro u ts

of arcin

8 Measureme t of protective conductor cur ent

8.1 Ge eral

Cur ent req irements an values for protective con u tors are not related to TOUC C RRENT

con ern an , therefore, s c l mits an method of me s rement are de lt with se arately

8.2 Multiple e uipme t

Within an s ared e rthin s stem, the PROT CTIVE CON U TOR C R ENT of in ivid al

EQUIPMENT combine in a non-arithmetic man er Therefore, THE PROT CTIVE CON U TOR

CU RENT of a group OF EQUIPMENT e rthed by a sin le protective e rthin con u tor can ot

b rel a ly predicted from knowled e of in ivid al EQUIPMENT PROT CTIVE CON U TOR

CU RENT Con eq ently, me s rements made on in ivid al EQUIPMENT are of l mited u e,

an the PROT CTIVE COND CTOR C R ENT for that group of EQUIPMENT s al b me s red in

the s ared protective e rthin con u tor

8.3 Me s ring method

The in tal ation PROT CTIVE CON UCTOR C R ENT s al b me s red af er in tal ation by

in ertin an ammeter of negl gible imp dan e ( or example, 0,5 Ω) in series with the

protective con u tor Me s rement of PROT CTIVE CON U TOR CU RENT is made with the

EQUIPMENT an p wer distribution s stem ru nin in al normal o eratin modes

Annex A

(normativ )

Equipment

Unles otherwise defined in the EQUIPMENT stan ard, an EQUIPMENT is identified as havin a

sin le con ection to a s p ly of electricity

An EQUIPMENT may b a sin le u it or may con ist of ph sical y se arate, electrical y

intercon ected u its (se Fig re A.1) The source of electricity may b contained within the

EQUIPMENT ( or example, solar or b tery p wer)

The con ection of sig al ca les s al b con idered as p rt of the EQUIPMENT, in ac ordance

with 5.4

Ke

Su ply c n e tio c mp tible with lo al su ply

Su ply c n e tio n t d sig e to b c n e te dire tly to lo al su ply

Oth r c n e tio s

Figure A.1 – Eq ipme t

IEC

Annex B

(normativ )

Use of a conductive plane

Where l mits for TOU H CU RENT (with or without freq en y weig tin ) les than 7 µA r.m.s

or 10 µA p a are sp cified, or where an EQUIPMENT is tested that has large ca acitive

coupln to outer s rfaces whic may b driven at hig freq en ies ( or example, hig

-freq en y sig al generators an voltage me s rin in truments), it is a pro riate to me s re

the c r ent whic is coupled ca acitively into a con u tive s rface placed b ne th or again t

a s rface of the EQUIPMENT If the EQUIPMENT is to b tested in this man er, it s al b placed

on a con u tive plane whic is in turn placed on an in ulatin s rface (se Fig re B.1)

The con u tive plane s al b eq al to or gre ter than the adjacent EQUIPMENT s rface in

are an p rimeter

Me s rements s al b ac ordin to Clau e 6, with the con u tive plane tested as an

ac es ible p rt

The me s rements s al b re e ted with the con u tive plane placed again t an other

s rface of the EQUIPMENT whic may b come adjacent to an outside con u tive plane

For purp ses of isolation from electromag etic interferen e, it may b neces ary to place the

EQUIPMENT (in lu in the con u tive plane, if used) 0,5 m or more from other con u tors or

EQUIPMENT

Figure B.1 – Eq ipme t plat orm

IEC

Annex C

(normativ )

Incidental y connected parts

In idental y con ected p rts are ac es ible con u tive p rts whic are neither rel a ly

con ected to, nor p sitively isolated from, e rth or an sp cified voltage

Examples of incidental y con ected p rts in lu e

– do rs an as embl es at ac ed by metal hin es,

– ad esively-b n ed la els whic have an ac es ible con u tive p rt ( or example, metal

foi ),

– p rts whic are atac ed to p inted or anodised s rfaces,

– control han les

Some prod ction samples of the EQUIPMENT may have an in identaly con ected p rt

ef ectively con ected to e rth or to another circ it In other samples, the same p rt may b

isolated from e rth an other circ its Sin e, in general, it is not cle r whic case wi prod ce

the hig er TOU H C RRENT, 6.2.2 req ires TOU H C RRENT to b me s red for b th cases in

order to fin the worst case However, where the predominant freq en y is b low 10 Hz, the

worst case is most l k ly to b that in whic the in idental y con ected p rt is con ected to

the other p rts

Annex D

(informativ )

Choice of cur ent l mits

When draf in the proced res sp cified in this stan ard, certain as umption were made

a out the c r ent l mits whic prod ct commit e s would u e This was neces ary in order to

select the a pro riate data from IEC T 60 7 -1 for desig of the me s rin networks in

Fig re 3, Fig re 4 an Fig re 5

These as umption were b sed on e rl er IEC publ cation Cur ent values given in this

an ex are examples only They are given b low for the as istan e of prod ct commit e s

when selectin c r ent l mits

D.2 Limit examples

D.2.1 Ve tric lar fibri lation

No lmit as umed

It is as umed that the l mits c osen for TOU H C RRENT wi b wel b low the thres old for

ventric lar fibri ation

D.2.2 Inabi ty to letgo-immobi ization

The method of me s rement is sp cified in this stan ard

IEC TS 6 4 9-1 as umes 10 mA r.m.s as the a proximate average thres old level of letg

o-immo i zation c r ent, where s 5 mA r.m.s as pro osed for IEC TS 6 4 9-1, would in lu e

the entire ad lt po ulation Se Fig re F.3 for the ef ects of freq en y

D.2.3 Startle-re ction

The method of me s rement is sp cified in this stan ard

The startle-re ction thres old given in IEC T 6 4 9-1 is a proximately 0,5 mA r.m.s for low

freq en ies Variou l mits are in u e b twe n the thres old for startle-re ction an letg

o-immo i zation

D.2.4 Perc ption thre hold

TOU H C R ENT can b p rceived at levels as low as a few micro mp res Unles the c r ent

is hig enou h to prod ce in olu tary startle-re ction that mig t res lt in harmful ef ects,

these smal tou h c r ents are not con idered hazardou an not u ual y me s red by these

method

D.2.5 Spe ial appl c tions

The method of me s rement sp cified in this stan ard can b u ed, u les otherwise

sp cified in the a pl ca le stan ard for the p rtic lar prod ct

0,2 mA r.m.s (one half of the startle-re ction thres old) is u ed for Clas I EQUIPMENT in

prod ct stan ard s c as IEC 6 0 5, IEC 6 3 5-1, IEC 6 9 0-1 an IEC 6 3 8-1 Se

Fig re F.2 for freq en y efects

Limits lower than 0,2 mA r.m.s are sp cified for some medical a pl cation For s c

a pl cation the method of me s rement in this stan ard may not provide an a pro riate

b d imp dan e model (se Clau e E.1)

D.3 Choice of l mits

Con ideration s ould b given to the ne d to sp cify dif erent l mits for (1) normal o eratin

con ition an (2) fault con ition

Se IEC TS 6 4 9 series for g idan e on the ef ects of c r ent p s in throu h the h man

b d

Limits are normal y expres ed in terms of maximum values of d.c an a.c at freq en ies up

to 10 Hz The method of me s rement sp cified in this stan ard are the same for letg

o-immo i zation, startle-re ction an some sp cial a pl cation Me s rin networks ta e into

ac ou t the ef ect of hig er- req en y c r ent on the b d an simulate lowerin of b d

imp dan e as frequen y in re ses L tgo-immo i zation, startle-re ction an p rce tion are

determined by p a values of c r ent, weig ted for freq en y For ELECTRIC BU N, r.m.s

values are sig ificant For the s o e of this stan ard, the efects of freq en y on ELECTRIC

BU NS are neglgible, sin e the predominant efect at low freq en y is startle-re ction or

letgo-immo i zation

Limits b sed up n ventric lar fibri ation (se D.2.1) are not neces ary for most EQUIPMENT,

sin e the lower TOU H CU RENT l mits for startle-re ction or letgo-immo i zation almost

alway prevent ventric lar fibri ation An ex e tion (dis u sed in IEC T 6 4 9-1) is where a

s ort d ration c r ent impulse can flow throu h the b d ( o s ort an impulse to cau e

ina i ty to let go), an startle-re ction from the c r ent impulse is not con idered hazardou

Ina i ty to let go has traditional y foc sed on GRIP ABLE PA T but this is now u dersto d to

b a simpl stic view Un er this con ition the hig est l mit value for contin ou c r ent is the

same as letgo-immo i zation (se D.2.2), ex e t for con ideration of ELECTRIC BU N

However, ELECTRIC BUR only b comes the predominant factor at hig freq en ies In the

ran e of the l mits for startle-re ction an letgo-immo i zation, there may b a secon ary

safety hazard d e to s rprise or in olu tary mu cle re ction, but no direct injury is exp cted

d e to c r ent throu h the b d Su h a c r ent may b con idered ac e ta le u der sin le

fault con ition , if so prod ct commit e s s ould sp cifical y provide an exemption

For s ort d ration c r ent, a lmit value hig er than that for letgo-immo i zation is sometimes

u ed, provided that it is s f iciently b low the ventric lar fibri ation an ELECTRIC BU N

thres old The network of Fig re F.3 mig t b sp cified by prod ct commit e s for s c a.c

me s rements where smal are contact is exp cted

The startle-re ction network of Fig re 4 s ould b u ed for me s rements where the startl

e-re ction l mit is u ed for smal are contact

It is u dersto d that the l mit values for low- req en y TOU H C R ENT in other IEC

publ cation are b sed up n the fol owin con ideration

– Limits for startle-re ction an lower l mits:

• ne d to avoid in olu tary startle-re ction, where severe con eq en es may res lt ( or

example, fal n from a lad er or dro pin EQUIPMENT);

• the l mit for startle-re ction is generaly 0,5 mA r.m.s or 0,7 mA p a for a sin soidal

c r ent;

• a l mit lower than 0,2 mA r.m.s (0,3 mA p a ) is in icated where the u er is

p rtic larly sen itive or at risk d e to en ironmental or biological re son

– L tgo-immo i zation:

• startle an some re ction are ac e ta le as an in ication of a first fault, when the

letgo-immo i zation l mit is a pl ed;

• men an women are estimated to have an average letgo-immo i zation thres old of

16 mA r.m.s an 10,5 mA r.m.s respectively;

• some p o le have a lower thres old, for example the 9 ,5 p rcenti es of men an

women have b en re orted as 9 mA r.m.s an 6 mA r.m.s resp ctively, an the

thres old values for c i dren are exp cted to b lower;

• certain sin le fault con ition may ju tify letgo-immo i zation l mits, with startl

e-re ction l mits a plyin for normal (non- ault condition

Certain EQUIPMENT typ s may have hig initial TOUC C R ENT when first switc ed on, whic

diminis es ra idly as EQUIPMENT is o erated This is normal y ig ored in setin EQUIPMENT

l mits when sp cified by the prod ct commit e

D.4 Electric burn ef e ts of touch cur ent

There is no general y ac e ted l mit value of TOUC C RRENT whic wi prevent ELECTRIC

BU NS in al cases Other p rameters, s c as the are of contact with the h man b d an

the d ration of contact, are known to b relevant The relation hip b twe n these p rameters

ne d further stu y When safe l mits are esta l s ed, they may b in terms of two or more of

these p rameters

The method of me s rement of TOUC C R ENT for con ideration of ELECTRIC BU N ef ects is

(Beck r, Malhotra an Hedley-Wh te)

Analy is of con ition le din to ELECTRIC BUR has s own that there is a cros over

freq en y where ELECTRIC BU N ex e d letgo-immo i zation an prod ct req irements

s ould reflect the ne d for ma in the cor ect me s rement to provide the pro er protection

IEC 6 3 8-1 reflects one a pro c to definin s c a req irement

Annex E

(informativ )

Networks for use in measurement of touch cur ent

Cur ent values given in this an ex are only examples

The networks of Fig re 3, Fig re 4 an Fig re 5 are inten ed for TOUC C RRENT

me s rements u in l mits in general u e by prod ct commit e s: for example, from 10 µA

r.m.s./14 µA p a up to a proximately 10 mA r.m.s./14 mA p a for a.c an d.c c r ents,

an coverin a freq en y ran e to 1 MHz for sin soidal, mixed freq en y an non-sin soidal

waveforms

E.2 Body impedance network – Figure 3

The purp se of the network of Fig re 3 is to

– simulate the imp dan e of the h man b d ,

– provide a me s rement in icatin the level of c r ent whic can flow throu h a h man

b d if the b d contacts the EQUIPMENT in a l k man er

NOT Th h ma b d mo el of Fig re 3 with th R a d C v lu s use h rein h s tra itio aly b e use in

pro u t safety sta d rds for 5 y ars or more; it h s a lo g history of a e u c for this me sureme t

TOU H C RRENT with regard to ELECTRIC BU N is eq al to U

1

r.m.s divided by 5 0 Ω

E.3 Startle-reaction (and body impedance) network – Figure 4

Startle-re ction by the h man b d is the res lt of c r ent flowin in the internal p rtion of

the b d

Con ideration of, an compen ation for, the freq en y variation of startle-re ction are

req ired for ac urate me s rement of this efect The network of Fig re 4 simulates b d

imp dan e an provides weig tin to fol ow the freq en y c aracteristic of the b d for

c r ent cau in in olu tary startle-re ction It has b en as umed that the s a e of the

freq en y c aracteristic is the same for re ction an startle, an the data esta l s in the

freq en y c aracteristic was actualy o tained throu h tests on the thres old of startle

The me s rement network is u a le for c r ent lmits up to the weig ted eq ivalent of a out

2 mA r.m.s at 5 Hz an 6 Hz The u e of this network for me s rement of hig er level

l mits is restricted by the con ideration of letgo-immo i zation an the ne d for diferent

freq en y weig tin where the ina i ty to let go is of con ern a ove these levels (se

E.4 Letgo-immobi ization (and body impedance) network – Figure 5

Immo i zation or the ina i ty to let go of an o ject is cau ed by c r ent flow internal to the

b d ( or example, throu h mu cles) The me s rement network is s ita le for c r ent l mits

a ove the weig ted eq ivalent of a out 2 mA r.m.s at 5 Hz and 6 Hz

The ef ect of freq en y on letgo-immo i zation l mits is diferent from its efect on startl

e-re ction, or on ELECTRIC BU N This is esp cial y true for freq en ies a ove 1 kHz where the

fi ter desig ta es this into ac ou t

The network of Fig re 5 simulates b d imp dan e an is weig ted to fol ow the freq en y

resp n e of the b d to c r ents whic can cau e tetanization of mu cles (in olu tary

mu c lar contraction) an , there y, an ina i ty to let go TOU H C R ENT with regard to the

letgo-immo i zation is eq al to U

3

p a divided by 5 0 Ω

Annex F

(informativ )

Measuring network l mitations and construction

The networks of Fig re 3, Fig re 4 an Fig re 5 are inten ed to prod ce a me s ra le

voltage resp n e whic a proximates the c rves given in Fig re F.1, Fig re F.2 an Fig re

F.3 The networks an referen e c rves provided are in general agre ment with those

publ s ed in IEC TS 6 4 9-1 an IEC TS 6 4 9-2, ex e t that, for simpl city of me s rement

circ its, sl g t deviation are alowed at the c rve inflection b twe n 3 0 Hz an 10 kHz

Where l mits for ELECTRIC BUR are sp cified, TOUC CU RENT is also me s red without

freq en y weig tin The criteria esta l s ed for ELECTRIC BUR wi over ide criteria for

startle-re ction or letgo-immo i zation if the r.m.s c r ent l mit for

ELECTRIC BUR is

ex e ded b fore the weig ted p a c r ent lmits for startle-re ction an letgo-immo i zation

are re c ed If this oc urs, it wi u ualy b in the ran e of 3 kHz to 5 0 kHz, de en in

up n the waveform of the c r ent an l mit values u ed Unles s c freq en ies are

predominant, no me s rement for ELECTRIC BU N l mit is neces ary

Figure F.1 – Fre ue c fa tor for ele tric burn

Figure F.2 – Fre ue c fa tor for perc ption or startle-re ction

IEC IEC

Figure F.3 – Fre ue c fa tor for letgo-immobi ization

IEC

Annex G

(informativ )

Construction and appl cation of touch cur ent measuring instruments

G.1 Considerations for selection of components

G.1.1 Ge eral

The selection of comp nents for the TOU H C R ENT me s rin networks in Fig re F.3,

Fig re 4 an Fig re 5 can b gre tly af ected by the a pl cation, for example, by the c r ent

levels an freq en ies that are to b me s red, an by the toleran es an p wer han l n

ca a i ty to b con idered

The me s rin networks an in truments an the p rforman e sp cification dis u sed in

this stan ard are a pro riate for b th sin soidal TOU H C R ENT waveforms from simple

EQUIPMENT an for non-sin soidal TOU H C R ENT waveforms from so histicated prod cts

that can generate hig freq en ies However, for a l mited a pl cation, it may not b

neces ary for a network to cover the complete ran e of d.c to 1 MHz, nor to with tan power

input levels that are u l k ly in the p rtic lar a pl cation Simpler c r ent me s rin networks

an in truments can b s bstituted for the sp cified networks an in truments, provided that

circ it con ition are s c that the re din s would b the same

Information provided here is inten ed to p int out the factors to b con idered for e c

comp nent, so that a pro riate decision can b made for p rtic lar a pl cation

G.1.2 Power rating a d inducta c for R

is determined by two factors One is the p s ibi ty of overlo d at d.c or

low freq en ies If, for example, a 2 0 V 50 Hz/6 Hz overlo d ca a i ty is desired, R

S

s al

tolerate 21,6 W an R

B7,2 W for at le st a s ort time, without s if in value However, if

overlo d are not a con ern, then 1/2 W or 1 W metal fi m resistors can provide adeq ate

ac urac , together with a low temp rature co f icient an lon - erm sta i ty

Based on the a ove c oices, the me s rin network s ould b a pro riately mark d, u les

it is ca a le of with tan in contin ou overlo d

R

B

may also dis ip te p wer from hig - req en y c r ents in some a pl cation For example,

if a c r ent at a burn hazard of 5 0 mA is to b me s red, a p wer of 12 W would b

dis ip ted in R

B

Althou h this is u l k ly, a resistor with this ca a i ty could b c osen

Wire wou d p wer resistors are avaia le to han le the p wer, if other factors s c as

ac urac an in u tive er ors are control ed to ac e table levels for the a pl cation Power

resistors with an ac urac of ± 1 % an ± 5 % are re di y avai a le In u tan e has b en

me s red on typical 12 W an 2 W wire wou d resistors an fou d to b a out 3 µH in a

1 0 0 Ω value Two s c resistors in p ral el give 5 0 Ω an the in u tan e would cau e a

2 % in re se in imp dan e to 510 Ω at 1 MHz The values of resistor R

B

network An in u tan e of 1 mH, whic

is mu h hig er than would b exp cted, in series with R

S(1 5 0 Ω), cau es les than 0,2 %

voltage ratin ca a le of with tan in s ort term overlo d, for example 2 0 V a.c or

p rha s 4 0 V d.c or 6 0 V d.c Fi m ca acitors rated for d.c wi u ual y tolerate an a.c

p a voltage eq al to the d.c ratin for s ort p riod without faiure If the in u tan e of C

S

an its wirin is to b control ed for p rforman e at 1 MHz, two or thre ca acitors in p ral el

may b neces ary to ac ieve ac urac an freq en y resp n e

0,1 µF fi m ca acitors rated 2 0 V a.c have b en me s red for resonan e at a out 3 MHz

Er ors of a proximately 3 % at 1 MHz can b exp cted d e to the in u tan e of s c

comp nents Ca acitors of lower value than 0,1 µF can b con ected in p ral el to red ce

the in u tive er or

G.1.4 Re istors R1, R2 a d R3

Metal fi m resistors wi give adeq ate p rforman e u der overlo d an at freq en ies up to

1 MHz If overlo d ca a i ty is desired (se G.1.2), R1 an R2 s ould b rated 1 W

G.1.5 Capa itors C1, C2 a d C3

Fi m typ ca acitors of exten ed foi con tru tion are recommen ed The in u tan e of

ca acitors in this ran e wi general y not res lt in sig ificant er ors up to 1 MHz Ca acitors

can b adju ted for toleran e by con ectin two or more smal er ca acitors in p ral el

G.2 Voltmeter

For ful p rforman e up to 1 MHz, the device u ed for me s rin U

1, U

– has an input ca acitan e not more than 2 0 pF for a.c me s rements;

– has a freq en y ran e for a.c me s rements from 15 Hz to 1 MHz, or more if hig er

freq en ies are in olved;

– has flo tin or diferential input with common mode rejection of at le st 4 dB up to

1 MHz

Se Clau e G.1 regardin the u e of simpler in truments for p rtic lar a pl cation

The overal ac urac of the TOU H C R ENT me s rin network an its voltmeter is influen ed

by the ac urac of resistors an ca acitors, an the freq en y resp n e, imp dan e an

ac urac of the voltmeter Intercomp nent ca acity an le d in u tan e also af ect the

ac urac of a me s rement

NOT An lysis of th efe ts of tolera c s o th me sure TOUCH CUR E T for th sp cifie R a d C

c mp n nts in th TOUCH CUR E T meter circ its sh ws th t tolera c of th resistors R

S

a d R

Bprimariy afe t

th me sureme t results Th efe ts of th oth r c mp n nt tolera c s are a ord r of ma nitu e lower

A voltmeter has b th an input resistan e an an input ca acitan e At d.c or low freq en ies,

a voltmeter havin an input resistan e of 1 MΩ u ed with the me s rin network of Fig re 4

or Fig re 5 wi in icate 1 % low d e to voltage division with the 10 0 0 Ω resistor in the

me s rin network At hig freq en ies, the input ca acitan e of the voltmeter, typical y

3 pF, b in directly in p ral el with the output ca acitor of the me s rin network, can

The p rforman e of an as embled TOU H C R ENT me s rin network or TOU H C RRENT

me s rin in trument can b determined by comp rin its re din s with calc lated ide l

values throu hout the freq en y ran e of interest (se Clau e K.1) The er or at e c

freq en y of me s rement s ould b noted for man sp cimen of e c in trument A

compi ation of er or data s ould b u ed to esta l s g ard b n s within whic future

me s rements are l k ly to oc ur Statistical confiden e in the statement regardin the width

of the g ard b n s can b sp cified If only one sp cimen of a p rtic lar desig of in trument

is bui t, the g ard b n can b the actual er or data

The esta l s ment of g ard b n s en ures that me s rements can re rod cibly in icate

whether the EQUIPMENT b in tested is within the TOUC C R ENT l mits, when u ed in the

fol owin way

For eq ipment man facturers, the g ard b n s ould b ad ed to the re din , an the s m

comp red to the l mit This en ures that EQUIPMENT in icated as complyin with the TOU H

CU RENT l mit wi not b rejected by the testin la oratory For testin la oratories, the g ard

b n s ould b alge raical y s btracted from the re din and the diferen e comp red to the

l mit This en ures that the testin la oratory wi not reject EQUIPMENT that actual y comples

with the l mit The toleran es for in truments u ed by a testin la oratory s ould b

s ficiently low to b ac ommodated by the dif eren e b twe n the l mit value an the

thres old of the u wanted ph siological efect (se IEC TS 6 4 9-1)

If neces ary, the g ard b n of a me s rin network can b made nar ower, for example by

– selection of comp nents,

– trimmin of comp nent values by con ectin one or more comp nents in p ral el,

– minimizin le d len th an s arp b n s in le d ( o red ce in u tan e),

– minimizin are s of p rts in proximity ( o red ce intercomp nent ca acitan es)

It is recommen ed that eq ipment man facturers minimize TOU H C R ENT levels The desig

of EQUIPMENT havin c r ent levels close to TOUC C R ENT l mit values is con idered to b

p or practice, d e to the efects of comp nent toleran e, agein , u e an en ironment on

TOU H CU RENT When the TOU H C R ENT from the EQUIPMENT is close to the l mit value,

special care s ould b ta en in me s rement precision an cal bration of the test EQUIPMENT

If the

TOU H C RREN

T is not close to the l mit value, a wider g ard b n wi b ac e ta le for

in truments u ed by a man facturer

G.5 Rec rds

For e c me s rin in trument, record s ould b esta l s ed containin p riodic

me s rements of the me s rin s stem These record wi provide data for s bseq ent

confirmation s stems (se Clau e G.6) an a out an l mitation in u e

G.6 Confirmation sy tems

NOT A d finitio of metrolo ic l c nfirmatio (sh rte e to “c nfirmatio ” in this sta d rd) is giv n in ma y

q alty sta d rds

Me s rin in truments u ed for EQUIPMENT certification s ould b s bjected to routine

confirmation of their ac urac (se Clau e K.2)