Iec 62135 1 2015

RESISTA NCE WELDING EQUIPMENT – Part 1: Safety requirements for design, manufacture and instal ation This p rt of IEC 6 13 a pl es to eq ipment for resistan e weldin an al ed proces es a

IEC 621 35- 1

Editio 2.0 2 15-0

Resist ance welding equipment –

Part 1: Safety requirement s for design, manufact ure and instal at ion

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IEC 621 35- 1

Edit io 2.0 2 15-0

R esist ance welding equipment –

Part 1: Safety requirement s for design, manufact ure and instal at ion

FOREWORD 6

1 Sco e 8

2 Normative ref eren es 8

3 Terms an def i ition 9

4 En ironmental con ition 1

5 Tests 1

5.1 Test con ition 1

5.2 Me s rin in truments 1

5.3 Typ tests 12 5.4 Routine tests 12 6 Protection again t electric s oc 1

2 6.1 General 12 6.2 In ulation 13 6.2.1 General 13 6.2.2 Cle ran es 1

3 6.2.3 Cre p ge distan es 14 6.2.4 In ulation resistan e 16 6.2.5 Dielectric stren th 16 6.2.6 Weldin circ it tou h c r ent 18 6.2.7 Liq id co l n 18 6.3 Protection again t electric s oc in normal service (direct contact 19 6.3.1 General 19 6.3.2 Rated no-lo d voltage at the output 19 6.3.3 Protection provided by b r iers or the en los re 2

6.3.4 Ca acitors 21

6.3.5 Automatic dis harge of input ca acitors 21

6.3.6 Protective con u tor c r ent u der normal con ition 2

6.3.7 Tou h c r ent in normal con ition 2

6.4 Protection again t electric s oc in case of a fault con ition (indirect contact 2

6.4.1 General 2

6.4.2 Protective provision for weldin circ it 2

6.4.3 Internal con u tors an con ection 3

6.4.4 Tou h c r ent in f ault con ition 3

6.4.5 DC resistan e weldin eq ipment o eratin at main feq en y 3

6.4.6 DC resistan e weldin eq ipment o eratin at medium feq en y 3

6.4.7 Contin ity of the protective b n in circ it 3

6.5 Ad itional u er req irements 3

6.6 Sup ly voltage 3

6.7 Con u tors of the weldin circ it 3

7 Thermal req irements 3

7.1 He tin test 3

7.1.1 Test con ition 3

7.1.2 Toleran es of the test p rameters 3

7.1.3 Begin in of the he tin test 4

7.2 Temp rature me s rement 4

7.2.1 Me s rements con ition 4

7.2.2 Sur ace temp rature sen or 4

7.2.3 Resistan e 4

7.2.4 Emb d ed temp rature sen or 41

7.2.5 Determination of the ambient temp rature ( a ) 41

7.2.6 Determination of co l n lq id temp rature ( a ) 41

7.2.7 Recordin of temp ratures 41

7.3 Limits of temp rature rise 4

7.3.1 Win in s 4

7.3.2 External s rf aces 4

7.3.3 Other comp nents 4

7.4 Protection f rom thermal hazard in normal service (direct contact 4

7.4.1 General 4

7.4.2 Identif i ation of hot s rf aces 4

7.4.3 Protection provided by in ulation or other b r iers 4

7.4.4 Protection provided by s p lemental co l n 4

8 Abnormal o eration 4

8.1 General req irements 4

8.2 Stal ed fan test 4

8.3 Co l n s stem f ai ure 4

8.4 Overlo d test 4

9 Provision again t mec anical hazard 4

9.1 General 4

9.2 Ris analy is 4

9.2.1 General 4

9.2.2 Re d -to-u e eq ipment as in del very state 4

9.2.3 Eq ipment not re d to u e as in delvery state 4

9.2.4 Eq ipment not re d for u e an desig ed to b in orp rated in more complex eq ipment 4

9.3 Me s res 4

9.3.1 Minimum me s res 4

9.3.2 Ad itional me s res 4

9.4 Conformity of comp nents 4

9.5 Startin for man al o erated eq ipment 4

10 In tru tion an markin s 4

10.1 In tru tion 4

10.2 Markin s 4

10.3 Markin of terminals 4

An ex A (informative) Nominal voltages of s p ly network 51

An ex B (normative) Con tru tion of s p ly circ it terminals 5

B.1 Size of terminals 5

B.2 Sp cin s b twe n s pply circ it terminals 5

B.3 Con ection at the terminals 5

B.4 Con tru tion of the terminals 5

B.5 Fixin of the terminals 5

An ex C (normative) Tou h c r ent me s rement in f ault con ition 5

An ex D (inf ormative) Extra olation of temp rature to time of s utdown 5

An ex E (informative) Example of ris analy is an safety level req irement 5

E.1 General 5

E.2 Monitored hazard 5

E.3 General me s res 5

E.4 Typical hazard by typ of eq ipment 5

E.4.1 General 5

E.4.2 Sp t weldin 5

E.4.3 Projection weldin 5

E.4.4 Se m weldin 6

E.4.5 But weldin 6

An ex F (informative) In irect contact protection in resistan e weldin eq ipment 61

F.1 Protection again t in irect contact by automatic dis on ection of the s p ly 61

F.1.1 General 61

F.1.2 TN s stem 61

F.1.3 T s stems 6

F.2 Automatic dis on ection of s p ly in sin le phase a.c c r ent eq ipment 6

F.2.1 TN s stem 6

F.2.2 T s stems 6

F.3 Automatic dis on ection of s p ly in d.c c r ent eq ipment o eratin at medium f req en y (in erter eq ipment 6

F.3.1 TN s stem 6

F.3.2 T s stems 6

Biblogra h 6

Fig re 1 – Me s rement of weldin circ it tou h c r ent 18 Fig re 2 – Me s rement of rms values 19 Fig re 3 – Example of metal s re n b twe n win in s of the s p ly circ it an the weldin circ it 2

Fig re 4 – Example of protective con u tor con ected directly to the weldin circ it (sin le-sp t, a.c c r ent eq ipment 2

Fig re 5 – Example of protective con u tor con ected directly to weldin circ its (multi-sp t, a.c c r ent eq ipment 2

Fig re 6 – Example of protective con u tor con ected directly to weldin circ its (medium-req en y eq ipment 2

Fig re 7 – Example of protective con u tor con ected to weldin circ its throu h imp dan es 2

Fig re 8 – Example of protective con u tor con ected to weldin circ its throu h auto-in u tan es 3

Fig re 9 – Example of protective con u tor con ected to weldin circ its throu h auto-in u tan es 3

Fig re 10 – Example of c r ent o erated RCD (a.c c r ent eq ipment 31

Fig re 1 – Example of c r ent o erated RCD (medium- req en y eq ipment 3

Fig re 12 – Example of c r ent o erated resid al c r ent device an voltage relay 3

Fig re 13 – Example of c r ent o erated resid al c r ent device an saf ety-voltage relay 3

Fig re 14 – Example of saf ety voltage relay 3

Fig re C.1 – Me s rin network f or weig ted tou h c r ent 5

Fig re C.2 – Diagram for tou h c r ent me s rement on fault con ition at o eratin

temp rature for sin le-phase con ection of a pl an es other than those of clas I 5

Fig re C.3 – Diagram for tou h c r ent me s rement on fault con ition for thre -phase four wire s stem con ection of a plan es other than those of clas I 5

Fig re E.1 – Stru ture of a mou ted mac ine 5

Fig re E.2 – Stru ture of a han -held weldin g n 5

Fig re E.3 – Stru ture of projection weldin mac inery 5

Fig re E.4 – Stru ture of se m weldin mac inery 6

Fig re E.5 – Stru ture of but weldin mac inery 6

Fig re F.1 – Prin iple i u tration of in ulation fault 61

Fig re F.2 – Il u tration of TN s stems 6

Fig re F.3 – Il u tration of TT s stems 6

Fig re F.4 – Typical fault c r ent 6

Fig re F.5 – Time-to-voltage referen e c rve 6

Ta le 1 – Minimum cle ran es for overvoltage category I 1

3 Ta le 2 – Minimum cre p ge distan es 15 Ta le 3 – In ulation resistan e 16 Ta le 4 – Dielectric test voltages 17 Ta le 5 – Minimum distan e throu h in ulation 2

Ta le 6 – Contin ity of the protective b n in circ it 3

Ta le 7 – Limits of temp rature rise f or win in s 4

Ta le 8 – Limits of temp rature rise for external s races of han -held eq ipment 4

Ta le 9 – Limits of temp rature rise f or external s rf aces of han -g ided eq ipment 4

Ta le 10 – Limits of temp rature rise for external s rf aces of f i ed eq ipment 4

Ta le B.1 – Ran e of con u tor dimen ion to b ac e ted by the s p ly circ it terminals 5

Ta le B.2 – Sp cin b twe n s p ly circ it terminals 5

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International Stan ard IEC 6 13 -1 has b en pre ared by IEC tec nical commit e 2 :

Electric weldin

This secon edition can els an re laces the f irst edition publs ed in 2 0 This edition

con titutes a tec nical revision

This edition in lu es the fol owin sig if i ant tec nical c an es with resp ct to the previou

edition:

– cre p ge distan es for p l ution degre 4 are no lon er val d (se Ta le 2);

– in ulation req irements f or Clas I eq ipment are defined (se Ta le 3);

– dielectric test voltage interp lation restriction lower lmit is c an ed to 2 0 V an

interp lation for control an weldin circ it is clarified (se Ta le 4);

– maximum temp rature for in ulation s stems are reviewed in ac ordan e with c r ent

– markin of terminals is defined (se 10.3);

– ta le for nominal voltages of s p ly network is c an ed ado tin Ta le B.2 of

IEC 6 6 4-1:2 0 in place of the Ta le B.1 values ref eren ed in the previou edition to

provide f or eq ipment to b con ected to b th e rthed an u e rthed s stems The

c an e imp cts the cre p ge an cle ran e distan e req irements for some s p ly

voltage ratin s (se An ex A);

– tou h c r ent in f ault con ition are me s rement proced res are clarified (se 6.4.4 an

An ex C)

– weldin circ it tou h c r ent is defined (se 6.2.6);

– tou h c r ent in normal con ition are clarified an moved in protection again t electric

s oc in normal service (se 6.3.7);

– he tin test con ition are clarified (se 7.1.1);

– external s r ace temp rature rise l mitation is c an ed (se 7.3.2)

The text of this stan ard is b sed on the folowin doc ments:

Ful inf ormation on the votin for the a proval of this stan ard can b foun in the re ort on

votin in icated in the a ove ta le

This publ cation has b en draf ted in ac ordan e with the ISO/IEC Directives, Part 2

The lst of al the p rts of the IEC 6 13 series, u der the general title Resista c wel d ing

e uipme t , can b f ou d on the IEC we site

The commit e has decided that the contents of this publ cation wi remain u c an ed u ti

the sta i ty date in icated on the IEC we site u der "htp:/we store.iec.c " in the data

related to the sp cific publ cation At this date, the publ cation wi b

• recon rmed,

• with rawn,

• re laced by a revised edition, or

A bi n ual version of this publcation may b is ued at a later date

IMPORTANT – The 'colour inside' logo on th cov r pa e of this publ c tion in ic te

that it contains colours whic are considere to be us f ul f or the cor e t

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colour printer

RESISTA NCE WELDING EQUIPMENT –

Part 1: Safety requirements for design,

manufacture and instal ation

This p rt of IEC 6 13 a pl es to eq ipment for resistan e weldin an al ed proces es an

in lu es sin le an multiple weldin station whic may b man al y or automatical y lo ded

an /or started

This p rt of IEC 6 13 covers stationary an p rta le eq ipment

This p rt of IEC 6 13 sp cifies electrical safety req irements f or desig , man f acture an

in tal ation It do s not cover al non-electrical safety req irements (e.g noise, vibration)

This p rt of IEC 6 13 do s not in lu e electromag etic comp tibi ty (EMC) req irements,

whic are in lu ed in IEC 6 13 -2

To comply with this stan ard, al safety ris s in olved in lo din , f eedin , o eratin an

u lo din the eq ipment, where a pl ca le, s ould b as es ed an the req irements of

related stan ard s ould b o served

The f ol owin doc ments, in whole or in p rt, are normatively ref eren ed in this doc ment an

are in isp n a le f or its a pl cation For dated ref eren es, only the edition cited a ples For

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

amen ments) a pl es

IEC 6 2 4-1:2 0 , Safet y of ma hinery – El ectric l e uipme t of ma hines – P art 1: Ge eral

re uireme ts

IEC 6 3 4-4-41:2 0 , L w-v l ta e el ectric l inst al l tio s – Part 4-41: P rotect ion for safety –

Prot ection a ainst electric sh c

IEC 6 3 4-6, L w-v ltag ele tric l nstal l at ions – Part 6: Verific tio

IEC 6 417-DB:2 1

1

, Gra hic l symb ls for use o e uipme t

IEC 6 4 5, Basic a d safety principles for ma -ma hine intera e, mark ing a d id entific tion

– Id entific tion of e uipme t t erminals, c nd uctor terminat ions a d c nduct ors

IEC 6 52 , De re s of protection pro id ed b e cl osures (IP Cod e)

IEC 6 66 -1:2 0 , Insul at ion c ord in tion for e uipme t wit hin l ow-voltag systems – P art 1:

P rinciples, re uireme ts a d tests

_ _ _ _ _ _

IEC 6 6 4-3, Insul ation c ord inat io for e uipme t within l ow-voltag systems – P art 3: Use

of c ating, p tting or mo ld ing for prote tio a ainst p l l t io

IEC 61 4 , P rotect ion a ainst electric sh c – Commo asp cts for install t ion a d

e uipme t

ISO 6 9, Resistan e wel ding – Resistan e wel d ing e uipme t – Mec a ic l a d electric l

re uireme ts

ISO 13 4 -1, Safety of ma hinery – Safety-rel ated p rts ofc nt rol systems – Part 1: Ge eral

prin iples for d esig

3 Terms and def initions

For the purp ses of this doc ment, the terms an def i ition given in ISO 6 9, IEC 6 6 4-1

an IEC 6 2 4-1, as wel as the f ol owin , a ply

3.1

e uipme t f or re ista c welding a d al ie proc s e

eq ipment as ociated with car yin out the proces es of resistan e weldin or al ed

proces es con istin of, f or example, p wer source, electrodes, to l n an as ociated

control eq ipment

Note 1 to e try: It ma b a s p rate u it or p rt of a c mple ma hin

Note 2 to e try: Th term " e ista c weldin e uipme t" is u e in th folowin te t

3.2

proc s e al ie to re ista ce weldin

proces es car ied out on mac ines comp ra le to resistan e weldin eq ipment con idered

as al ed to resistan e weldin , for example, resistan e brazin , solderin or he tin

3.3

type te t

test of one or more devices made to a given desig , to c ec if these devices comply with the

requirements of the stan ard con erned

[SOURCE: IEC 6 0 0-8 1:2 0 , 8 1-12-0 ]

3.4

routine te t

test made on e c in ivid al device d rin or af ter man facture to c ec if it compl es with

the req irements of the stan ard con erned or the criteria sp cif ied

3.7

con e tional v lue

stan ardized value that is u ed as a me s re of a p rameter f or the purp ses of comp rison,

cal bration, testin , etc

Note 1 to e try: Co v ntio al v lu s d n t n c s ariy a ply d rin th a tu l weldin pro e s

materials are se arated into four groups by their comp rative trac in in ex (CTI) values

Note 1 to e try: Th gro p are a folows:

Th CTI v lu s a o e ref er to v lu s in a c rd n e with IEC 6 1 2

Note 2 to e try: For in rg nic in ulatin materials, for e ample, gla s or c ramic , whic d n t tra k, cre p g

dista c s n e n t b gre ter th n th ir a s ciate cle ra c for th p rp s of in ulatio c ordin tio

s stem inten ed to en ure the protection of al or p rt of the weldin eq ipment again t

ex es ive temp ratures res ltin f rom certain con ition of thermal overlo d

Note 1 to e try: It is c p ble of b in re et (eith r ma u ly or a tomatic ly) wh n th temp rature f als to th

re et v lu

in p ction by eye to verify that there are no a parent dis re an ies with resp ct to provision

of the stan ard con erned

3.18

working volta e

hig est r.m.s value of the a.c or d.c voltage acros an p rtic lar in ulation whic can oc ur

when the eq ipment is s p l ed at rated voltage

Note 1 to e try: Tra sie ts aredisre ard d

Note 2 to e try: Both o e -circ it c n itio s a d n rmalo eratin c n itio s are ta e into a c u t

4 Environme tal conditions

Resistan e weldin eq ipment inten ed for in o r u e an complyin with this stan ard s al

b safe to o erate when the fol owin en ironmental con ition prevai :

a) ran e of ambient air temp rature:

d rin o eration: 5 °C to 4 °C;

b) relative h midity of the air:

up to 5 % at 4 °C;

up to 9 % at 2 °C

c) ambient air, fe f om a normal amou ts of d st, acid , cor osive gases or s bstan es

etc other than those generated by the weldin proces

d) altitu e a ove se -level up to 1 0 0 m;

e) temp rature of the co ln medium do s not ex e d:

1) in the case of a l q id: 3 °C at the inlet;

2) in the case of the ambient air: 4 °C

NOT Diff ere t e viro me tal c n itio s c n b a re d u o b twe n th ma ufa turer a d th p rc a er a d

th re ultin weldin e uipme t is mark d a c rdin ly Ex mple of th s c n itio s are: o td or u e, dif fere t

altitu e, dif fere t temp rature of c oln me ium, hig h midity, u u u ly c ro iv f ume , ste m, e c s iv oi

v p ur, a n rmal vibratio or s o k, e c s iv d st, u u u l s a c a t or s ip o rd c n itio s

5.1 Te t condition

The tests s al b car ied out on new, dry an completely as embled resistan e weldin

eq ipment at an ambient air temp rature b twe n 10 °C an 4 °C It is recommen ed that

the thermal tests b car ied out at 4 °C Liq id-co led resistan e weldin eq ipment s al b

tested with l q id con ition as sp cif ied by the man f acturer

5.2 Me s rin instrume ts

The ac urac of me s rin in truments s al b as folows

a) electrical me s rin in truments: clas 1 (±1 % of ful-s ale re din ), ex e t for the

me s rement of in ulation resistan e an dielectric stren th where the ac urac of the

in truments is not sp cified, but s al b taken into ac ou t f or the me s rement;

b) in truments f or me s rin weldin c r ent: clas 5;

c) temp rature me s rin in truments: ± K

5.3 Type te ts

Unles otherwise sp cif ied, the tests in this stan ard are typ tests

The resistan e weldin eq ipment s al b tested with al an i ary eq ipment fit ed that could

aff ect the test res lts

Al typ tests s al b car ied out on the same resistan e weldin eq ipment ex e t where it

is sp cified that a test may b car ied out on another resistan e weldin eq ipment

As a con ition of conformity, the typ tests given b low s al b car ied out in the fol owin

a) general vis al in p ction, se 3.17;

b) in ulation resistan e, se 6.2.4 (prel minary c ec );

c) protection provided by the en los re, se 6.3.3;

d) in ulation resistan e, se 6.2.4;

The req irements f or provision for normal con ition protection are given in 6.3

The req irements f or provision f or fault con ition protection are given in 6.4

6.2 In ulation

The majority of resistan e weldin eq ipment f al s within overvoltage category I in

ac ordan e with IEC 6 6 4-1 Al resistan e weldin eq ipments s al b desig ed for u e in

en ironmental con ition of p l ution degre 3 as a minimum

Desig of l q id co led eq ipment s al con ider p s ible con en ation whic may req ire

diff erent con ition

Comp nents or s b s embl es with cle ran es or cre p ge distan es cor esp n in to

p l ution degre 2 are p rmit ed, if they are completely co ted, p ted or moulded in

ac ordan e with IEC 6 6 4-3

An eq ipment desig ed with in ulation b sed on l ne-to-neutral voltage values s al b

provided with a caution that s c eq ipment s al only b u ed on a s p ly s stem that is

either a thre -phase, f our wire s stem with an e rthed neutral or a sin le-phase, thre -wire,

s stem with an e rthed neutral

For b sic in ulation or s p lementary an reinf orced in ulation, minimum cle ran es s al b

in ac ordan e with IEC 6 6 4-1, as p rtial y s mmarized in Ta le 1 f or overvoltage

category I I

Table 1 – Minimum cle ra c s for ov rvolta e c te ory I

Ba ic or su plementary insulatio Reinf orc d insulatio

Voltage

aRated

For dimen ionin cle ran es to ac es ible non-con u tive s rf aces, s c s r aces s al b

con idered to b covered by metal f oi wherever they can b tou hed by the stan ard test

f i ger in ac ordan e with IEC 6 5 9

Cle ran es s al not b interp lated

For s p ly circ it terminals, se An ex B

Cle ran es b twe n p rts of resistan e weldin eq ipment (for example, circ its or

comp nents) whic are protected by an overvoltage lmitin device (f or example, oxide

varistor) may b rated in ac ordan e with overvoltage category I (se IEC 6 6 4-1)

The values of Ta le 1 s al also a ply to control circ its when se arated f om the s p ly

circ it, f or example, by a tran f ormer

If the control circ it is con ected direct to the s p ly circ it, the values for the s p ly voltage

s al a ply

Co formity sh l l b c e k d b me sureme t in a c rd an e wit h 6.2 ofIEC 6 6 4-1:20 7 or

wh re t his is n t p s ible, b su mitting t he wel d in e uipme t t o a imp lse t est using th

v ltag s given in Ta l e 1

For the impulse test, a minimum of thre impulses of e c p larity at the voltage given in

Ta le 1 are a pl ed with an interval of at le st 1 s b twe n impulses u in a generator with an

output wavef orm of 1,2/5 µs an an output imp dan e of les than 5 0 Ω

Alternatively, either an a.c test voltage as given in Ta le 1 may b a pl ed f or thre c cles or

a rip le f re d.c voltage, the value of whic is eq al to the impulse voltage, may b a pl ed

thre times for 10 ms, f or e c p larity

The eq ipment s al with tan the test voltages without an flas over or bre k own

6.2.3 Cre pa e dista c s

For b sic in ulation or s p lementary in ulation, minimum cre p ge distan es s al b in

ac ordan e with IEC 6 6 4-1, as s mmarized in Ta le 2

Cre p ge distan es for reinforced or double in ulation s al b twice those determined for

b sic in ulation

For the purp se of dimen ionin cre p ge distan es to ac es ible s rf aces of in ulation

material, s c s races s al b con idered to be covered by metal foi wherever they can b

tou hed by the stan ard test fin er in ac ordan e with IEC 6 5 9

Cre p ge distan es are given for the hig est rated voltage of e c l ne of Ta le 2 In the case

of a lower rated voltage, interp lation is alowed

For s p ly circ it terminals, se An ex B

The values of Ta le 2 s al also b a plca le to control circ its when se arated fom the

s p ly circ it by, for example, a tran former

A cre p ge distan e can ot b les than the as ociated cle ran e, so the s ortest p s ible

cre p ge distan e is eq al to the req ired cle ran e

If the control circ it is con ected directly to the s p ly circ it, the values f or the s p ly

voltage s al a ply

I EC 6 6 4-1:2 07

Table 2 – Minimum cre pa e dista c s

Workin

v ltage

Cre page distanc s in mi imetre

Ba ic or su plementary insulatio

Printed wirin material

NOT In a c rd n e with IEC 6 6 4- , th dime sio s for cre p g dista c c n ot b s e ifie wh re

p rma e tly c n u tiv p lutio is pre e t (Polutio d gre 4)

6.2.4 In ulation re ista c

The in ulation resistan e s al b not les than the values given in Ta le 3

Table 3 – Ins lation re ista c

Me surement

a

Re istanc

S p ly circuit (in lu in c ntrol circ its c n e te

to it) with prote tio pro isio s e ifie in 6.4.2.2

to weldin circuit (in lu in c ntrol

circ its c n e te to it)

5,0 MΩ

S p ly circuit (in lu in c ntrol circ its c n e te

to it) with prote tio pro isio dif fere t fom th s

s e if i d in 6.4.2.2

to weldin circuit (in lu in c ntrol

circ its c n e te to it)

An control or au i ary circ it con ected to the protective con u tor terminal s al b

con idered as an exp sed con u tive p rt for the purp se of this test

Co formity sh ll b c e k d b th st abil ized me sureme t of th insulation resist an e

witho t int erere c su pres io or protection c p cit ors (se 6.4.2.2) b a p c t ion ofa d c

v ltag of 50 V at ro m temp rature

Durin the test, electric comp nents that may b damaged an are not p rt of the in ulation

to b tested can b dis on ected or s ort-circ ited Test re ort s al contain a l st of these

comp nents with a ju tification of ex lu ion by the test

Test is p rf ormed without co l n l q id

6.2.5 Diele tric stre gth

The in ulation s al with tan the fol owin test voltages without an flas over or bre k own:

a) f irst test of a resistan e weldin eq ipment: test voltages given in Ta le 4;

b) re etition of the test of the same resistan e weldin eq ipment: test voltage 8 % of the

values given in Ta le 4

Table 4 – Diele tric te t volta e

,

weldinb

parts, su ply circuit to al circuits

exc pt the weldin circuit

NOT 1 Th ma imum rate v lta e is v ld f or e rth d a d u e rth d s stems

NOT 2 In this sta d rd th diele tric stre gth te t of c ntrol circ its is lmite to a y circ it th t e ters or e its

th e clo ure a art f rom th s p ly circ it a dth weldin circ it

a

For interme iate v lu s, interp latio is alowe o al s p ly n twork (s p ly circ it) o eratin o tsid th

ra g of 2 0 V to 4 0 V a d o al thre -p a e, thre -wire e rth d s stems with ut v lta e e emptio (s e

An e A)

b

For interme iatev lu s, interp latio is alowe o weldin a d c ntrol circ its

The a.c test voltage s al b of an a proximate sine wave-f orm with a p ak value not

ex e din 1,4 times the r.m.s value, havin a f req en y of a proximately 5 Hz or 6 Hz

The hig -voltage tran former s al del ver the pres rib d voltage up to the trip in c r ent

Trip in is regarded as a f las over or a bre k own The trip in c r ent setin can b

selected ac ordin to the tran former ca acitive disp rsion c r ent The maximum p rmis ible

set in of the trip in c r ent s al b 10 mA

For o erator’s safety, the lowest setin of the trip in c r ent (les than or eq al to 10 mA) is

recommen ed

Alternativ te t: A d.c test voltage of 1,4 times the r.m.s test voltage may b u ed

Comp nents or s b s embl es s al not b dis on ected or s ort-circ ited u les the

con ition of a), b) or c) b low are met

a) The comp nents or s b s embles are desig ed an tested to relevant stan ard that

sp cify a voltage lower than the test voltage level of this stan ard These comp nents or

s b s embl es are not con ected b twe n s p ly an weldin circ its an their

dis on ection or s ort-circ itin do s not prevent a p rt of that circ it f om b in tested

Example: fan motors an pump motors

b) The comp nents or s b s embl es are completely in orp rated within either the s p ly or

the weldin circ it an their dis on ection do s not prevent a p rt of that circ it fom

b in tested Example: electronic circ its

c) Inter eren e s p res ion network or protection ca acitors b twe n the s p ly or weldin

circ it an an exp sed con u tive p rt conf orm to the relevant stan ard

Control circ its con ected to the protective con u tor terminal s al not b dis on ected

d rin testin an they are then tested as exp sed con u tive p rts

The test voltage may b raised to the ful value slowly at the dis retion of the man f acturer

Resistan e weldin eq ipment in orp ratin a rectifier s al b tested af ter as embly of the

complete resistan e weldin eq ipment, with the p wer rectif ier remainin pro erly con ected

to the output circ it of the tran former Rectifiers, their protective devices an other sol d

-state electronic comp nents or ca acitors, may b s ort-circ ited d rin the test

Liq id-co led eq ipments s al b tested b f ore b in fi ed with the co l n l q id

Co formity sh l l b c e k d b a p c tio of th test volt ag for

1) 6 s (type test );

2) 5 s (o tin test); or

3) 1 s (o tin test wit h t he test voltag in re sed b 2 %)

6.2.6 Welding circ it touc c r e t

In eq ipment with weldin circ it in ulated fom the protective con u tor the tou h c r ent

b twe n the weldin circ it con ection an the protective con u tor terminal s al not

ex e d 14,1 mA p ak

Co formity sh ll b c e k d b visu l insp ct io a d me sureme t of the tou h c re t with a

circ it as sh wn in Fig re 1 at t he rated su ply v lt ag (s) a d n -load c nd ition

The me s rin network sp cified in Fig re C.1 s al b con ected as s own in Fig re 1

Key

A, B Me s rin n twork c n e tio s

NOT For cla s I e uipme t, u e th PE-termin l of e rth d s p ly n twork

Figure 1 – Me s reme t of welding circ it tou h c r e t

6.2.7 Liq id cool ng

Co lant-hoses b twe n p rts of the input circ it havin diff erent p larity s al have a len th of

at le st 0,5 m an a resistan e of at le st 1 MΩ/m; resistivity of the co l n l q id s al b at

le st 2 Ωm

Ac es ible con ection of a co l n -s stem b in in contact with the input circ it s al b

provided with a metal p rt to b con ected to the protective con u tor

Compl ian e is c e k d b visu l insp ct ion a d me sureme t

IEC

6.3 Prote tion a ainst ele tric s oc in normal s rvic (dire t conta t)

Protection again t electric s oc in normal service s al con ist of one or more provision that

u der normal con ition prevent contact with hazardou -l ve-p rts These provision in lu e

– b sic in ulation;

– b r iers or en los res;

– lmitation of voltage;

– lmitation of ste d -state tou h c r ent an c arge

More detai s may b f ou d in IEC 61 4

6.3.2 Rate no-loa volta e at the output

If the weldin circ it is ac es ible d rin weldin proces an the weldin p wer source is not

f ited with a hazard red cin device in ac ordan e with 6.3.2.3, the rated no-lo d voltage at

the output, at al p s ible setin s, s al not ex e d 2 V a.c r.m.s or 6 V rip le- re d.c

If the weldin circ it is ac es ible d rin weldin proces an the weldin p wer source is

f ited with a hazard red cin device in ac ordan e with 6.3.2.3, the rated no-lo d voltage at

the output, at al p s ible setin s, s al not ex e d a.c 6 V p ak an 4 V r.m.s

Co formity sh ll b c e k d b me sureme t a d b a alysis of the circ it a d/or b fail ure

6.3.2.2 Me s rin circ its

For me s rin r.m.s values, a true r.m.s meter s al b u ed together with a resistor of

5 ± 5 % kΩ, con ected acros the weldin circ it terminals as s own in Fig re 2

0

6.3.2.3 Hazard re ucing de ic

6.3.2.3.1 Ge eral re uireme ts

A hazard red cin device s al red ce the severity of the electric s oc that can originate

f rom no-lo d voltages ex e din a.c 2 V

6.3.2.3.2 Volta e re ucing de ic

A voltage red cin device s al have automatical y red ced the rated no-lo d voltage to a

level not ex e din a.c 2 V The o eratin time is 0,1 s

Co formity sh ll b c e k d b me surin v ltag a d o eratin time

6.3.2.3.3 In ic tion of satisfa tory operation

A rel a le device, f or example a sig al lamp, s al b provided whic in icates that the hazard

red cin device is o eratin satisfactori y Where a sig al lamp is u ed, it s al l g t when the

voltage has b en red ced

Co formity sh ll b c e k d b visu l insp ct io

6.3.2.3.4 Fai to a s fe condition

If the hazard red cin device f ai s to o erate in ac ordan e with 6.3.2.3.1, the voltage at the

output terminals s al b red ced to a level not ex e din a.c 2 V an s al not b reset

automatical y

Conf ormity s al b c ec ed by simulatin a f ault of the hazard red cin device an

me s rin the time to re c a safe con ition af ter f ai ure of the hazard red cin device

6.3.3 Prote tion provid d by bar iers or the e clos re

Bar iers or en los res s al prevent ac es to hazardou -l ve-p rts by providin an adeq ate

degre of protection again t electric s oc Bar iers or en los res s al have s ff i ient

mec anical stren th, sta i ty an d ra i ty to maintain the sp cified degre of protection,

takin ac ou t of al relevant influen es fom the en ironment an fom in ide the en los re

Resistan e weldin eq ipment sp cifical y desig ed for in o r u e s al have a minimum

degre of protection of IP2 (ex e t external weldin circ it, for example, electrodes) u in

IEC 6 5 9 test proced res an con ition

Resistan e weldin eq ipment sp cif i al y desig ed f or outdo r u e s al have a minimum

degre of protection of IP2 u in IEC 6 5 9 test proced res an con ition

Co formity sh l l b c e k d as fol l ows

Weldin eq ipment s al b s bjected to the a pro riate water test without b in energized

Immediately af ter the test, the u it s al b moved to a safe en ironment an s bjected to the

in ulation resistan e an dielectric stren th tests

Where the desig or con tru tion alows f or the removal of b r iers, the o enin of en los res

or the removal of p rts of en los res, ac es to hazardou -l ve-p rts s al only b p s ible

– by the u e of a key or to l;

– after isolation of hazardou -l ve-p rts f rom the s p ly circ it where the en los re would no

lon er provide protection, restoration of the s p ly s al b come p s ible only af ter

re lacement of b r iers or p rts of en los res or after the closin of do rs;

– where an intermediate b r ier sti maintain the req ired degre of protection, s c

c) b contained within the resistan e weldin eq ipment en los re or other en los re whic

conforms to the relevant req irements of this stan ard

Co formity sh l l b c e k d b visu l insp ct ion

Ca acitors s al not cau e the resistan e weldin eq ipment to ex ibit hazardou electrical

break own or present ris of fire in event of a f ai ure

Co formity sh l l b c e k d b the fol l owing test

Ca acitors are s orted b fore the eq ipment is switc ed on then the resistan e weldin

eq ipment is o erated at no-lo d at its rated input voltage an with an input s p ly fu e or

circ it-bre ker with a value b twe n 12 % an 2 0 % of those sp cified in the in tru tion

man al, with al or an of the ca acitors s orted u ti

a) an fu e or overc r ent device in the resistan e weldin eq ipment source has o erated;

or

b) the s p ly circ it fu e or circ it-bre ker has cle red; or

c) the input comp nents of the resistan e weldin eq ipment re c a ste d -state

temp rature, not hig er than that al owed in 7.3 Any fault of electronic comp nents (f or

example, primary rectif ier) is not me nt as a fai ure criteria for this test

If an u d e he tin or meltin b comes a p rent, the resistan e weldin eq ipment s al

conform to the req irements of b) an c) of 8.1

There s al b no le kage of l q id d rin an of the typ tests req ired by this stan ard

For interf eren e s p res ion ca acitors or ca acitors havin internal fu ing or a circ it

breaker, this test is not req ired

6.3.5 Automatic dis harge of input c pa itors

Eac ca acitor s al b provided with a me n of automatic dis harge whic s al red ce the

voltage acros the ca acitor to 6 V or les within the time neces ary to give ac es to an

c r ent-car yin p rt con ected to the ca acitor or an a pro riate warnin la el s al b u ed

For an plu , whic has a voltage d e to a ca acitor, the ac es time is con idered to b 1 s

Ca acitors havin a rated ca acitan e not ex e din 0,1 µ are not con idered to present a

ris of electric s oc

Co formity sh l l b c e k d b visu l insp ct ion a d b the fol l owing t es

The resistan e weldin eq ipment s al be tested at its hig est rated s p ly voltage The

resistan e weldin eq ipment s al then b dis on ected fom the s p ly an the voltages

are me s red with in truments that do not sig ificantly af fect the values b in me s red

6.3.6 Prote tiv cond ctor c r e t under normal condition

The le kage c r ent in the external protective con u tor s al not ex e d

a) 5 mA rms for plu -con ected eq ipment rated up to an in lu in 3 A;

b) 10 mA rms f or plu -con ected eq ipment rated more than 3 A;

c) 10 mA rms for eq ipment f or p rmanent con ection, without sp cial me s res for the

protective con u tor;

d) eq ipment f or p rmanent connection with a reinforced protective con u tor may have a

le kage c r ent up to 5 % of the rated input c r ent p r phase

The f ol owin s al b provided for reinf orced protective con u tors:

– a con ection terminal desig ed f or the con ection of a protective con u tor me s rin at

– a secon terminal desig ed f or the con ection of a protective con u tor of the same

cros -section as that of the normal protective con u tor

Co formity sh l l b c e k d u d er the foll owing c nd itions

The external protective con u tor c r ent s al b me s red by in ertin an ammeter of

negl gible imp dan e (for example, 0,5 Ω) in series with the protective con u tor

Me s rement of the protective con u tor is made with the eq ipment an p wer distribution

s stem ru nin in al normal o eratin modes

6.3.7 Tou h c r e t in normal con ition

The tou h c r ent f or ac es ible con u tive s r aces, not con ected to the protective circ it,

s al not ex e d 0,7 mA p ak u der normal con ition

Conf ormity s al b c ec ed u in the config ration as s own in An ex C, without simulatin

an fault an u der the fol owin con ition :

a) the resistan e weldin eq ipment is:

– isolated f rom the grou d plane;

– s p l ed by the highest rated s p ly voltage;

b) the weldin circ it is in the no-lo d con ition;

c) interf eren e s p res ion ca acitors are not dis on ected

6.4 Prote tion a ainst ele tric s oc in c s of a fa lt condition (indire t conta t)

6.4.1.1 Ge eral s f ety me s re

Protection again t in irect contact is inten ed to prevent hazardou situation d e to an

in ulation f ault b twe n l ve p rts an exp sed con u tive p rts

For e c circ it or p rt of electrical eq ipment at le st one me s re s al b a pl ed Suita le

me s res for the weldin circ it are given in 6.4.2.2 an a plca i ty to dif ferent typ of

eq ipment is given in 6.4.2.2 to 6.4.2.4

For e c circ it or p rt of the electrical eq ipment dif ferent f rom the weldin circ it, at le st

one of the me s res in ac ordan e with 6.4.1.2 to 6.4.1.3 s al b a pl ed:

– me s res to prevent the oc ur en e of a tou h voltage (6.4.1.2); or

– automatic dis on ection of the s p ly b f ore the time of contact with a tou h voltage can

Where those recommen ed me s res are not practica le, for example, d e to the phy ical or

o erational con ition , other me s res fom IEC 6 3 4-4-41 may b u ed

If selected me s re(s) neces itate(s) co rdination with the typ of s p ly an e rthin

s stem, the man facturer can req ire p wer s p ly e rthin s stem inf ormation f om the u er

an desig the eq ipment in ac ordan e with that inf ormation (for example, u in the en uiry

f orm sp cified in An ex B of IEC 6 2 4-1:2 0 )

The man facturer s al sp cify in the in tru tion man al the s p ly e rthin s stem(s)

al owed (for example, TN/TT/IT s stems) an the relevant req ired s p ly c aracteristic (f or

example, fu e, circ it-bre ker, an /or RCD ratin )

NOT 1 Th ris of h rmf ul p y iolo ic l ef fe ts f rom a to c v lta e d p n s o th v lu of th to c v lta e

a d th d ratio of p s ible e p s re

NOT 2 For cla s s of e uipme t a d prote tiv pro isio s, s e IEC 61 4

6.4.1.2 Pre e tion of the oc ur e c of a touc volta e

Me s res to prevent the oc ur en e of a tou h voltage in lu e the fol owin :

– provision of clas I eq ipment or by eq ivalent in ulation;

– electrical se aration

Protection by provision of clas I eq ipment or by eq ivalent in ulation is inten ed to prevent

the oc ur en e of tou h voltages on the ac es ible p rts throu h a f ault in the b sic

in ulation This protection is provided by one or more of the fol owin :

– clas I electrical devices or a p ratu (double in ulation, reinf orced in ulation or by

equivalent in ulation in ac ordan e with IEC 61 4 );

– switc ge r an controlge r as embl es havin total in ulation;

– s p lementary or reinf orced in ulation in ac ordan e with 413.2 of IEC 6 3 4-4-41:2 0

Protection by electrical se aration is inten ed to prevent a tou h voltage throu h contact with

exp sed con u tive p rts that can b energized by a fault in the b sic in ulation of the lve

p rts of that circ it F r this typ of protection, the req irements of IEC 6 3 4-4-41 a ply

6.4.1.3 Prote tion by a tomatic dis onne tion of s pply

This me s re con ists of the inter uption of one or more of the l ne con u tors by the

automatic o eration of a protective device in case of a fault This inter uption s al oc ur

within a s ff i iently s ort time to lmit the d ration of a tou h voltage to a time within whic the

tou h voltage is not hazardou Inter uption times are given in IEC 6 3 4-4-41

This me s re neces itates co-ordination b twe n

– the typ of s p ly an e rthin s stem;

– the imp dan e values of the dif ferent elements of the protective b n in s stem;

– the c aracteristic of the protective devices that detect in ulation fault s);

– the c aracteristic of fault c r ent (for example, wave s a e, f eq en y content

Automatic dis on ection of the s p ly of an circ it aff ected by an in ulation f ault is inten ed

to prevent a hazardou situation res ltin f rom a tou h voltage

This protective me s re comprises b th:

– protective b n in of exp sed con u tive p rts;

– an either:

a) overc r ent protective devices for the automatic dis on ection of the s p ly on

detection of an in ulation f ault in TN s stems; or

b) resid al c r ent protective devices to initiate the automatic dis on ection of the s p ly

on detection of an in ulation f ault fom a l ve p rt to exp sed con u tive p rts or to

e rth in TT s stems, or

c) in ulation monitorin or resid al c r ent protective devices to initiate automatic

dis on ection of IT s stems Ex e t where a protective device is provided to inter upt

the s p ly in the case of the f irst e rth fault, an in ulation monitorin device s al b

provided to in icate the oc ur en e of a f irst f ault f rom a l ve p rt to exp sed

con u tive p rts or to e rth This in ulation monitorin device s al initiate an au ible

an /or vis al sig al whic s al contin e as lon as the f ault persists

NOT In larg ma hin s, th pro isio of a e rth f ault lo atio s stem c n f aci tate mainte a c

Where automatic dis on ection is provided in ac ordan e with a), an dis on ection within

the time sp cif ied in IEC 6 3 4-4-41 can ot b as ured, s p lementary b n in s al b

provided to prevent a prosp ctive tou h voltage fom ex e din 5 V a.c or 12 V rip le-re

d.c b twe n simultane u ly ac es ible con u tive p rts

In the event of f ai ure, the protective device s al o erate to isolate the eq ipment fom the

p wer s p ly within the time sp cified in IEC 6 3 4-4-41 De en in on the selected

provision, the dis on ectin device can b in orp rated in the eq ipment by the man facturer

or provided at the in tal ation The selection of a pro riate dis on ectin device typ an its

c aracteristic is determined f rom b th eq ipment p rameters (fault c r ent c aracteristic ,

eq ipment ad itional f ault loo imp dan e) an in tal ation p rameters (f or example, e rthin

s stem typ , fault lo p imp dan e, e rth con ection resistan e, etc) If the dis on ectin

device is not in orp rated in the eq ipment but provided at in talation, the man facturer s al

sp cify to the u er a pro riate information to al ow pro er selection (f or example, req ired

RCD typ , maximum e rth con ection resistan e, information on the eq ipment ad itional

f ault lo p imp dan e, etc.)

6.4.2 Prote tiv provisions for welding circ it

To provide protection in the case of f ai ure b twe n input an the output circ its, in contact

with the workpieces, one of the provision des rib d in 6.4.2.2 to 6.4.2.1 s al b ado ted

Con ection of the protective con u tor to the tran former core or fame is req ired when

these p rts are ac es ible by the o erator

The provision des rib d in 6.4.2.4 to 6.4.2.10 are b sed on automatic dis on ection of the

s p ly (se 6.4.1.3)

If the weldin circ it is con ected direct to grou d (i.e 6.4.2.4 is a pled), exec tion of the

weldin proces on non-in ulated workpieces can generate a c r ent circ lation in the

protective con u tor Ampl tu e of this c r ent de en s on many factors, for example,

in lu in the typ of weldin c r ent (i.e a.c or d.c.), the value of the secon ary voltage, the

imp dan e or resistan e of the in talation protective con u tors p th where the c r ent

circ lates As this stray c r ent can en an er the integrity of the protective con u tor, the

man facturer s al inf orm the u er of the eq ipment u der whic provision the eq ipment is

s ita le for the weldin of non-in ulated workpieces without s f ferin f rom this dan er (f or

example, in tal ation an verification req irement

For in irect multi-sp t weldin with protective provision ac ordin to 6.4.2.3 to 6.4.2.9, the

work-piece an b c in electrodes s al b in ulated f om the protective con u tor if

ex es ive grou d c r ents lkely to en an er the integrity of the protective con u tor can ot

b avoided

6.4.2.2 Double or reinf orc d isolation of the weldin circ it

The weldin circ it s al b electrical y isolated f rom the s p ly circ it, an f rom al other

circ its havin a voltage hig er than the al owa le no-lo d voltage in ac ordan e with 6.3.2

(for example, au i ary p wer s p ly circ its), by double or reinforced in ulation in ac ordan e

with 6.3

Betwe n the weldin circ it an input circ it (inclu in tran former win in s) there s al b

in ulatin material whic conforms to the values given in Ta le 5

Table 5 – Minimum dista c through ins lation

NOT Re uireme ts giv n in Ta le 5 are n t a plc ble to e uipme t with a s c n ary circ it c n e te to th

prote tiv c n u tor or wh re oth r pro isio s fom 6.4.2.3 to 6.4.2.9 are emplo e

If tran former metal c p rts are in ulated f rom grou d,

– the weldin circ it s al b electrical y isolated f rom the tran former metal c p rts by

double or reinforced in ulation in ac ordan e with 6.3 determined by the s p ly circ it

workin voltage; or

– the s p ly circ it s al b electrical y isolated f om the tran former metal c p rts by

double or reinf orced in ulation in ac ordan e with 6.3

If another circ it is con ected to the weldin circ it, the p wer of the other circ it s al b

s p l ed by a saf ety isolatin tran former or eq ivalent me n

If the weldin circ it is not con ected to the protective con u tor, the tou h c r ent b twe n

the weldin outlets an the protective con u tor terminal s al not ex e d 14 mA p ak

Co formity sh ll b c e k d b me sureme t a c rd ing to 6.2.6

6.4.2.3 Metal s re n betwe n win ings of the s pply circ it a d the welding circ it

Win in s of the s p ly circ it an the weldin circ it s al b in ulated by b sic in ulation to

a metal s re n betwe n them whic is con ected to the protective con u tor An example of

the stru ture is s own in Fig re 3

Figure 3 – Ex mple of metal s re n betwe n windings

of the s pply circ it a d the weldin circ it

The thic nes of the in ulation b twe n e c win in an the s re n s al b at le st half the

values given in Ta le 5

If tran former metal c p rts are in ulated f om grou d,

– the weldin circ it s al b electrical y isolated f rom the tran former metal c p rts by

double or reinf orced in ulation in ac ordan e with 6.3 determined by the s p ly-circ it

workin voltage; or

– the s p ly circ it s al b electrical y isolated f om the tran former metal c p rts by

double or reinf orced in ulation in ac ordan e with 6.3

If another circ it is con ected to the weldin circ it, the p wer of the other circ it s al b

s p l ed by a saf ety isolatin tran former or eq ivalent me n

If the weldin circ it is not con ected to the protective con u tor, the le kage c r ent

b twe n the weldin outlets an the protective con u tor terminal s al not ex e d 10 mA a.c

r.m.s

Co formity sh l l b c e k d b visu l insp ct ion a d b me sureme t a c rd ing to 6.4.2.2

6.4.2.4 Prote tiv con uctor conne te dire t to welding circ its

If workpieces are not in ulated fom the protective con u tor, the integrity of the main s p ly

s stems protective con u tor s ould o served

Figure 4 – Ex mple of prote tiv condu tor con e te dire tly

to the welding circ it (single-sp t, a.c c r e t e uipme t)

Figure 5 – Ex mple of prote tiv condu tor con e te dire tly

to welding circ its (multi-spot, a.c c r e t e uipme t)

Key

1 In erter

Figure 6 – Ex mple of prote tiv condu tor con e te dire tly

to welding circ its (me ium-f re u nc e uipme t)

Eac output circ it in lu in the win in s al b con ected direct to the protective con u tor

ac ordin to Fig res 4, 5 an 6, u les it cau es ex es ive circ lation c r ents in the

protective con u tor

If ex es ive circ lation c r ents a p ar, one of the me s res complyin with 6.4.2.5 to

6.4.2.8 can b u ed

Co formity sh l l b c e k d b visu l insp ct ion a d o eratio

6.4.2.5 Prote tiv cond ctor conne te through impe a c

Eac output circ it in lu in the win in s al b p rmanently con ected to the protective

con u tor by an imp dan e, ac ordin to Fig re 7, to l mit circ lation c r ents

The imp dan e s alI b so desig ed that, in the case of f aiure, the protective device f or the

input circ it, provided at in tal ation, o erates within the time sp cified in IEC 6 3 4-4-41

NOT Th imp d n e whie re u in th weldin c re t circ latin o th prote tiv c n u tor u d r n rmal

c n itio s als re u e th fa lt c re t Whie this imp d n e in T e rthin s stems c n b n glgible, in TN

e rthin s stems th a ditio al imp d n e c n a oid pro er o eratio of o erc re t dis o n ctin d vic s (ie

time s e ifie in IEC 6 3 4-4-41 c n b n t f ulf ile )

The protective imp dan e device s al with tan the thermal an electric stres es oc ur in

d rin the fai ure b f ore the protective device o erates

Co formity sh l l b c e k d b visu l insp ction a d a c rd in t o I EC 6 3 4-6

Figure 7 – Ex mple of prote tiv conductor conn cte

to weldin circ its throu h impe a ce

6.4.2.6 Prote tiv con uctor conne te through a to-in ucta c s

Eac output circ it in lu in the win in s al b p rmanently con ected to the protective

con u tor by a satura le auto-in u tan e, ac ordin to Fig re 8 or Fig re 9, to l mit

circ lation-c r ents

The imp dan e s alI b so desig ed that, in the case of a f aiure, the protective device f or the

input circ it, provided at in tal ation, o erates within the time sp cif ied in IEC 6 3 4-4-41

NOT Th imp d n e whie re u in th weldin c re t circ latin o th prote tiv c n u tor u d r n rmal

c n itio als re u e th fa lt c re t Whie this imp d n e in T e rthin s stems c n b n glgible, in TN

e rthin s stems th a ditio al imp d n e c n a oid pro er o eratio of o erc re t dis o n ctin d vic s (ie

time s e if i d in IEC 6 3 4-4-41 c n b n t f ulf ile )

The protective imp dan e device s al with tan the thermal an electric stres es oc ur in

d rin the fai ure b f ore the protective device o erates

Co formity sh l l b c e k d b visu l insp ction a d a c rd in t o I EC 6 3 4-6

Figure 8 – Ex mple of prote tiv conductor conne te

to welding circ its throug a to-inducta c s

Figure 9 – Ex mple of prote tiv conductor conn cte

to welding circ its throug a to-inducta c s

6.4.2.7 Cur e t operate re idual c r e t de ic

Eac output win in s al b p rmanently con ected to the protective con u tor direct or by

me n of a s ita le resistan e ac ordin to Fig re 10 or Fig re 1

The in tal ed resid al c r ent device (RCD) s al b an integral p rt of the eq ipment An

Key

1 In erter

Figure 1 – Ex mple of c r e t o erate RCD (me ium-f re ue c e uipme t)

RCD typ selection s al take care of the p s ible f ault c r ent wavef orm

RCD sen itivity selection req ires co rdination with the in talation e rth con ection; this may

b ac ieved by

– previou me s rement in the in talation place; or

– req irement in the in tru tion man al of a maximum al owed value of e rth con ection

resistan e; or

– u e of a hig -sen itivity RCD with a maximum I

∆n

value of 3 mA

Resistan e s al b dimen ioned to al ow RCD o eration f or every set-up of the eq ipment

within the time sp cified in IEC 6 3 4-4-41 The resistan e s al with tan the thermal an

electric stres es oc ur in d rin the f aiure b f ore the RCD o erates

Co formity sh ll b c e k d b visu l insp ct ion a d o erat io

6.4.2.8 Cur e t operate re idual c r e t de ic a d volta e rela

Saf ety is provided by b th the resid al c r ent device an a voltage relay (se Fig re 12)

The s stem is s ita le f or secon ary rectified s stems

The in tal ed RCD an voltage relay s al b an integral p rt of the eq ipment

NOT If e tif i rs are u e in th in ut circ it, a d.c c re t c mp n nt c n o c r in th c s of aiure This c n

RCD typ selection s al take care of the p s ible f ault c r ent wavef orm.

RCD sen itivity selection req ires co rdination with the in talation e rth con ection; this may

b ac ieved by

– previou me s rement in the in talation place; or

– req irement in the in tru tion man al of a maximum al owed value of e rth con ection

resistan e; or

– u e of a hig -sen itivity RCD with a maximum I

∆n

value of 3 mA

Resistan e s al b dimen ioned to al ow RCD o eration f or every set-up of the eq ipment

within the time sp cified in IEC 6 3 4-4-41 The resistan e s al with tan the thermal an

electric stres es oc ur in d rin the f aiure b f ore the RCD o erates

6.4.2.9 Cur e t operate re idual c r e t de ic a d s fety volta e rela

Saf ety is provided by b th an RCD an a safety voltage relay (se Fig re 13)

Eac output win in s al b p rmanently con ected to the saf ety voltage o erated relay

ac ordin to Fig re 13 A p sitive control ed circ it bre ker s al b u ed

To al ow the voltage relay to b saf e, it s al b provided with a control circ it as urin the

contin ity of the con ection to the secon ary con u tor, an as urin detection of p s ible

f ault to grou d of sen in wires

NOT 1 Ex mple of this ty e of c ntrol circ it is a d vic inje tin a c re t into a s n in circ it c mp s d of

two s p rate s n in wire , c ntin o sly c e kin th s n in circ it c ntin ity To e s re c re t o eratio , b th

s n in wire h v to b c n e te to th s me o tp t of th tra sf ormer

Con ection to the rectified output is not al owed as a tran former in ulation f ai ure may

damage the rectifier an avoid cor ect o eration

The in tal ed RCD an voltage safety relay s al b an integral p rt of the eq ipment

Co formity sh l l b c e k d b visu l insp ction a d o eratio

NOT 2 If e tif i rs are u e in th in ut circ it, a d.c c re t c mp n nt c n o c r in th c s of a faiure This

RCD typ selection s al take care of the p s ible f ault c r ent waveform

RCD sen itivity selection req ires co rdination with in tal ation e rth con ection; this may b

ac ieved by

– previou me s rement in the in talation place; or

– req irement in the in tru tion man al of a maximum al owed value of e rth con ection

resistan e; or

– u e of a hig -sen itivity RCD with a maximum I

∆n

value of 3 mA

Resistan e s al b dimen ioned to al ow RCD o eration f or every set-up of the eq ipment

within the time sp cified in IEC 6 3 4-4-41 The resistan e s al with tan the thermal an

electric stres es oc ur in d rin the f aiure b f ore the RCD o erates