Iec ts 61245 2015

I EC TS 61 245 ® Ed i ti on 201 5-03 TECH N I CAL SPECIFI CATI ON Arti fi ci al pol l u ti on tests on h i gh -vol tag e ceram i c an d gl ass i n su l ators to be u sed I EC TS 61 245: 201 5-03(en ) on d c system s TH I S P U B L I C ATI O N I S C O P YRI G H T P RO TE C T E D C o p yri g h t © I E C , G e n e va , S w i tze rl a n d Al l or ri g h t s by re s e rv e d an y e i th e r m ean s, I EC c o p y ri g h t yo u r I EC 3, or or l o ca l IEC C e n t l ru e de CH -1 1 I E C's h a ve U n l ess o t h e rwi s e e l e c t ro n i c or m em ber an N a ti o n a l e n q u i ry m em ber s p e c i fi e d , m e ch a n i ca l , abou t N a ti o n a l no p a rt i n cl u d i n g C o m m i tte e o b ta i n i n g C o m m i tte e th e p u b l i ca ti o n c o u n t ry a d d i ti o n a l fo r O ffi c e in o f th i s p h o to co p yi n g fu rt h e r ri g h t s an d o f th e to th i s re p ro d u c e d re q u e s t e r If wi t h o u t yo u h a ve pl ease or u ti l i z e d p e rm i s s i o n an y co n ta c t in in an y q u e s ti o n s th e fo rm wri t i n g fro m abou t a d d re s s I EC bel ow or i n fo rm a t i o n Te l : +41 22 91 02 1 F a x: +41 22 91 03 00 G e n e va i n fo @ i e c c h 20 be p u b l i ca ti o n , V a re m b é S wi t z e rl a n d may m i c ro fi l m , ww w i e c c h Ab ou t th e I E C Th e I n t e rn a t i o n a l I n t e rn a t i o n a l E l e c t ro t e c h n i c a l S t a n d a rd s fo r al l Com m i ssi on e l e c t ri c a l , (I E C) e l e c t ro n i c and is th e re l a t e d l ead i n g g l obal o rg a n i z a t i o n th a t p re p a re s an d pu bl i sh es te ch n o l o g i e s Ab o u t I E C p u b l i c a ti o n s Th e te c h n i ca l l a te s t e d i ti o n , co n te n t a of IEC c o rri g e n d a p u b l i ca ti o n s or an is ke p t amend ment u n d er might co n s ta n t h a ve been I E C C atal og u e - webs tore i ec ch /catal og u e Th e s ta n d - a l o n e b i b l i o g p h i ca l Te ch n i ca l a p p l i ca ti o n i n fo rm a ti o n on S p e ci fi ca ti o n s , d o cu m e n ts Ava i l a b l e fo r fo r I EC PC, M ac th e I n te rn a ti o n a l An d ro i d e n ti re S ta n d a rd s , Re p o rts OS , an d o th e r Ta b l e ts an d i Pad a d va n ce d va ri e ty of s e a rch en abl es cri te ri a co m m i tte e , … ) an d th e Th e wo rl d ' s e l e ctri ca l wi th d wn It to ( re fe re n ce al so g i ve s fi n d I EC i n fo rm a ti o n on Pl ease m a ke s u re th a t yo u h a ve th e d e fi n i ti o n s in a d d i ti o n a l on l i n e co n ta i n i n g En g l i sh an d l an g u ag es d i cti o n a ry m o re F re n ch , Al s o th a n wi th e l e ctro n i c 000 as th e an d te rm s e q u i va l e n t kn o wn Vo ca b u l a ry ( I E V) of 30 te rm s an d in I n te rn a ti o n a l on l i n e I E C G l os s ary - s td i ec ch /g l os s ary p u b l i ca ti o n s n u m b e r, I E C l ead i n g te rm s E l e ctro te ch n i ca l I E C pu bl i cati on s s earch - www i ec ch /s earch pu b Th e by E l ectroped i a - www el ectroped i a org co n s u l ti n g Te ch n i ca l re v i e w pu bl i sh ed te xt, by a te ch n i ca l p ro j e cts , re p l a ce d M o re th a n E n g l i sh cl a u s e h a ve p u b l i ca ti o n s 77, 60 an d of I EC been 86 an d 000 F re n ch e l e ctro te ch n i ca l e xtra cte d p u b l i ca ti o n s co l l e cte d fro m fro m i ssu ed e a rl i e r te rm i n o l o g y th e Te rm s s i n ce an d 2002 p u b l i ca ti o n s e n tri e s S om e of in D e fi n i ti o n s I EC e n tri e s TC 37, C I S P R I E C J u s t P u bl i s h ed - webs tore i ec ch /j u s u bl i s h ed S ta y up d e ta i l s al so to al l o n ce d a te n ew a on al l n ew p u b l i ca ti o n s m o n th by em l I EC p u b l i ca ti o n s re l e a s e d J u st Ava i l a b l e Pu bl i sh ed on l i n e an d I E C C u s to m er S ervi ce C en tre - web s tore i ec ch /cs c If yo u n eed wi s h fu rth e r C e n tre : to g i ve us a s s i s ta n ce , cs c@ i e c ch yo u r fe e d b a ck pl ease co n ta ct on th e th i s p u b l i ca ti o n or C u s to m e r S e rvi ce I E C TS 61 45 ® Ed i ti on 201 5-03 TE C H N I C AL S PE C I FI C ATI ON Arti fi ci al pol l u ti on tests on h i g h -vol tag e ceram i c an d g l ass i n su l ators to be u s ed on d c system s I N TERN ATI ON AL ELECTROTECH N I CAL COM M I SSI ON I CS 29 080 I SBN 978-2 -832 2-2546-2 Warn i n g ! M ake s u re th at you obtai n ed th i s pu bl i cati on from an au th ori zed d i stri bu tor ® Reg i stered trad em ark of th e I n tern ati on al El ectrotech n i cal Com m i ssi on –2– CONTENTS IEC TS 61 245:201 © IEC 201 FOREWORD INTRODUCTION Scope Normative references Terms and definitions General test requirements 1 4.1 General 1 4.2 Test methods 4.3 Arrangement of insulator for test 4.3.1 Test configuration 4.3.2 Insulator cleaning 4.4 Requirements for the test circuit 4.4.1 Test voltage 4.4.2 Atmospheric corrections 4.4.3 Characteristics of the measuring systems 4.4.4 Identification of flashover Salt fog method 5.1 General information 5.2 Salt solution 5.3 Spraying system 5.4 Conditions before starting the test 5.5 Preconditioning process 5.6 Withstand test 20 5.7 Acceptance criteria for the withstand test 20 Solid layer method 20 6.1 General information 20 6.2 Main characteristics of inert materials 21 6.3 Composition of the contaminating suspension 21 6.4 Application of the pollution layer 22 6.5 Determination of the degree of pollution of the test insulator 23 6.6 Test procedure 23 6.7 Withstand test and acceptance criteria 24 Annex A (informative) Method for checking the uniformity of the layer 25 Annex B (informative) Determination of the withstand characteristics of insulators 27 B.1 General 27 B.2 Determination of the maximum withstand degree of pollution at a given test voltage 27 B.3 Determination of the maximum withstand voltage at a given degree of pollution 27 B.4 Determination of the 50 % withstand voltage at a given degree of pollution 28 Annex C (informative) Additional recommendations concerning the solid layer method procedures 29 C.1 General 29 C.2 Contamination practice 29 C.3 Drying of the pollution layer 29 C.4 Checking the wetting action of the fog 29 I E C TS 5: © I E C 01 C – – C h e cki n g fo g u n i fo rm i ty fo r l a rg e o r co m p l e x te s t o b j e cts C F o g i n p u t to th e te s t ch a m b e r C D u ti o n o f th e wi th s ta n d te s t C E va l u a ti o n o f th e re fe re n ce s a l t d e p o s i t d e n s i ty ( SDD ) An n e x D ( i n fo rm a ti ve ) I n fo rm a ti o n to ch e ck e q u i p m e n t fo r a rti fi ci a l p o l l u ti o n te s ts An n e x E ( i n fo rm a ti ve ) S u p p l e m e n ta ry i n fo rm a ti o n o n a rti fi ci a l p o l l u ti o n te s ts o n i n s u l a to rs fo r vo l ta g e s ys te m s E of ± 0 kV a n d a b o ve ( s o l i d l a ye r m e th o d p ro ce d u re B ) G e n e l E T e s t ch a m b e r E F o g g e n e to r E We tti n g a cti o n a n d u n i fo rm i ty o f fo g d e n s i ty E T e s t o f ve ry l a rg e i n s u l a to rs An n e x F ( i n fo rm a ti ve ) F u rth e r i n ve s ti g a ti o n B i b l i o g p h y F i g u re – Ri p p l e a m p l i tu d e a n d a ctu a l m e a n vo l ta g e , m e a s u re d o n a re s i s ti ve l o a d a b s o rb i n g 0 m A F i g u re – Vo l ta g e d ro p a n d vo l ta g e o ve rs h o o t a n d l e a ka g e cu rre n t F i g u re – Va l u e o f fa cto r b ve rs u s s o l u ti o n te m p e tu re θ F i g u re – Typ i ca l co n s tru cti o n o f fo g s p y n o z zl e F i g u re – Te s t l a yo u t fo r i n cl i n e d i n s u l a to rs F i g u re A – Arra n g e m e n t o f th e p ro b e e l e ctro d e s F i g u re A – C i rcu i t d i a g m o f th e m e te r F i g u re C – D e te rm i n a ti o n o f l a ye r co n d u cta n ce a n d e va l u a ti o n o f i ts ri s e ti m e – t1 T t c = 31 Ta b l e – S a l t- fo g m e th o d : co rre s p o n d e n ce b e twe e n th e va l u e o f s a l i n i ty a n d vo l u m e co n d u cti vi ty o f th e s o l u ti o n a t a te m p e tu re o f ° C Ta b l e – M a i n ch a cte ri s ti cs o f th e i n e rt m a te ri a l s u s e d i n s o l i d l a ye r s u s p e n s i o n s Ta b l e – Ka o l i n ( o r To n o ko ) co m p o s i ti o n : a p p ro xi m a te co rre s p o n d e n ce b e twe e n th e re fe re n ce d e g re e s o f p o l l u ti o n o n th e i n s u l a to r a n d th e vo l u m e co n d u cti vi ty o f th e s u s p e n s i o n a t a te m p e tu re o f ° C 2 Ta b l e D – ( P ro vi s i o n a l ) 3 – – I E C TS : © I E C I N TE RN ATI O N AL E L E C TRO TE C H N I C AL C O M M I S S I O N ARTI F I C I AL P O LLU TI O N TE S TS O N H I G H -VO LTAG E C E RAM I C AN D G LAS S I N S U LATO RS TO B E U S E D O N D C S YS TE M S F O RE WO RD 1) T h e I n t e rn a ti o n a l E l e c tro te c h n i c a l C o m m i s s i o n ( I E C ) i s a wo rl d wi d e o rg a n i z a t i o n fo r s ta n d a rd i z a ti o n c o m p ri s i n g all n a ti o n a l e l e c tro te c h n i c a l c o m m i tte e s (I E C N a ti o n a l C o m m i t te e s ) Th e o b j e ct of IEC is to p ro m o te i n t e rn a ti o n a l c o - o p e ti o n o n a l l q u e s ti o n s c o n c e rn i n g s ta n d a rd i z a ti o n i n th e e l e c tri c a l a n d e l e c tro n i c fi e l d s T o th i s end an d Te ch n i ca l in a d d i ti o n R e p o rts , to o th e r a c ti v i ti e s , P u b l i cl y Av a i l a b l e IEC pu bl i sh es S p e c i fi c a t i o n s I n te rn a t i o n a l ( P AS ) an d S ta n d a rd s , Gu i d es Te ch n i ca l ( h e re a fte r S p e c i fi c a ti o n s , re fe rre d to as “I EC P u b l i c a ti o n ( s ) ” ) T h e i r p re p a t i o n i s e n t ru s te d to te c h n i c a l c o m m i t te e s ; a n y I E C N a ti o n a l C o m m i tt e e i n te re s te d in th e s u b j e ct d eal t wi th may p a rti c i p a t e in th i s p re p a to ry wo rk I n t e rn a ti o n a l , g o v e rn m e n ta l and n on - g o v e rn m e n ta l o rg a n i z a t i o n s l i a i s i n g wi th t h e I E C a l s o p a rti c i p a te i n t h i s p re p a ti o n I E C c o l l a b o te s c l o s e l y wi t h th e I n te rn a t i o n a l O rg a n i z a ti o n fo r S t a n d a rd i z a t i o n (I SO) in a c c o rd a n c e wi t h c o n d i ti o n s d e te rm i n e d by a g re e m e n t b e twe e n th e two o rg a n i z a ti o n s 2) T h e fo rm a l d e ci s i o n s o r a g re e m e n ts o f I E C o n t e c h n i c a l m a tte rs e xp re s s , a s n e a rl y a s p o s s i b l e , a n i n t e rn a ti o n a l co n s e n s u s of opi ni on on th e re l e v a n t s u b j e c ts s i n ce e a ch te ch n i ca l c o m m i tt e e h as re p re s e n t a ti o n fro m all i n te re s te d I E C N a ti o n a l C o m m i tt e e s 3) I E C P u b l i c a ti o n s h a v e th e fo rm C o m m i tte e s i n th a t s e n s e P u b l i c a ti o n s is a c c u te , o f re c o m m e n d a ti o n s fo r i n te rn a ti o n a l u se an d a re a c ce p te d b y I E C N a ti o n a l W h i l e a l l re a s o n a b l e e ffo rts a re m a d e to e n s u re t h a t th e te c h n i c a l c o n te n t o f I E C IEC can n o t be h el d re s p o n s i b l e fo r th e wa y in wh i c h th e y a re used or fo r an y m i s i n te rp re ta ti o n b y a n y e n d u s e r 4) In o rd e r to p ro m o te tra n s p a re n tl y to i n t e rn a ti o n a l th e m a xi m u m u n i fo rm i ty, e xte n t IEC possi bl e in N a ti o n a l th ei r C o m m i tte e s n a ti o n a l an d u n d e rta k e re g i o n a l to appl y IEC p u b l i c a ti o n s P u b l i c a ti o n s An y d i v e rg e n c e b e twe e n a n y I E C P u b l i c a t i o n a n d th e c o rre s p o n d i n g n a ti o n a l o r re g i o n a l p u b l i c a t i o n s h a l l b e c l e a rl y i n d i c a t e d i n th e l a tte r 5) I E C i ts e l f d o e s n o t p ro v i d e a n y a tte s ta ti o n o f c o n fo rm i ty a s s e s s m e n t s e rv i c e s a n d , i n s o m e a re a s , I n d e p e n d e n t c e rt i fi c a ti o n b o d i e s p ro vi d e c o n fo rm i ty a c c e s s t o I E C m a rks o f c o n fo rm i t y I E C i s n o t re s p o n s i b l e fo r a n y s e rv i c e s c a rri e d o u t b y i n d e p e n d e n t c e rti fi c a ti o n b o d i e s 6) Al l u s e rs s h o u l d e n s u re th a t th e y h a v e th e l a te s t e d i ti o n o f th i s p u b l i c a ti o n 7) N o l i a b i l i ty s h a l l a tta c h to I E C o r i ts d i re c t o rs , e m p l o ye e s , s e rv a n ts o r a g e n ts i n c l u d i n g i n d i v i d u a l e xp e rts a n d m e m b e rs o f i ts te c h n i c a l c o m m i tte e s a n d I E C N a ti o n a l C o m m i tt e e s fo r a n y p e rs o n a l i n j u ry, p ro p e rty d a m a g e o r o th e r d a m a g e e xp e n s e s of any a ri s i n g ou t n a tu re wh a ts o e v e r, wh e t h e r d i re ct of p u b l i c a ti o n , use th e o f, or o r i n d i re ct , re l i a n c e u pon , o r fo r c o s ts th i s IEC (i n cl u d i n g P u b l i c a ti o n or l eg al fe e s ) an d any o th e r I EC P u b l i c a ti o n s 8) At te n t i o n i s d wn t o th e n o rm a ti v e re fe re n c e s c i te d i n t h i s p u b l i c a ti o n U s e o f th e re fe re n c e d p u b l i c a ti o n s i s i n d i s p e n s a b l e fo r th e c o rre c t a p p l i ca ti o n o f th i s p u b l i c a ti o n 9) At te n t i o n i s d wn t o t h e p o s s i b i l i ty th a t s o m e o f t h e e l e m e n ts o f t h i s I E C P u b l i c a ti o n m a y b e t h e s u b j e c t o f p a te n t ri g h ts I E C s h a l l n o t b e h e l d re s p o n s i b l e fo r i d e n ti fyi n g a n y o r a l l s u c h p a te n t ri g h ts Th e main ta s k of I EC te ch n i ca l co m m i tte e s is to p re p a re I n te rn a ti o n a l S ta n d a rd s In e xce p ti o n a l ci rcu m s ta n ce s , a te ch n i ca l co m m i tte e m a y p ro p o s e th e p u b l i ca ti o n o f a te ch n i ca l s p e ci fi ca ti o n wh e n • th e re q u i re d s u p p o rt ca n n o t b e o b ta i n e d fo r th e p u b l i ca ti o n o f a n I n te rn a ti o n a l S ta n d a rd , d e s p i te re p e a te d e ffo rts , o r • th e s u b j e ct i s s ti l l u n d e r te ch n i ca l d e ve l o p m e n t o r wh e re , fo r a n y o th e r re a s o n , th e re i s th e fu tu re b u t n o i m m e d i a te p o s s i b i l i ty o f a n a g re e m e n t o n a n I n te rn a ti o n a l S ta n d a rd Te ch n i ca l s p e ci fi ca ti o n s a re s u b j e ct to re vi e w wi th i n th re e ye a rs o f p u b l i ca ti o n to d e ci d e wh e th e r th e y ca n b e tra n s fo rm e d i n to I n te rn a ti o n a l S ta n d a rd s I EC TS 61 245, wh i ch is a te ch n i ca l s p e ci fi ca ti o n , h as been p re p a re d by I EC te ch n i ca l co m m i tte e : I n s u l a to rs Th i s s e co n d e d i ti o n ca n ce l s and co n s ti tu te s a te ch n i ca l re vi s i o n re p l a ce s th e fi rs t e d i ti o n pu blish ed in 993 Th i s e d i ti o n I E C TS 5: © I E C 01 – – Th i s e d i ti o n i n cl u d e s th e fo l l o wi n g s i g n i fi ca n t te ch n i ca l ch a n g e s wi th re s p e ct to th e p re vi o u s e d i ti o n : a) C o rre cti o n s a n d th e a d d i ti o n o f e xp l a n a to ry m a te ri a l ; b) Th e a d d i ti o n o f C l a u s e o n a tm o s p h e ri c co rre cti o n ; c) Th e ch a n g e o f u p p e r l i m i t o f vo l u m e co n d u cti vi ty o f ta p wa te r fo r i n s u l a to r cl e a n i n g to , S /m ; d) Th e e xte n s i o n to U H V vo l ta g e s ; a n d e) Th e a d d i ti o n o f An n e x B " D e te rm i n a ti o n o f th e wi th s ta n d ch a cte ri s ti cs o f i n s u l a to rs " a n d An n e x E " S u p p l e m e n ta ry i n fo rm a ti o n o n a rti fi ci a l p o l l u ti o n te s ts o n i n s u l a to rs fo r vo l ta g e s ys te m s of ± 0 kV a n d a b o ve ( s o l i d l a ye r m e th o d p ro ce d u re B ) Th e te xt o f th i s te ch n i ca l s p e ci fi ca ti o n i s b a s e d o n th e fo l l o wi n g d o cu m e n ts : E n q u i ry d ft R e p o rt o n vo ti n g /3 /D T S /3 /R V C F u l l i n fo rm a ti o n o n th e vo ti n g fo r th e a p p ro va l o f th i s te ch n i ca l s p e ci fi ca ti o n ca n b e fo u n d i n th e re p o rt o n vo ti n g i n d i ca te d i n th e a b o ve ta b l e Th i s p u b l i ca ti o n h a s b e e n d fte d i n a cco rd a n ce wi th th e I S O /I E C D i re cti ve s , P a rt Th e co m m i tte e h a s d e ci d e d th a t th e co n te n ts o f th i s p u b l i ca ti o n wi l l re m a i n u n ch a n g e d u n ti l th e s ta b i l i ty d a te i n d i ca te d on th e I EC we b s i te u nd er " h ttp : //we b s to re i e c ch " re l a te d to th e s p e ci fi c p u b l i ca ti o n At th i s d a te , th e p u b l i ca ti o n wi l l b e • tra n s fo rm e d i n to a n I n te rn a ti o n a l s ta n d a rd , • re co n fi rm e d , • wi th d wn , • re p l a ce d b y a re vi s e d e d i ti o n , o r • amend ed A b i l i n g u a l ve rs i o n o f th i s p u b l i ca ti o n m a y b e i s s u e d a t a l a te r d a te in th e d a ta – – I E C TS : © I E C I N TRO D U C TI O N Th e e l e ctri ca l s tre n g th o f d c i n s u l a ti o n u n d e r p o l l u ti o n co n d i ti o n s d e te rm i n e s , i n m a n y ca s e s , th e d i m e n s i o n s a n d th e d e s i g n o f th e i n s u l a ti o n Th e d c te s t p ro ce d u re s a s s p e ci fi e d i n th i s te ch n i ca l s p e ci fi ca ti o n fo l l o w cl o s e l y th e o n e s e s ta b l i s h e d fo r a c b y I E C Th i s d o e s n o t e xcl u d e th e p o s s i b i l i ty th a t a t a l a te r ti m e o th e r d c te s t p ro ce d u re s wi l l b e d e fi n e d Th e m a i n d i ffe re n ce s b e twe e n th i s te ch n i ca l s p e ci fi ca ti o n a n d I E C a re : – te s t ci rcu i t re q u i re m e n ts i n cl u d e ri p p l e fa cto r, vo l ta g e d ro p and vo l ta g e o ve rs h o o t No re q u i re m e n ts a re m a d e fo r th e m i n i m u m s h o rt ci rcu i t cu rre n t o r ti o b e twe e n s h o rt ci rcu i t a n d l e a ka g e cu rre n ts ; – – d i ffe re n t cri te ri a fo r th e i d e n ti fi ca ti o n o f fl a s h o ve r a re g i ve n ; fo r th e sal t fo g te s t, a p re - co n d i ti o n i n g p ro ce s s wi th d c vo l ta g e may be u sed by a g re e m e n t; – th e we tti n g te , th e r th a n th e s te a m i n j e cti o n te , i s p re s cri b e d ; th e m e a s u re m e n t o f th e l a ye r co n d u cta n ce i s u s e d to ch e ck th e we tti n g a cti o n o f th e fo g ; – a s re g a rd s th e s o l i d l a ye r m e th o d s , o n l y th e te s t p ro ce d u re typ e " B " i s co n s i d e re d d u e to th e h i g h s ca tte r o f th e re s u l ts o b ta i n e d wi th te s ts ca rri e d o u t a cco rd i n g to th e typ e " A" p ro ce d u re Th e te s ts a re d e e m e d to b e n o t a s u i ta b l e m e a s u re to p ro ve th e i n s u l a ti o n p e rfo rm a n ce o f p o l ym e ri c o r s p e ci a l typ e s o f i n s u l a to rs ( e g i n s u l a to rs wi th s e m i co n d u cti n g g l a ze o r co ve re d wi th a n y o rg a n i c i n s u l a ti n g m a te ri a l ) u n d e r p o l l u te d co n d i ti o n s Th e te s t p ro ce d u re s g i ve n i n th i s s ta n d a rd d o n o t ta ke a cco u n t o f th e d i ffe re n t p ro p e rti e s o f i n s u l a to rs s u ch a s s u rfa ce h yd ro p h o b i ci ty a n d h yd ro p h o b i ci ty tra n s fe r th ro u g h th e p o l l u ti o n l a ye r e tc Th e s e q u e s ti o n s a re u n d e r co n s i d e ti o n b y C I G RE S C D F o r th e te s t m e th o d s d e s cri b e d in th i s te ch n i ca l s p e ci fi ca ti o n , i t i s re co m m e n d e d th a t th e vo l ta g e fo r th e wi th s ta n d vo l ta g e te s ts b e s p e ci fi e d a s th e h i g h e s t va l u e o f o p e ti n g vo l ta g e wh i ch o ccu rs u n d e r n o rm a l o p e ti n g co n d i ti o n s O th e r te s t vo l ta g e s m a y b e a g re e d u p o n I f n o t o th e rwi s e s p e ci fi e d a n d a g re e d b e twe e n th e p a rti e s , vo l ta g e o f th e n e g a ti ve p o l a ri ty wi l l be appl ied O n l y th o s e te s t m e th o d s in wh i ch th e vo l ta g e is held co n s ta n t d u ri n g th e wh o l e te s t a re co n s i d e re d s u i ta b l e fo r s ta n d a rd i za ti o n Va ri a n ts i n wh i ch th e vo l ta g e i s i s e d co n ti n u o u s l y to fl a s h o ve r a re n o t i n cl u d e d i n th i s te ch n i ca l s p e ci fi ca ti o n Th e l e a ka g e cu rre n t m a y b e u s e d fo r i n te rp re ta ti o n o f th e te s t re s u l ts , an d th e re fo re i t i s re co m m e n d e d th a t th i s cu rre n t b e co n ti n u o u s l y m e a s u re d d u ri n g th e a rti fi ci a l p o l l u ti o n te s ts To a ch i e ve re p e a ta b l e re s u l ts , th e a rti fi ci a l l a ye r fo r d c p o l l u ti o n te s ts s h o u l d b e a s u n i fo rm a s p o s s i b l e , s i n ce n o n - u n i fo rm i ty ca n i n fl u e n ce d c wi th s ta n d a n d fl a s h o ve r vo l ta g e s Th e amou n t of n on -sol u bl e m a te ri a l on th e i n s u l a to r s u rfa ce may a ffe ct th e te s t re s u l ts Al th o u g h th i s m a tte r i s u n d e r co n s i d e ti o n a n d n o re q u i re m e n ts ca n b e g i ve n , th e d e fi n i ti o n of n on -sol u bl e d eposi t d e n s i ty has been i n tro d u ce d i n to th i s te ch n i ca l s p e ci fi ca ti o n fo r re fe re n ce Th e typ e an d q u a n ti ty of n on -sol u bl e m a te ri a l , th e s te a m te and th e p re co n d i ti o n i n g p ro ce d u re wi th s a l t fo g ( e i th e r b y a c o r d c vo l ta g e ) m a y a ffe ct th e te s t re s u l ts I E C TS 5: © I E C 01 Th e s ta n d a rd ( a l ti tu d e ≤ re s u l ts 000 m) a re i n te n d e d – – as re s u l ts Te s t re s u l ts o b ta i n e d o b ta i n e d in l a b o to ri e s a t h i g h e r a l ti tu d e o r i n s ta n d a rd a i r d e n s i ti e s a re to b e co rre cte d fo r a i r d e n s i ty sea l e ve l te s t ch a m b e rs wi th cl o s e to n on - – – I E C TS : © I E C ARTI F I C I AL P O LLU TI O N TE S TS O N H I G H -VO LTAG E C E RAM I C AN D G LAS S I N S U LATO RS TO B E U S E D O N D C S YS TE M S Scope Th i s te ch n i ca l s p e ci fi ca ti o n is a p p l i ca b l e fo r th e d e te rm i n a ti o n of th e d c wi th s ta n d ch a cte ri s ti cs o f ce m i c a n d g l a s s i n s u l a to rs to b e u s e d o u td o o rs a n d e xp o s e d to p o l l u te d ±1 a tm o s p h e re s , o n d c s ys te m s wi th th e h i g h e s t vo l ta g e o f th e s ys te m g re a te r th a n Th ese te s ts a re n o t a p p l i ca b l e typ e s o f i n s u l a to rs ( e g to p o l ym e ri c i n s u l a to rs , i n s u l a to rs wi th s e m i co n d u cti n g to g re a s e d g l a ze i n s u l a to rs o r co ve re d 0 V o r to s p e ci a l wi th a n y o rg a n i c i n s u l a ti n g m a te ri a l ) T h e o b j e ct o f th i s te ch n i ca l s p e ci fi ca ti o n i s to p re s cri b e p ro ce d u re s fo r a rti fi ci a l p o l l u ti o n te s ts a p p l i ca b l e to i n s u l a to rs fo r o ve rh e a d l i n e s , s u b s ta ti o n s a n d tra cti o n l i n e s a n d to b u s h i n g s It may al so fl a s h o ve r In be appl i ed a p p l yi n g to h ol l ow th e s e i n s u l a to rs p ro ce d u re s to wi th s u i ta b l e a p p a tu s p re ca u ti o n s i n co rp o ti n g to h ol l ow a vo i d i n te rn a l i n s u l a to rs , th e re l e va n t te ch n i ca l co m m i tte e s s h o u l d co n s i d e r th e i r e ffe ct o n a n y i n te rn a l e q u i p m e n t a n d th e s p e ci a l p re ca u ti o n s wh i ch m a y b e n e ce s s a ry N o rm a ti ve re fe re n ce s Th e fo l l o wi n g d o cu m e n ts , i n wh o l e o r i n p a rt, a re n o rm a ti ve l y re fe re n ce d i n th i s d o cu m e n t a n d a re i n d i s p e n s a b l e fo r i ts a p p l i ca ti o n F o r d a te d re fe re n ce s , o n l y th e e d i ti o n ci te d a p p l i e s F o r u n d a te d re fe re n ce s , th e l a te s t e d i ti o n of th e re fe re n ce d d o cu m e n t ( i n cl u d i n g an y a m e n d m e n ts ) a p p l i e s I E C TS 81 5-1 , Se le ctio n p o llute d co n ditio n s – and Pa rt : dim e n s io n in g D e fin itio n s , of h ig h -vo lta ge in fo rm a tio n in s ula to rs I E C 60 06 0-1 , High -vo lta ge te s t te ch n iq ue s – Pa rt : G e n e l de fin itio n s I E C 60 06 0-2 , High -vo lta ge te s t te ch n iq ue s – Pa rt 2: Me a s urin g s ys te m s in te n de d fo r us e in a n d ge n e l p rin cip le s a n d te s t re q uire m e n ts Te rm s a n d d e fi n i ti o n s F o r th e p u rp o s e o f th i s te ch n i ca l s p e ci fi ca ti o n , th e fo l l o wi n g te rm s a n d d e fi n i ti o n s a p p l y i n d i vi d u a l te s t o n e s i n g l e p ro ce s s co n s i s ti n g i n a p p l yi n g to th e o b j e ct a s p e ci fi e d te s t vo l ta g e , fo r a s p e ci fi e d ti m e o r u n ti l fl a s h o ve r o ccu rs , a t a s p e ci fi e d d e g re e o f p o l l u ti o n a ctu a l m e a n vo l ta g e U a m ean va l u e co n s i d e re d of an d th e vo l ta g e h a vi n g a at a g i ve n d u ti o n i n s ta n t eq u al to o ve r th a t of a ti m e on e i n te rva l cycl e of en d i n g th e at th e a l te rn a ti n g i n s ta n t vo l ta g e s u p p l yi n g th e re cti fi e r N o t e to e n try: W h e n i t i s n o t p o s s i b l e to d e te rm i n e th e c yc l e o f th e s u p p l y v o l ta g e , th e ti m e i n te rv a l i s m s – 24 – I E C TS : © I E C S te a m fo g s h a l l b e u s e d fo r we tti n g th e l a ye r Th e te s t o b j e ct s h a l l be we tte d by m ean s o f fo g g e n e to rs wh i ch p ro vi d e a u n i fo rm fo g d i s tri b u ti o n a ro u n d a n d o ve r th e wh o l e l e n g th o f th e te s t o b j e ct Th e te m p e tu re o f th e te s t o b j e ct a t th e b e g i n n i n g o f th e we tti n g s h a l l b e wi th i n K o f th e a m b i e n t te m p e tu re i n th e te s t ch a m b e r N O TE T h e s te a m c a n b e g e n e t e d b y d i ffe re n t m e th o d s , e g b o i l e rs i n s i d e th e t e s t ch a m b e r o r s t e a m g e n e to r o u t s i d e t h e t e s t c h a m b e r wi t h d i s tri b u ti o n i n s i d e th e t e s t c h a m b e r b y s u i t a b l e t u b e s wi th h o l e s Th e fo g g e n e ti o n i n th e te s t ch a m b e r s h a l l b e m a i n ta i n e d u n ti l th e e n d o f th e i n d i vi d u a l te s t a t a co n s ta n t s te a d y te o f fl o w Th e fo g g e n e ti o n s h a l l b e u n d e r th e te s t o b j e ct a s cl o s e a s p o s s i b l e to th e fl o o r l e ve l I n a n y ca s e th e y s h a l l b e a t l e a s t m a wa y fro m th e te s t o b j e ct a n d th e i r fl o w s h a l l n o t b e d i re cte d to wa rd s i t ( s e e a l s o C l a u s e C ) A p l a s ti c te n t s u rro u n d i n g th e te s t o b j e ct m a y b e u s e d to l i m i t th e vo l u m e o f th e te s t ch a m b e r wi th o u t i n fl u e n ci n g , h o we ve r, th e p a tte rn o f th e fo g d e ve l o p m e n t a ro u n d th e i n s u l a to r N O TE I f a p l a s ti c t e n t i s u s e d , i t c a n b e u s e fu l to c h e c k th e we tti n g e ffi c i e n c y b y d u m m y i n s u l a to r ( s e e C l a u s e C 5) Th e s te a m i n pu t te in th e ch a m b e r sh al l be z e ro u n ti l th e te s t vo l ta g e is appl i ed and m a i n ta i n e d co n s ta n t th e re a fte r At n o rm a l a m b i e n t te m p e tu re , th e n o m i n a l s te a m i n p u t te of (0, 05 ± , ) kg /h per cu b i c m e tre of th e te s t ch a m b e r vo l u m e n o rm a l l y p ro vi d e s th e re q u i re d we tti n g te I n ca s e s o f ve ry l o w o r h i g h o u td o o r te m p e tu re , e s p e ci a l l y wi th p o o r th e rm a l i n s u l a ti o n o f th e ch a m b e r, h i g h a l ti tu d e , o r th e p re s e n ce o f tu rb u l e n ce i n th e ch a m b e r, a d i re ct ch e ck o f th e we tti n g a cti o n o f th e fo g m a y b e re q u i re d a s d e s cri b e d i n C l a u s e C a n d a cco rd i n g to th e ch e cki n g re s u l ts th e n e ce s s a ry s te a m i n p u t te m a y b e d i ffe re n t N O TE F o r th e d e te rm i n a ti o n o f th e s te a m te , o n e o f th e fo l l o wi n g m e t h o d s c a n b e u s e d : – p o we r m e a s u re m e n ts fo r s te a m fo g g e n e ti o n ; – m e a s u re m e n t o f t h e a m o u n t o f wa te r u s e d fo r s t e a m g e n e ti o n i n a n i n d i v i d u a l te s t N O TE T h e we t ti n g a c ti o n o f th e fo g wi l l b e a ffe c te d b y t h e a b s o l u te h u m i d i ty a n d c o n d e n s a ti o n o n th e wa l l s F o r ve ry l a rg e te s t o b j e cts u n i fo rm we tti n g o f th e l a ye r m a y b e d i ffi cu l t to a ch i e ve I n s u ch ca s e s th e p ro ce d u re d e s cri b e d i n C l a u s e C m a y b e u s e d to ch e ck fo g u n i fo rm i ty Th e te s t vo l ta g e i s m a i n ta i n e d u n ti l fl a s h o ve r o ccu rs O th e rwi s e i t i s m a i n ta i n e d fo r 0 m i n fro m th e s ta rt o f th e te s t o r u n ti l th e ri s k o f fl a s h o ve r i s j u d g e d n e g l i g i b l e b y m e a s u re m e n t o f th e l e a ka g e cu rre n t o r o th e r te ch n i q u e s M o re d e ta i l e d i n fo rm a ti o n i s g i ve n i n C l a u s e C Th e p o l l u ti o n l a ye r ca n b e u s e d o n l y o n ce Wi th s ta n d te s t a n d a c c e p t a n c e c ri t e ri a Th e o b j e ct o f th i s te s t i s to co n fi rm th e s p e ci fi e d wi th s ta n d d e g re e o f p o l l u ti o n a t th e s p e ci fi e d te s t vo l ta g e Th e s p e ci fi e d ch a cte ri s ti cs o f th e i n s u l a to rs a re co n fi rm e d if no fl a s h o ve r o ccu rs d u ri n g th re e co n s e cu ti ve i n d i vi d u a l te s ts p e rfo rm e d i n a cco rd a n ce wi th I f o n l y o n e fl a s h o ve r o ccu rs , a fo u rth te s t s h a l l b e p e rfo rm e d a n d th e i n s u l a to r th e n p a s s e s th e te s t i f n o fu rth e r fl a s h o ve r o ccu rs IEC TS 61 245:201 © IEC 201 – 25 – (informative) An n e x A M e t h o d fo r c h e c ki n g t h e u n i fo rm i t y o f t h e l a ye r The device for checking the uniformity of the wet layer on an insulator surface basically consists of a probe and a meter As an indication a possible arrangement of such a device is described as follows: – Probe (Figure A.1 ) Two spherical stainless steel electrodes, mm diameter and mm between centres, overhanging from the probe shall be pressed against the insulator surface A constant surface pressure is obtained by means of a spring mechanism developing a force of about N – Meter (Figure A.2) A voltage source stabilized by a Zener-diode at 6,8 V supplies the current across the electrodes and the surface between them The measuring instrument with a full scale deflection at 50 µ A is protected by a diode in parallel Measurements shall be carried out at different points of the insulator surface The polarization effect shall be taken into account by a momentary operation of the meter push-button The uniformity of the layer is deemed acceptable when the difference between each of the measurements and their average, as a percentage of the average value, does not exceed the limits ± 30 % 5 Dimensions in millimetres 14 F i g u re A IEC – A rra n g e m e n t o f t h e p ro b e e l e c t ro d e s – 26 – I EC TS 61 245: 201 © I EC C a l i b t i o n 6, Ω 200 Ω Ω k k Ω Ω V 330 P ro b e Ω e l e ct ro d e s M e a s u ri n g n g e M e a s u ri n g C h a rg i n g I n t e rn a l S µ 500 µ 00 S Ω µ 00 S V 50 000 3, 27 Ω 6, 35 237 k Ω i n s t ru m e n t 32, 200 M e a s u ri n g s e l e cto r i n s tru m e n t t e 50 µ re s i s t a n c e A , k Ω F i g u re A – C i rc u i t d i a g m o f t h e m e t e r IEC 201 I E C TS 5: © I E C 01 – 27 – An n e x B ( i n fo rm a ti ve ) D e t e rm i n a ti o n o f th e wi t h s t a n d c h a c t e ri s ti c s o f i n s u l a to rs B.1 G e n e l C l a u s e s a n d d e a l wi th th e ve ri fi ca ti o n o f th e s p e ci fi e d wi th s ta n d d e g re e o f p o l l u ti o n , a t th e s p e ci fi e d te s t d e te rm i n e d d i s ta n ce s o f th e m e a s u re d d i ffe re n t vo l ta g e In a d d i ti o n , h o we ve r, o ve r a n g e o f vo l ta g e , at i n s u l a to r i ts e l f d i ffe re n t d e g re e s of vo l ta g e p o l l u ti o n o r, To d o l e ve l s in th i s , or va l u e s th e ch a cte ri s ti cs o th e r wo rd s , th e th e m a xi m u m m a xi m u m E xa m p l e s of of an i n s u l a to r ca n be o ve r a n g e o f s p e ci fi c cre e p a g e wi th s ta n d wi th s ta n d p ro ce d u re s d e g re e vo l ta g e fo r is s u ch o f p o l l u ti o n is d e te rm i n e d at e va l u a ti o n s a re d e s cri b e d b e l o w ( s e e C l a u s e s B a n d B ) D i re cti o n s fo r ch e cki n g th e l a b o to ry e q u i p m e n t fo r a rti fi ci a l p o l l u ti o n te s ts , wh e n re q u e s te d , a re g i ve n i n An n e x E B.2 D e t e rm i n a t i o n o f t h e m a x i m u m wi t h s t a n d d e g re e o f p o l l u t i o n a t a g i ve n te s t vo l ta g e Th e i n s u l a to r s h a l l be s u b j e cte d to s e ve l te s ts at a g i ve n te s t vo l ta g e an d at d i ffe re n t d e g re e s o f p o l l u ti o n a m o n g th o s e l i s te d i n a n d Th e te s ts s h a l l b e p e rfo rm e d a cco rd i n g to th e te s t p ro ce d u re o f o r T h e te s ts ca n b e ca rri e d o u t i n a n y s e q u e n ce p ro vi d e d th a t: a) wh e n th e to ta l n u m b e r o f i n d i vi d u a l te s ts e n d i n g wi th fl a s h o ve r a t a n y d e g re e o f p o l l u ti o n re a ch e s two , no fu rth e r te s ts shal l be ca rri e d ou t at th e same or h igher d e g re e of p o l l u ti o n ; b) wh e n th e to ta l n u m b e r o f i n d i vi d u a l te s ts re s u l ti n g i n wi th s ta n d re a ch e s th re e , n o fu rth e r te s ts s h a l l b e ca rri e d o u t a t th e s a m e o r l o we r d e g re e o f p o l l u ti o n S h o u l d th e i n d i vi d u a l te s ts a t a n y d e g re e o f p o l l u ti o n l e a d to th re e te s ts re s u l ti n g i n wi th s ta n d , th e d e g re e o f p o l l u ti o n u s e d ca n b e d e cl a re d to b e th e m a xi m u m wi th s ta n d d e g re e o f p o l l u ti o n a t th e te s t vo l ta g e , p ro vi d e d th a t th e n e xt h i g h e r d e g re e o f p o l l u ti o n a cco rd i n g to o r l e a d s to two i n d i vi d u a l te s ts , e n d i n g wi th fl a s h o ve r I n th e ca s e o f s a l t fo g te s ts , th e p re co n d i ti o n i n g p ro ce s s ( s e e ) s h a l l b e p e rfo rm e d o n th e i n s u l a to r b e fo re th e d e te rm i n a ti o n o f th e m a xi m u m wi th s ta n d s a l i n i ty I f fo u r wi th s ta n d s o ccu r i n fo u r i n d i vi d u a l te s ts a t 2 kg /m ³ s a l i n i ty, th e m a xi m u m wi th s ta n d s a l i n i ty s h a l l b e a s s u m e d a s b e i n g e q u a l to o r g re a te r th a n 2 kg /m ³ I f o n e fl a s h o ve r a n d th re e wi th s ta n d s o ccu r in fo u r i n d i vi d u a l te s ts at 2 kg /m ³ s a l i n i ty, th i s s a l i n i ty sh al l be co n s i d e re d a s th e m a xi m u m wi th s ta n d s a l i n i ty B.3 D e t e rm i n a t i o n o f t h e m a x i m u m wi t h s t a n d vo l ta g e a t a g i ve n d e g re e o f p o l l u ti o n A s e ri e s of i n d i vi d u a l te s ts sh al l be ca rri e d ou t on i n s u l a to rs h a vi n g a g i ve n d e g re e of p o l l u ti o n E a ch te s t s h a l l b e ca rri e d o u t a t a n y o n e o f a s e ri e s o f vo l ta g e l e ve l s , e a ch o f wh i ch s h a l l b e a b o u t , ti m e s th e n e xt l o we r va l u e T h e te s t s h a l l b e p e rfo rm e d a cco rd i n g to th e te s t p ro ce d u re o f o r Th e te s ts ca n b e ca rri e d o u t i n a n y s e q u e n ce p ro vi d e d th a t: a) wh e n th e to ta l n u m ber of i n d i vi d u a l te s ts end ing wi th fl a s h o ve r at an y vo l ta g e re a ch e s two , n o fu rth e r te s ts s h a l l b e ca rri e d o u t a t th e s a m e o r h i g h e r vo l ta g e l e ve l ; l e ve l – 28 – b) wh e n th e to ta l n u mber of i n d i vi d u a l te s ts I E C TS : © I E C re s u l ti n g in wi th s ta n d at an y vo l ta g e l e ve l re a ch e s th re e , n o fu rth e r te s ts s h a l l b e ca rri e d o u t a t th e s a m e o r l o we r vo l ta g e l e ve l S h o u l d th e i n d i vi d u a l te s ts , a t a n y vo l ta g e l e ve l , re s u l t i n th re e wi th s ta n d s , th e vo l ta g e u s e d ca n b e d e cl a re d to b e th e m a xi m u m wi th s ta n d vo l ta g e a t th a t d e g re e o f p o l l u ti o n , p ro vi d e d th a t th e n e xt h i g h e r vo l ta g e l e ve l l e a d s to two i n d i vi d u a l te s ts e n d i n g wi th fl a s h o ve r In ca s e o f s a l t- fo g te s ts , th e p re co n d i ti o n i n g p ro ce s s ( s e e ) s h a l l b e p e rfo rm e d on th e i n s u l a to r b e fo re th e d e te rm i n a ti o n o f th e m a xi m u m wi th s ta n d vo l ta g e B.4 Determination of the 50 % withstand voltage at a given degree of pollution Th e i n s u l a to r s h a l l b e s u b j e cte d to a t l e a s t te n " u s e fu l " te s ts a t th e g i ve n d e g re e o f p o l l u ti o n Th e te s t s h a l l b e m a d e i n a cco rd a n ce wi th o r Th e a p p l i e d vo l ta g e l e ve l i n e a ch te s t s h a l l b e va ri e d a cco rd i n g to th e u p - a n d - d o wn m e th o d Th e vo l ta g e s te p s h a l l b e n o t m o re th a n % o f th e e xp e cte d % wi th s ta n d vo l ta g e Th e fi rs t " u s e fu l " te s t s h a l l b e s e l e cte d a s b e i n g th e fi rs t o n e th a t yi e l d s a re s u l t d i ffe re n t fro m th e p re ce d i n g te s t: o n l y th i s te s t a n d a t l e a s t n i n e fo l l o wi n g te s ts s h a l l b e ta ke n a s u s e fu l te s ts to b e co n s i d e re d to d e te rm i n e th e % wi th s ta n d vo l ta g e Th e ca l cu l a ti o n o f th e % wi th s ta n d vo l ta g e s h a l l b e m a d e u s i n g th e fo l l o wi n g fo rm u l a : U 50 % = ∑ (n i × N U) i wh e re : U n N i i i s a n a p p l i e d vo l ta g e l e ve l i s th e n u m b e r o f g ro u p s o f te s ts ca rri e d o u t a t th e s a m e a p p l i e d vo l ta g e l e ve l U i i s th e n u m b e r o f u s e fu l te s ts M o re d e ta i l s o n th e u p - a n d - d o wn m e th o d a n d p ro ce s s i n g o f th e re l e va n t re s u l ts a re fo u n d i n I E C 60 06 0-1 Al te rn a ti ve l y, th e m e th o d of m a xi m u m l i ke l i h o o d ca n be u sed i n fo rm a ti o n a b o u t th i s m e th o d wi l l b e fo u n d i n th e re l e va n t l i te tu re to o b ta i n U 50 % M o re I E C TS 5: © I E C 01 – 29 – An n e x C ( i n fo rm a ti ve ) Ad d i t i o n a l re c o m m e n d a t i o n s c o n c e rn i n g t h e s o l i d l a ye r m e t h o d p ro c e d u re s C.1 G e n e l Th e a d d i ti o n a l re co m m e n d a ti o n s g i ve n b e l o w g o m o re d e e p l y i n to th e p cti ce s o f th e s o l i d l a ye r m e th o d s Th e y p ro vi d e cri te ri a fo r a u xi l i a ry co n tro l s d u ri n g th e te s ts a n d h e l p u s e rs wh o a re n o t ye t s u ffi ci e n tl y e xp e rt i n th i s fi e l d fro m o b ta i n i n g i n a ccu te re s u l ts C.2 C o n ta m i n a ti o n Wh e n th e s p yi n g p c t i c e o r " fl o w- o n " p cti ce is u sed , th e o p e ti o n ca n be p e rfo rm e d on th e i n s u l a to r p l a ce d i n th e ch a m b e r i n i ts te s t p o s i ti o n Wh e n th e d i p p i n g p cti ce i s u s e d , th e i n s u l a to r sh al l be co n ta m i n a te d b e fo re i ts e re cti o n in th e te s t ch a m b e r If th e i n s u l a to r co n s i s ts o f s e ve l u n i ts i n s e ri e s , e a ch o f th e m s h a l l b e d i p p e d s e p a te l y a n d th e n b e ke p t wi th i ts a xi s ve rti ca l fo r th e d u ti o n o f d ri p p i n g o f th e co n ta m i n a n t a n d u n ti l th e l a ye r i s co m p l e te l y d ry I f, a fte r th e co n ta m i n a ti n g o p e ti o n , a b l o tch e d l a ye r i s o b s e rve d o n th e i n s u l a to r, i ts s u rfa ce s h a l l b e wa s h e d a n d cl e a n e d a g a i n a cco rd i n g to Th e n o n e o r m o re tri a l co n ta m i n a ti o n s a re p e rfo rm e d , e a ch fo l l o we d b y th e re l e va n t wa s h i n g , u n ti l a co n ti n u o u s l a ye r i s o b ta i n e d o n th e i n s u l a to r Th e te s ts m a y th e n b e s ta rte d E xp e ri e n ce h a s s h o wn th a t, i n g e n e l , i t s u ffi ce s to re p e a t th e o p e ti o n s e ve l ti m e s in o rd e r to h a ve th e i n s u l a to r s u rfa ce re a d y to be co n ta m i n a te d i n a s a ti s fa cto ry wa y, wi th o u t u s i n g a n y p re co n d i ti o n i n g p ro ce s s C.3 D ry i n g o f th e p o l l u ti o n l a ye r N a tu l d ryi n g o f th e p o l l u ti o n l a ye r o n th e i n s u l a to r m a y b e s u ffi ci e n t, p ro vi d e d th a t i t l a s ts l o n g e n o u g h ( h to h ) wh i l e th e re l a ti ve h u m i d i ty i s ke p t b e l o w % H u m i d i ty va l u e s l o we r th a n th i s l e ve l a l l o w s h o rte r d ryi n g ti m e s I f h o t a i r i s u s e d to a cce l e te th e d ryi n g o f th e l a ye r, th e m e th o d fo r p ro d u ci n g h o t a i r s h a l l n o t re s u l t i n th e d e p o s i ti o n o f m a te ri a l wh i ch a ffe cts e i th e r th e we tti n g o f th e i n s u l a to r s u rfa ce o r th e d e g re e o f p o l l u ti o n F i n a l l y th e s p e e d o f th e h o t a i r fl o w s h o u l d b e co n tro l l e d , i n o rd e r to p re ve n t th e d i s tu rb a n ce o f a n y co n te n t o f th e p o l l u ti o n l a ye r o n th e i n s u l a to r C.4 C h e c ki n g t h e we t t i n g a c ti o n o f t h e fo g Th e te s t i n s u l a to r, co n ta m i n a te d wi th th e s a m e s u s p e n s i o n a s th a t wh i ch wi l l b e u s e d fo r th e a ctu a l te s t, s h a l l b e p l a ce d i n th e l o ca ti o n wh e re i t wi l l b e te s te d I n s te a d o f th e te s t i n s u l a to r, a d u m m y i n s u l a to r, s i m i l a rl y p o l l u te d , p re fe b l y o f a s i m i l a r typ e ca n b e u s e d I n th i s ca s e th e d u m m y i n s u l a to r s h a l l b e i n s ta l l e d a s cl o s e a s p o s s i b l e to th e p o s i ti o n o f th e i n s u l a to r to b e te s te d , a n d a t th e s a m e a ve g e h e i g h t a b o ve th e fl o o r Wh i l e th e fo g g e n e to rs a re wo rki n g a s i n th e a ctu a l te s t, th e l a ye r co n d u cta n ce o f th e we t l a ye r o f th e te s t i n s u l a to r s h a l l b e p e ri o d i ca l l y m e a s u re d a cco rd i n g to th e fo l l o wi n g p ro ce d u re E a ch m e a s u re m e n t o f th e l a ye r co n d u cta n ce co n s i s ts o f a p p l yi n g to th e i n s u l a to r a vo l ta g e ( to 0 H z) n o t l o we r th a n 0 V p e r m e tre o f o ve l l cre e p a g e d i s ta n ce a n d m e a s u ri n g th e cu rre n t T h e vo l ta g e m u s t b e a p p l i e d fo r s u ffi ci e n t ti m e to d e te rm i n e th e va l u e s o f vo l ta g e – 30 – an d cu rre n t a n d s h o rt e n o u g h ti m e to a vo i d I E C TS : © I E C s e ri o u s e rro r d u e to h e a ti n g o r d ryi n g o f th e p o l l u ti o n l a ye r N o d i s ch a rg e a cti vi ty s h a l l o ccu r Th e i n cre a s e o f th e l a ye r co n d u cta n ce wi th ti m e s h a l l b e m o n i to re d Th e ri s e ti m e ≤ T ≤ 70 c T c sh al l be m i n ( s e e F i g u re C ) I f i t i s n o t, re p e a te d h u m i d i fi ca ti o n wi th d i ffe re n t s te a m i n p u t te s s h a l l b e ca rri e d o u t u n ti l T i s wi th i n th e s p e ci fi e d l i m i ts Th e s te a m i n p u t te s o c d e te rm i n e d s h a l l b e u s e d i n th e a ctu a l te s ts N O TE T h e l i m i ts fo r th e ri s e ti m e a re b a s e d o n e xp e ri e n c e fro m a c te s ts a n d h a v e b e e n c o n fi rm e d b y s o m e d c te s ts N O TE I t i s s u g g e s te d th a t a m o n i to r i n s u l a to r b e i n s ta l l e d a l s o i n th e a c t u a l t e s t c h a m b e r i n o rd e r to a c h i e v e i n fo rm a ti o n t o b e u s e fu l fo r a fu tu re re v i s i o n o f th e te s t p ro c e d u re s C.5 C h e c ki n g fo g u n i fo rm i t y fo r l a rg e o r c o m p l e x t e s t o b j e c t s I f th e te s t o b j e ct i s l a rg e o r co m p l e x ( e g m o re th a n m l o n g o r wi th s e ve l i n s u l a ti n g p a rts s u b m i tte d to vo l ta g e ) i t m a y b e n e ce s s a ry to ch e ck th a t th e fo g d e n s i ty ( a n d h e n ce th e we tti n g te ) i s u n i fo rm a t th e d i ffe re n t p a rts o f th e te s t o b j e ct U n e ve n we tti n g o f th e te s t o b j e ct, n o ta b l y i f th e l i ve e n d i s we tte d wh i l e th e re s t i s s ti l l re l a ti ve l y d ry ca n l e a d to i n co rre ct re s u l ts M e a s u re m e n ts a re m a d e n e a r th e te s t o b j e ct i ts e l f o r p l a ce d a t p o s i ti o n s co rre s p o n d i n g to th e p o s i ti o n o f th e te s t o b j e ct i f i t i s n o t p re s e n t I t i s l e ft u p to th e te s t l a b o to ry to d e ci d e o n s u i ta b l e m e a s u re m e n ts , typ i ca l e xa m p l e s a re : • C o n d u cta n ce m e a s u re m e n t on p o l l u te d dummy i n s u l a to rs ( m e a s u re d as d e s cri b e d in Clause C 4) T h e d u m m y i n s u l a to rs s h a l l b e p l a ce d a t p o s i ti o n s th a t fa l l wi th i n th e fo l l o wi n g g u i d e l i n e s : – Wi th i n to m l a te l d i s ta n ce fro m th e te s t o b j e ct – F o r te s t o b j e cts u p to m i n h e i g h t, o n e m e a s u re m e n t s i te i s s u ffi ci e n t a n d s h a l l b e p l a ce d a p p ro xi m a te l y a t th e m i d d l e o f th e te s t o b j e ct F o r te s t o b j e cts e xce e d i n g m i n h e i g h t th e n u m b e r o f m e a s u ri n g s i te s s h a l l b e i n cre a s e d to co ve r th e fu l l h e i g h t o f th e te s t o b j e ct It is re co m m e n d e d th a t th e m a xi m u m d i s ta n ce b e twe e n two a d j a ce n t m e a s u ri n g s i te s d o e s n o t e xce e d m • C o n d u cta n ce m e a s u re m e n t o n s e cti o n s o f th e p o l l u te d te s t o b j e ct i ts e l f i s p e rfo rm e d u s i n g s u i ta b l e e l e ctro d e s , e g co p p e r a d h e s i ve ta p e Th e co n d u cta n ce o f th e s e s e cti o n s is m e a s u re d a s d e s cri b e d i n C l a u s e C T h e l o ca ti o n o f th e e l e ctro d e s s h o u l d b e s u ch , to g u a n te e th e u n i fo rm we tti n g d i s tri b u ti o n a l o n g th e te s t o b j e ct In th e ca s e o f m u l ti p l e p a l l e l i n s u l a to r co n fi g u ti o n s , th e re i s n o n e e d fo r m e a s u re m e n t o n e a ch i n s u l a to r a rm I t i s re co m m e n d e d to ca rry o u t th e we tti n g te ch e ck a s d e s cri b e d i n C l a u s e C a fte r a n y a d j u s tm e n ts i n o rd e r to e n s u re th a t th e s te a m i n p u t te i s s ti l l co rre ct C.6 Fog i n p u t to th e te s t c h a m b e r Th e fo g s h a l l b e p ro d u ce d b y s te a m g e n e te d b y b o i l i n g wa te r i n o p e n ta n ks o r b y s te a m a d m i tte d at ch a m b e r sh al l l ow ve l o ci ty be th ro u g h a l l o we d on l y l a rg e a fte r d i a m e te r th e s te a m s p y n o zz l e s g e n e ti o n h as Th e fo g re a ch e d inpu t i ts to th e s te a d y te s t te Th e re fo re , wh e n th e s te a m i s p ro d u ce d i n ta n ks , th e s e s h a l l b e ke p t co ve re d u n ti l th e wa te r i n s i d e re a ch e s th e b o i l i n g p o i n t Th e i n s u l a to r sh al l be p o s i ti o n e d so th a t th e vi s i b l e fo g s u rro u n d s it as u n i fo rm l y as possi bl e T h e te m p e tu re ri s e i n th e te s t c h a m b e r, m e a s u re d a t th e h e i g h t o f t h e te s t o b j e c t, s h a l l n o t e xc e e d K b y th e e n d o f th e t e s t I E C TS 5: © I E C 01 C.7 – 31 – D u ti o n o f th e wi th s ta n d te s t P re s e n t kn o wl e d g e i n d i ca te s th a t th e fl a s h o ve r ri s k b e co m e s n e g l i g i b l e wh e n th e te s t o b j e ct wi th s ta n d s th e te s t vo l ta g e fo r 0 m i n fro m fo g a p p l i ca ti o n H o we ve r, th e ri s k o f fl a s h o ve r ca n b e d i re ctl y e va l u a te d d u ri n g th e te s t b y m e a s u re m e n t o f l e a ka g e cu rre n t o n th e e n e rg i z e d Th i s l e a ka g e cu rre n t n o rm a l l y re a ch e s a p e a k a n d th e n te s t o b j e ct d e cre a s e s d u e to wa s h i n g o f th e l a ye r Th e ri s k o f fl a s h o ve r i s co n s i d e re d n e g l i g i b l e i f m i n h a ve p a s s e d fro m th e s ta rt o f d i s ch a rg e a cti vi ty, i n d i ca te d b y th e l e a ka g e cu rre n t m e a s u re m e n ts Wh e n fl a s h o ve r is j u d g ed i m p ro b a b l e by m e a s u re m e n t of th e l e a ka g e cu rre n t or o th e r te ch n i q u e s , th e te s t ca n b e s to p p e d a n d co n s i d e re d a s a wi th s ta n d C.8 E va l u a ti o n o f th e re fe re n c e s a l t d e p o s i t d e n s i ty ( SDD ) Th e p o l l u ti o n l a ye r s h a l l b e re m o ve d co m p l e te l y fro m th e a re a o f th e i n s u l a to r ch o s e n to b e s a m p l e d At l e a s t th re e co n s e cu ti ve wi p i n g s o f th a t a re a s h a l l b e p e rfo rm e d As a n i n d i ca ti o n , l to l o f d e - i o n i z e d wa te r p e r s q u a re m e tre o f th e s u rfa ce to b e s a m p l e d ca n b e u s e d fo r d i s s o l vi n g th e co l l e cte d d e p o s i t Th e e ffe cti ve n e s s o f th e re m o va l o p e ti o n ca n b e ch e cke d b y m a ki n g m e a s u re m e n ts o f th e re s i d u a l d e p o s i t I t i s s u g g e s te d to ve ri fy th a t th a t th e ti o b e twe e n s u rfa ce o r o n l o we r s u rfa ce o f s h e d s ) a n d th e SDD o n l o ca l m e a s u re m e n ts o f SDD Layer d u ctan ce (per u n i t of th e m axi m u m val u e) l i e s b e twe e n , a n d , ,0 0, 0, t t t Test ti m e, t (m i n ) IEC F i g u re C – D e te rm i n a ti o n o f l a ye r c o n d u c ta n c e a n d e va l u a ti o n o f i ts ri s e ti m e T c = (on u pper th e wh o l e s a m p l e d a re a o f th e i n s u l a to r t – t – 32 – I E C TS : © I E C Annex D ( i n fo rm a ti ve ) Information to check equipment for artificial pollution tests To fa ci l i ta te th e a d j u s tm e n t o f l a b o to ry e q u i p m e n t fo r a rti fi ci a l p o l l u ti o n te s ts , va l u e s fo r th e wi th s ta n d ch a cte ri s ti cs of a fe w re fe re n ce su spen si on i n s u l a to rs a re g i ve n in Tabl e D Th e s e va l u e s , wh i ch a re b a s e d fo r th e ti m e b e i n g o n re s u l ts fro m o n e l a b o to ry l o ca te d l e s s th a n 0 m a b o ve s e a l e ve l , we re o b ta i n e d a cco rd i n g to th e re co m m e n d a ti o n s g i ve n i n th e p re s e n t te ch n i ca l s p e ci fi ca ti o n N O TE Va l u e s to c o m p l e te Ta b l e D.1 wi l l be i n s e rte d a ft e r d i s cu s s i o n of a va i l a b l e re s u l t s fro m d i ffe re n t l a b o t o ri e s N O TE Th e re fe re n c e i n s u l a t o rs g i ve n in Ta b l e D a re n o t to be seen as re p re s e n t a ti v e o f th e i r re s p e c ti v e c l a s s e s T h e i r c h o i c e d o e s n o t i m p l y i n i ts e l f a n y j u d g e m e n t o f m e ri t o r a n y a s s u m p ti o n t h a t th e y m i g h t h a v e b e tte r p e rfo rm a n c e t h a n o th e r s i m i l a r typ e s i n te s ts o r i n o p e ti n g c o n d i ti o n s T h e c h o i c e o f th e s e i n s u l a to rs i s b a s e d o n th e re c o m m e n d a ti o n s fo r t h e c o m p a ti v e i n te r- l a b o t o ry t e s ts o f t h e C I G R E /I E E E WG L a b o to ri e s s ta rti n g a rti fi ci a l 0 m a b o ve s e a l e ve l , p o l l u ti o n o r wh i ch te s ts o r wh i ch a re l o ca te d a t a l ti tu d e s h i g h e r th a n d o n o t co m m o n l y u s e o n e o f th e a b o ve - m e n ti o n e d te s t m e th o d s , m a y e xp e ct i n th e re l e va n t re s u l ts s o m e va ri a ti o n fro m th e n g e s o f va l u e s g i ve n i n Ta b l e D IEC TS 61 245:201 © IEC 201 – 33 – Table D.1 – (Provisional) Withstand degree of pollution and values of 50 % withstand voltage ( U50 % ) for reference insulators in artificial pollution tests Single arrangement in vertical position Results were obtained with tests procedures as given in the present technical specification U50 % Maximu m with stand degree of pollu tion Insulator type and number of unit per string Specifi ed creepage di stan ce Applied voltage m m /kV kV kV uni t Salt fog method k g /m Solid l ayer method m g /cm Salt fog method Salini ty kg /m Creepage di stan ce mm U50 % kV Solid layer method a Creepage di stance SDD m g /cm mm U50 % kV 70 mm Φ320 mm 0,02 390 87 0,02 730 44 0,02 960 05 0,02 353 02 Antifog creepage distance: 570 mm Minimum: units Antifog creepage distance: 390 mm Minimum: units unit Creepage distance: 960 mm unit Creepage distance: 353 mm a These values are determined in only one laboratory The reproducibility of the results is not established The influence of the steam rate and of the absolute amount of steam depending on the size of testing chamber has still to be clarified – 34 – I E C TS : © I E C An n e x E ( i n fo rm a ti ve ) S u p p l e m e n ta ry i n fo rm a ti o n o n a rti fi ci a l p o l l u ti o n te s ts o n i n s u l a to rs fo r vo l ta g e s ys te m s E.1 In of ± 0 kV a n d a b o ve ( s o l i d l a ye r m e th o d p ro c e d u re B ) G e n e l th i s a n n e x, s u p p l e m e n ta ry i n fo rm a ti o n , e s p e ci a l l y on te s ti n g fa ci l i ti e s , we tti n g s ys te m , ch e ck o f we tti n g a cti o n a n d s te a m i n p u t te , i s g i ve n wi th s o l i d l a ye r m e th o d –p ro ce d u re B fo r a rti fi ci a l p o l l u ti o n te s ts o n i n s u l a to rs fo r vo l ta g e s ys te m s a b o ve E.2 ± 600 kV Te s t ch a m b e r Re co m m e n d e d d i s ta n ce s ( i n m e te rs ) o f th e l i ve p a rts o f te s t o b j e ct fro m a n y e a rth e d s tru ctu re s h a l l b e g re a te r th a n m a xi m u m p h a s e to e a rth te s t vo l ta g e ( i n kV) d i vi d e d b y 0 Th e s a m e d i s ta n ce s h a l l b e m a i n ta i n e d b e twe e n th e l i ve p a rt o f vo l ta g e s u p p l i e r b u s h i n g a n d a n y p a rt o f te s t o b j e ct E.3 F o g g e n e to r Th e fo g ca n b e g e n e te d i n d i ffe re n t wa ys , s u ch a s b o i l e r( s ) i n th e te s t ch a m b e r, h o ri z o n ta l a n d /o r ve rti ca l n o z z l e s fe d b y e xte rn a l s te a m g e n e to r, o r co m b i n a ti o n o f th e a b o ve Wh e n n o z z l e s a re u s e d th e y s h a l l n o t b e d i re ctl y p o i n te d a t th e te s t o b j e ct E.4 We tti n g a cti o n a n d u n i fo rm i ty o f fo g d e n s i ty C h e ck o f th e we tti n g a cti o n a n d fo g d i s tri b u ti o n u n i fo rm i ty a cco rd i n g to C l a u s e s C a n d C i s re co m m e n d e d a t l e a s t a t e a ch ch a n g e o f te s t co n fi g u ti o n F o r l a rg e te s t o b j e cts th e re m a y b e s i g n i fi ca n t s ca tte r i n th e te s t re s u l ts , p a rti cu l a rl y a t U H V te s t l e ve l s T o m i n i m i z e th i s s ca tte r p re ci s e co n tro l o f a l l te s t p a m e te rs i s n e ce s s a ry Te s t e xp e ri e n ce n e ce s s a ry to i n d i ca te s i n cre a s e th e th a t i n i ti a l in a ca s e s te a m of high i n p u t te te m p e tu re fo r e xa m p l e as up in to su m mer it may , kg /h /m a n d be to a d j u s t th e te d u ri n g th e te s t F o r e xa m p l e th e i n i ti a l te co u l d b e ke p t fo r to m i n u te s a n d th e n d e cre a s e d fo r th e re s t o f te s t d u ti o n E.5 Te s t o f ve ry l a rg e i n s u l a to rs Wh e n th e m a i n o b j e cti ve o f th e te s t i s to o b ta i n i n fo rm a ti o n a b o u t th e p o l l u ti o n p e rfo rm a n ce o f i n s u l a to rs e g fo r co m p a ri s o n of d i ffe re n t i n s u l a to r re l a ti ve l y s h o rt i n s u l a to r s e ts ( e g a rci n g d i s ta n ce ≥ typ e s /p ro fi l e (see ), th e te s t on , m – i f re p re s e n ta ti ve o f th e fu l l s e t i n te rm s o f d i a l g e o m e try a n d p ro fi l e ) m a y b e s u ffi ci e n t I E C TS 5: © I E C 01 – 35 – Annex F ( i n fo rm a ti ve ) Further investigation Th e fo l l o wi n g p ro b l e m s n e e d fu rth e r i n ve s ti g a ti o n : – e ffe cti ve n e s s o f p re co n d i ti o n i n g wi th d c vo l ta g e i n th e ca s e o f s a l t fo g p ro ce d u re ; – i n fl u e n ce o f n o n - s o l u b l e m a te ri a l s o n th e te s t re s u l ts i n th e ca s e o f s o l i d l a ye r p ro ce d u re ; – i n fl u e n ce o f s te a m te a n d a ctu a l d c e l e ctri c fi e l d o n we tti n g ch a cte ri s ti cs ; – a p p l i ca ti o n o f a tm o s p h e ri c co rre cti o n fa cto rs ; – s a l t fo g te s t m e th o d fo r vo l ta g e s g re a te r th a n ± 600 kV – 36 – I EC TS 61 245: 201 © I EC 201 B i b l i o g p h y I EC 60507, A rtificia l pollution tests on h igh -volta ge cera mic a nd glass insula tors to b e used on a c systems [1 ] O u td o o r i n s u l a ti o n P a rt : Th e DC in ca s e p o l l u te d C I G RE co n d i ti o n s : Te ch n i ca l Gu id el i n es B ro c h u re _ N o fo r s e l e c t i o n 51 and d i men sioni n g INTERNATIONAL ELECTROTECHNICAL COMMISSION 3, rue de Varembé PO Box 31 CH-1 21 Geneva 20 Switzerland Tel: + 41 22 91 02 1 Fax: + 41 22 91 03 00 info@iec.ch www.iec.ch