Composed by RASHID. GRATITUDE By Allah’ s grace, comprehensive notes on “T e chnical Paper A-1&2”for the cand idat es h o in te nd to appe ar in Pr omot io n !"amin at io n fr om #p pe r Technical staff to $%nior !ngineer, have een caref%lly ritten' (t as not a child’s play' (t as really an %phill tas) for me' Than)s Allah ho enaled me to present s%ch a comprehensive treatise' *any peoples contri%ted ideas, s% gges tion, an d advices in th is ma tt er and ( e"tend my cordial th an )s to *r' *%hammad Aslam ++-1 .aroal/, *r' *%hammad A)ar An0%m A!T , *r' (0aAhmad ++-1, *r'T%nveer ++-((, *r' T%ns eer ++-1 and especially famo%s poet, riter, critic *r' $an ashmiri A! ho too) )een interest andprovided relevant material3informations in the prod%ction of these notes' The aesthetic sense of *r' $an ashmiri enaled me to compose these notes' B%t fortheir help and g%idance, ( co%ld do nothing' +%ggestions and proposals forimprovement of thes e notes ill e gratef %lly and highly elcome d' (IFTIKHAR ALI S SO-1 0333-811!80 " 0!31#138#$ TECH%ICAL &A&ER A-1"SRNO. ASKED QUESTIONS ANSWERS 1. WAPDA max. Transmission system voltage !!"v #. $orm%la &or single '(ase 'o)er *i +os , -. $orm%la &or t(ree '(ase 'o)er - *i +os , /. K)0 os , x K* A . At )(at lo%2 +ons%mer gri2 station is ne+essary A3ove !!!") 4. ONAN stan2s &or Oil nat%ral Air nat%ral 5. In 1-#611 "* 7ri2 st at io n8 )( at is stan2 ar2 rati ng o& 'o)er trans&ormer 1!61- 9*A8 *6#49*A :. 9DI stan2s &or 9axim%m 2eman2 in2i+ator ;intensity< =. W(at is '%r'ose o& %sing oil in trans&ormer ooling > Ins%lation 1!. ?engt( o& @T 2istri3%tion Poles ;&t< 1=8-48 /8 # 11. P7 +onne+tor stan2s &orParallel 7roves
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*r'(0a Ahmad ++-1, *r'T%nveer ++-((, *r'T%nseer ++-1 and especially
famo%s poet, riter, critic *r' $an ashmiri A! ho too) )een interest and
provided relevant material3informations in the prod%ction of these notes' The
aesthetic sense of *r' $an ashmiri enaled me to compose these notes' B%t for
their help and g%idance, ( co%ld do nothing' +%ggestions and proposals for
improvement of these notes ill e gratef%lly and highly elcomed'(IFTIKHAR ALI SSO-1 0333-811!80 " 0!31#138#$ TECH%ICAL &A&ER A-1"
SR NO.
ASKED QUESTIONS ANSWERS
1. WAPDA max. Transmission system voltage !!"v#. $orm%la &or single '(ase 'o)er *i +os ,-. $orm%la &or t(ree '(ase 'o)er - *i +os ,/. K)0 os , x K*A
. At )(at lo%2 +ons%mer gri2 station is ne+essary A3ove !!!")4. ONAN stan2s &or Oil nat%ral Air nat%ral5. In 1-#611 "* 7ri2 station8 )(at is stan2ar2 rating
1#. W(at is t(e &%se rating &or #!! K*A Trans&ormer 1"1-. W(at 'arts o& trans&ormer are ne+essary to 3e
eart(e2Bo2y C ne%tral
1/. W(at is stan2ar2 eart( resistan+e o& 1-#611 "v7ri2 station.
# o(m 6 Belo) !. o(m
1. B stan2s &or ir+%lar Brea"er14. W(at is meant 3y sag
;S0W?#6:T<
Pro'er +on2%+toring ;Sag0 ?o+ x 1!
x -61-!!< t(e tension o& +on2%+tor3et)een t)o 'oles is "no)n as Sag.
15. *T stan2s &or a'a+itive voltage trans&ormer.1:. a'a+ity o& 3attery is in2i+ator 3y A@1=. Is @*D transmission line is installe2 in Pa"istan No.#!. 7IS stan2s &or 7as Ins%late2 S%3 station ;s)it+(
gear<.#1. W(at is &%se rating &or Distri3%tion trans&ormer -"8 "8 1!"81"8 #!" ##. W(at is t(e Stan2ar2 Per+entage Im'e2an+e o&
Distri3%tion OR Po)er Trans&ormers
- to /
#-. @R &%se stan2s &or @ig( R%'t%ring a'a+ity.#/. ONA$ stan2s &or Oil Nat%ral Air &or+e#. O$A$ stan2s &or Oil &or+e Air &or+e#4. ONAN stan2s &or Oil nat%ral Air nat%ral#5. ONA$ stan2s &or Oil nat%ral Air &or+e#:. A stan2s &or Alternative +%rrent#=. D stan2s &or Dire+t +%rrent-!. 99 stan2s &or 9ill +ir+%lar mill-1. @o) m%+( 'ortion o& Distri3%tion Pole is 3%rie2 in
1!-. One BTU0 !.1K A?1!/. Unit o& s'ee2 R.P.91!. Unit o& magneti+ &lex We3er1!4. Unit o& &or+e Ne)ton1!5. Unit o& +a'a+itan+e $ARAD1!:. Unit o& 'ress%re BAR 1!=. Unit o& &reH%en+y @ERTJ11!. Unit o& (eat energy A?ORIE111. Unit o& resistan+e. O(m.11#. Wor"0 Po)er x 2istan+e11-. Psi stan2s &or Press%re6sH.in+(11/. Im'e2an+e o& 2istri3%tion Trans&ormer is /11. Trans&ormer %se2 in )a'2a 2istri3%tion system are Ste' 2o)n114. a'a+itors are installe2 at t(e sen2ing en2 o& 11"v
&ee2er to im'rove 'o)er &a+tor.Tr%e
115. In a soli2Gstate meter 'ermanent magnet +ontrols
t(e meter s'ee2.
Tr%e
11:. W(at is t(e stan2ar2 eart( resistan+e o& 1-#611 "vgri2 station
mont(6max.loa2 x no. O& (rs1#1. $orm%la 9ont(ly 'lant &a+tor Units generate2 2%ring t(e
mont(6'lant +a'a+ity x total (rs int(e mont(.
1##. ons%mers +onne+tion resistan+e 1! o(m1#-. BIO DATA ABOUT @T ONDUTORS1#/. Pant(er sie ;A< -!65 ;S< !.11: in+( %rrent +arrying +a'a+ity /-!G1!1#. Os'rey sie ;A< 1:61;S< !.154 in+( %rrent +arrying +a'a+ity /!G44!1#4. ?ynx sie ;A< -!65 ;S< !.11! in+( %rrent +arrying +a'a+ity -/!G/5!1#5. Dog sie ;A< 465;S< !.1:4in+( %rrent +arrying +a'a+ity #!G-!!1#:. Ra33it sie ;A< 461 ;S< !.1-# in+( %rrent +arrying +a'a+ity 1/G#!1#=. 7o'(er sie ;A< 461 ;S< !.!=- in+( %rrent +arrying +a'a+ity =G1/!1-!. BIO DATA ABOUT ?T ONDUTORS1-1. Was' 56!.15- in+( #-!G-1
1-#. ANT 56!.1## in+( 1-G#!!1--. 7nat 56 !.!:5 =!G1-!1-/. O?T stan2s &or On loa2 ta' +(anger1-. N?T stan2s &or No loa2 ta' +(anger.1-4. BIO DATA O$ $USES
1/!. #!!K*A 1K ORAN7E1/1. /!!K*A #!K LE??OW1/#. 4-!K*A /!K 7RAL1/-. ?T Distan+e 3et)een t)o s'an !!mm eH%al1//. 41 meter ?T s'an Sag allo)e2 1.#m1/. 1## to 1-/ meter @T s'an Sag allo)e2 #./ m1/4. $orm%la to +al+%late t(e +%rrent o& trans&ormer o&
3ot( si2es.I0K*A6-K* e.g. ;#!!"vaG11!!!6/!!<#!!x1!!61.5-#x11!!!
1/5. Stan2ar2 sie o& &ee2er lengt( ##to#"m1/:. Stan2ar2 lengt( o& ?T line 1"m1/=. 9aterial %se2 in lig(tening arrestor Sili+on +ar3i2e an2 lea2 'eroxi2e1!. One "ilo )att (o%r ;")(<0 -4!!a%les11. Bla2es o& gas t%r3ine are ma2e o& Alloy1#. A3sol%te ero tem'erat%re is G-!!
1-. Ba2 e&&e+t 3e+a%se o& +(emi+al a+tion is "no)n as orrosion.1/. @o) generator o%t '%t 'o)er is in+rease2 By im'roving P.$
1. W(y &ans are %se2 on TR. $or +ooling14. One KW@0 1 %nit15. In loa2 a+i2 3atteries %se2 as ele+trolyte. @#SO/1:. In 'o)er TR i& )in2ing t%rns are re2%+e2 t(en
)(at )o%l2 3e e&&e+t o& voltage on se+on2ary)in2ing
141. I& level o& +onservator tan" o& 1!! 9*A re2%+es a3it8 gas s(o%l2 3e a''lie2 on oil.
Nitrogen
14#. 1 in+( 0 #./ mm14-. 1 milli am' !.!!1am'14/. +os ,0 B+6a314. Po)er ;&or+e<0 Press%re x 16A144. is t(at tem'erat%re )(i+( (el's t(e t(ing to
3%rn )it( oxygen .Ignition tem'erat%re
145. .is t(e 3est +on2%+tor. o''er14:. are &ossil &%els. oal8 'etrole%m. Nat%ral gas.14=. In 3oiler o'eration8 ra2iation8 +on2%+tion8
+onve+tion sim%ltaneo%sly o++%r6(a''en.Tr%e
15!. E&&i+ien+y o& steam %nit is /151. I& tem'erat%re o& se+tion air o& +om'ressor
in+reases t(en.O%t '%t )ill 3e less.
15#. Ba33itt metal is 3asi+ally %se2 in Bearing15-. Tri''ing o++%rs on over s'ee2 o& t%r3o generator S%22en &all o& loa2.15/. I& magneti+ 'oles o& A motor are 2o%3le28 t(e ?ess.
s'ee2 at same &reH%en+y )ill 3e15. Po)er &a+tor o& ne) &a+tor.. Near to 1154. ?.T )in2ing o& TR on2%+tor in large sie155. @.T )in2ing o& TR on2%+tor in small sie15:. O(m la) *0IR 15=. Syn+(rono%s s'ee20 $6'1:!. Resistan+e O(m1:1. *ol. 9-1:#. Rea+tive 'o)er K*AR M?1:-. $reH%en+y 6s1:/. A++eleration 96se+#1:. *elo+ity 96s1:4. Press%re Psi1:5. In2%+tion @enry1::. E&&i+ien+y O%t '%t6in'%t x 1!!1:=. Area o& triangle0 Per'en2i+%lar x 3ase x (eig(t.
1=!. Units generate2 in ")( 0 Time x loa2 on %nit1=1. Watts0 *olt x +%rrent1=#. $reH%en+y 0;@ +6s< RP964! x P6#S1=-. SR o''er +on2%+torsteel rein&or+e21=/. @orse 'o)er is t(e %nit o& Po)er1=. T(e meggar is %se2 to meas%re .. o& ele+tri+
a''lian+esIns%lation
1=4. Am' meter is %se2 to meas%re %rrent1=5. *olt meter is %se2 to meas%re *oltage
1=:. T(e . Is t(e (eart o& t%r3ine 7overner1==. Ele+tri+ energy W(#!!. A+i2ity in TR oil ;3es<#!1. AA All al%min%m +on2%+tor#!#. ASR Al%min%m steel +on2%+tor rein&or+e2#!-. E9$ Ele+tromagneti+ &or+e#!/. ?.T ins%lator Srain C s'ool#!. @.T ins%lator Pin C 2is"#!4. Ty'e o& Ta' +(anger O&& loa2 .No loa2#!5. $orm%la o& voltage 2ro'0 KW@ x W.$ x 1!!61!!!#!:. Toleran+e o& *oltage >6G #!=. a'a+ity o& 3attery +ell # volt#1!. AW7 Ameri+an )ire ga%ge#11. E@* Extra (ig( voltage.#1#. U@* Ultra (ig( voltage#1-. D7 %rrent 2is" general#1/. ID9T Inverse 2e&inite minim%m time#1. Name o& 'ositive 'late o& 3attery P3o##14. Name o& negative 'late o& 3attery P3
#4/ The normal A4 s%pply Phase to earth/ voltage in Pa)istan is 255v $#4 (n a three phase 6-ire system %nalance c%rrent ill flo tho%gh ne%tral' T#44 4apacitance of circ%it plays important role in long transmission lines' T#45 +ilica 0ell is %sed to asor moist%re T#4: Transformers are easy to cool as compared to rotating machines' T#4= (n three-phase 7elta system phase voltage and line voltage are not e8%al' $#5! Battery is the lifeline of grid station' T#51 9ine c%rrent and phase c%rrent are e8%al in three phase star connections' T#5# (t is necessary to discharge capacitor hen isolated from the system for
maintenance'
T
#5- The nit of capacity of attery is A@#5/ +ingle Pole mo%nting s%-station is generally %sed for 155: transformer' T#5 ;igh press%re t%rine is some times called gas generator' $#54 <as t%rines %tility services are normally %sed for intermediate poer T
#5: 74 transmission lines have reactance' $#5= 74 transmission is economical for short distances' $#:! Three phase s%pplies are more economical than single phase in generation' T#:1 Three single phase transformers can e %sed instead of one three phase
transformer'
T
#:# The cond%ctivity of cadmi%m copper is more than Al%min%m' T#:- <alvanied steel is etter cond%ctor the Al%min%m' $#:/ Transformer cores are made %p of thin lamination to red%ce eddy c%rrent losses
only'
T
#: 7il%te ;ydro 4hloric Acid ;49/ is %sed in a storage atter as electrolyte $#:4 =resh !lectrolyte of the standard specific gravity is po%red in the storage attery,
if the level of electrolyte red%ces d%e to evaporation
$
#:5 >hile charging a strage atter thro%gh attery charger, positive terminal, of the
attery is connected ith the .egative of attery charger and .egative terminal
of atter to the positive terminal of attery charger'
T
#:= :oltage per t%rn in the secondary inding of a step %p transformer ill alays emore than the voltage per t%rn in the Primary inding' $
#=! >ater t%e oilers prod%ce steam at a press%re, higher than that fire t%e oilers' T#=1 (n any engine the press%re of air at the eginning of compression stro)e is more
than atmospheric press%re'
T
#=# >hat do e do to increase the o%tp%t voltage of a generator, )eeping its poer as
;ii< Over voltage;iii< Im'ro'er s'a+ing o& +on2%+tors.;iv< Over loa2e2 +ir+%its.
5' Po)er $a+tororre+tionG
im'roving.000000000
;i< By %sing stat%s +on2enser or in2ivi2%al +on2enser )it(motor.
;ii< By %sing large 3an" o& +a'a+itor in t(e system )it(a%tomati+ o'eration t(ro%g( 'o)er &a+tor relay.;iii< By %sing syn+(rono%s motor o'erating as +on2enser.;iv< By %sing syn+(rono%s in2%+tion motors.;v< Use o& stati+ +a'a+itor.;vi< Use o& '(ase mo2i&iers.;vii< Use o& '(ase a2van+er.
at one 'remise.;iii< ATBGBGTy'e s(o%l2 3e )el2e2.;iv< Rea2ings o& meter s(o%l2 3e got6 rea2 t)i+e time in one
mont(.;v< All 2ea2 sto''e2 meter s(o%l2 3e re'la+e2 imme2iately.
16' Rora $%seVG ?ine man %se rora &%se 2%e to t)o main reasons as %n2er;i< ?ineman %se rora &%se 2%e to t)o nonGavaila3ility o&
lin" ro2s in time )(en t(ey )ant to re'la+e 6 re'air ne)&%se to restore t(e s%''ly o& +ons%mer in emergen+y.;ii< D%e to 2e&e+tive &itting o& 'ro'er &%se.;iii< Rora &%ses are %se2 3y lineman &or easy o'erate. It (as
anot(er H%ality visi3ility.1' Di&&erent met(o2s
o& stealingele+tri+ity.
T(ere are so many met(o2s8 )(i+( are illegally %se2 &or ele+tri+itystealing.
;i< By tem'ering o& si2e seals 6 3o2y.;ii< By loo'ing;iii< By ma"ing )(ole in 3o2y.
;iv< By reversing o& meter rea2ing.;v< By +(anging 'olarity.;vi< By %n3alan+ing meter.;vii< By %n3alan+ing o& meter 2is".;viii< By sto''ing 2ea2 meter.;ix< By availing 2ire+t s%''ly.;x< I& t)o meters are installe2 in one 'remises t(e ne%tra
an2 '(ase are +(ange2 )it( ea+( ot(er.1C' A2vantages o&
trolley
trans&ormer.
;i< Use2 in emergen+y easily to restore t(e s%''lyGa&&e+te2area.
;ii< $or s(i&ting to one 'la+e to anot(er 'la+e to +o'e )it( anyemergen+y to restore t(e s%''ly o& t(e +ons%mer.1D' Preventive
maintenan+e o& trans&ormer.
;i< ?o%2 s(o%l2 3e eH%ally 3alan+e2 on every '(ase.;ii< B%s(ing o& trans&ormer s(o%l2 3e "e't neat an2 +lean.;iii< onne+tion o& 'rimary an2 se+on2ary si2e s(o%l2 3e
tig(tene2.;iv< Pro'er $%se s(o%l2 3e %se2 a++or2ing to t(e rating o
trans&ormer.;v< 9eggar test s(o%l2 3e +arrie2 o%t.;vi< Oil test o& trans&ormer oil s(o%l2 3e got +arrie2 o%t to "no)
t(e (ealt(y +on2ition.;vii< Ne%tral eart( s(o%l2 3e 'ro'er.;viii< Eart( assistan+e o& trans&ormer s(o%l2 3e +(e+"e2.;ix<
1E' 9et(o2 o& oiltesting.
To +arry o%t t(e oil testing8 sam'le o& trans&ormer oil is ta"en inoil testing set an2 t(e 2istan+e 3et)een t)o ele+tro2es is "e't#.mm t(em voltage is a''lie2. 7ra2%ally ratio o& voltage isin+rease2. W(en &las( is o3serve2 at a''lie2 voltage t(atH%antity is "no)n as 2iele+tri+ strengt( o& oil. Its val%e is %' to /!"v. T(is met(o2 is +arrie2 o%t times to +al+%late t(e a+t%al in
resistan+e.It is a 'ro'erty o& s%3stan+e )(i+( o''oses t(e &lo) o& ele+tri+ityt(ro%g( it. Its %nit is o(m an2 its sym3ol.
25' De&inition o& +on2%+tor.
T(ose s%3stan+es )(i+( (ave a small resistan+e 3%t t(ey rea2ilyallo) t(e &lo) o& ele+tri+ity t(ro%g( t(em +alle2 +on2%+tor.
21' De&inition o& Ins%lators
T(ose s%3stan+es )(i+( (ave a great resistan+e an2 t(ey 2o notallo) 'ra+ti+ally t(e &lo) o& ele+tri+ity t(ro%g( t(em.
22' O@9 It is t(e %nit o& resistan+e8 it is resistan+e in )(i+( a stea2y +%rrento& am'ere generate (eat o& one o%le6se+.
2' ?a)s o& resistan+e.
T(e resistan+e o& +on2%+tor varies 2ire+tly as its lengt( &orexam'le. One yar2 o& +o''er )ire (as a resistan+e !.!- o(m t(ant)o yar2s )ill (ave a resistan+e o& !.!4 o(m.
26' $orm%la &or+al+%lating t(e
resistan+e.
R x ?C R x 16A
2' S'e+i&i+Resistan+e
T(e S'e+i&i+ resistan+e o& a material is t(e resistan+e o& a 'ie+e o&%nit lengt( an2 %nit +ross se+tion.
2C' Disa2vantage o& lo)er 'o)er
&a+tor.
;i< +ost o& station an2 2istri3%tion eH%i'ment is more t(an agiven loa2 at lo)er 'o)er &a+tor.
;ii< ?o) 'o)er ma"es voltage reg%lation 'oor.;iii< ?o) 'o)er +reates tro%3le to maintain voltage )it( in
s'e+i&ie2 limits.;iv< $or t(e transmission o& a given 'o)er lo) 'o)er &a+tor
means more energy losses &or t(e same sie o& +on2%+tor.2D' a%ses o& 'oor
'o)er &a+tor.;i< A trans&ormer 2ra)s a magnetiing +%rrent )(i+( total t(e
+a%ses total +%rrent to lag )it( re&eren+e to E.9.$. atnormal loa2. T(is magnetiing +%rrent 2oes not a&&e+t'o)er &a+tor m%+( 3%t at lig(t loa28 t(e 'rimary +%rrent'o)er &a+tor lo).
;ii< Extensive %se o& in2%+tion motors res%lting in a lo) 'o)er&a+tor.
;iii< Over voltage;iv< Over loa2e2;v< Ar+ lam's.;vi< Also o'erate at lo)er 'o)er &a+tor.;vii< Po)er &a+tor is also m%+( lo)er o& one motor.
2E' W(y trans&ormer
rating in K*A.
As seen8 +o''er losses o& a trans&ormer 2e'en2s on +%rrent an2
iron loss on voltage8 (en+e total loss o& a trans&ormer 2e'en2s onvoltGam'ere an2 not on '(ase angle 3et)een voltage an2 +%rrentt(at is it is in2e'en2ent o& lo)er 'o)er &a+tor t(at is )(y rating o&trans&ormer is in K*A an2 not in KW.
2@' Po)ertrans&ormer.
T(e main '%r'ose o& a gri2 s%3Gstation is to ste' 2o)n t(e voltagean2 t(%s t(e main eH%i'ment installe2 at a gri2 s%3Gstation is aste' 2o)n trans&ormer8 +ommonly +alle2 as 'o)er trans&ormerT(e ot(er eH%i'ment installe2 at t(e gri2 s%3Gstation serve t(ereH%irement o& 'rote+tion &or t(e 'o)er trans&ormers &romvario%s ty'e o& ele+tri+al an2 me+(ani+al stresses8 over loa2ing8
over voltage8 over tem'erat%re an2 system &a%lts 3ot( onse+on2ary si2e an2 2ist%r3an+es6 &a%lts esta3lis(e2 in t(etrans&ormer 3o2y itsel&.
T(e ste' 2o)n 'o)er trans&ormer installe2 at any gri2station (ave +a'a+ity a++or2ing to t(e 'lanne2 loa2 reH%irement&rom t(at 'arti+%lar gri2 station8 )(i+( may very &rom 1! 9*A to#4! 9*A. It may vary at 3ot( levels8 i.e.8 it may 3e less t(an to
9*As or more t(an #4! 9W. T(e ste' 2o)n 'o)er trans&ormer8 &rom its 'arti+%larnomen+lat%re re2%+es t(e voltage &rom extra (ig(6(ig( voltage to11 K*8 )(i+( is 2istri3%tion system voltage. T(e 'o)er trans&ormers +ooling may 3e Air nat%ral$or+e2 Air +ooling or $or+e2 oil +ir+%lating system.
T(e 'rote+tion o& t(e 'o)er trans&ormer is 'rovi2e2 3yinstalling ot(er eH%i'ment i.e. +ir+%it 3rea"ers +%rrenttrans&ormer8 'otential trans&ormer8 isolators an2 lig(tingarrestors8 along)it( +ontrol an2 'rote+tion 'anels to 3e installe2
in2oor.5' ?ine an2 3%s 3arisolator.
T(e isolator is an eH%i'ment8 )(i+( is o'erate2 %n2er n%m3ersystem +on2ition8 )(i+( means t(at t(is eH%i'ment is o'erate2only %n2er n%m3er loa2 as it 2oes not (ave any ARQUEN@IN7 9EDIA. It (as male an2 &emale +onta+ts8 )(i+(2is+onne+t t(e 'arti+%lar +ir+%it in o'en air8 t(e o'eration may 3e+arrie2 t(ro%g( remote +ontrol system or lo+al o'eration systematta+(e2 )it( it. T(e 2i&&eren+e 3et)een line an2 B%s isolator ist(at t(e line isolator is 'rovi2e2 )it( 'ermanent eart(ing system)(i+( 'rovi2es 'ermanent eart( to t(e &ee2ing line. T(is'ermanent eart(ing system +an 3e 'rovi2e2 remote or lo+aman%al o'eration system8 t(e lo+al o'eration may 3e ele+tri+al or'%rely man%al.
Its im'ortant maintenan+e is +(e+"ing its +onta+t resistan+ein +lose2 'osition )(i+( s(o%l2 not in+rease t(an t(e val%ein&orme2 3y man%&a+t%rer. 9oreover8 its o'eration m%st 3esmoot( an2 +ontin%o%s i.e.8 t(e +onta+ts are to 3e +leare2 at are to3e +leare2 at reg%lar interval a++or2ing to t(e man%&a+t%rerss+(e2%le.
T(e +leaning o& s%''orting +ol%mns8 also ins%lating+ol%mns8 is also +arrie2 o%t as 'er s+(e2%le. are m%st 3e ta"en
in (eavy 'oll%tion areas &or +leaning or isolator +ol%mns an2male6&emale +onta+ts. T(e sili+on grease6in(i3itor +om'o%n2+on2%+ting grease to 3e 'rovi2e2 at t(e +onta+ts a&ter ea+(+leaning ;IN@IBITER O9POUND<
1' %rrentTrans&ormers
$rom t(e name it is %se2 to 'rovi2e re&eren+e +%rrent '%lse tomeas%ring6'rote+tive 2evi+es s%+( as +%rrent meas%ring metersan2 'rote+tive relays. 7enerally it 'rovi2es I am's. To am's.P%lse +orres'on2ing to &%ll loa2 +a'a+ity or t(e 'arti+%lar +%rrentrans&ormer8 normally it is man%&a+t%re2 as single %nit i.e.8 single
'(ase an2 installe2 as a got o& t(ree %nits &or t(ree '(ases. It is aseale2 %nit t(at reH%ires very less or almost no maintenan+e8 event(en t(e s+(e2%le2 testing is very essential 'arti+%larly +%rrentratio test8 s(ort +ir+%it test8 satis&a+tion test an2 CD$ test. T(esetests are +arrie2 to +(e+" t(e (ealt(iness o& t(e +%rrenttrans&ormer. In a22ition to a3ove8 t(e +leaning o& ins%lating+ol%mn an2 2iele+tri+ strengt( testing o& ins%lating6+ooling oil is
also +arrie2 o%t as 'er man%&a+t%rer instr%+tion. are m%st 3eta"en &or oil level to 3e +(e+"e2 &rom oil level ga%ge. In any +aset(e oil level s(o%l2 go 3elo) t(e re+ommen2e2 oil level o& t(eman%&a+t%rer. It normally (as t)o to t(ree se+on2ary )in2ingta's to get sa&ety at vario%s 'rimary +%rrent val%es s%+( as 1!G-!!G4!!66. T(e +%rrent trans&ormer is installe2 )it( ea+( +ir+%it3rea"er8 one %nit at ea+( '(ase8 )(i+( ma"e one set.
2' ?ig(tingArrestors.
T(is eH%i'ment is installe2 &or 'rote+tion o& 'o)er trans&ormeragainst lig(ting an2 system (ig( voltage s%rges. It is a +om'a+t%nits8 installe2 on (ig( voltage as )ell as lo) voltage si2e o& 'o)er
trans&ormer8 %st li"e +%rrent trans&ormer it is installe2 in single%nit at ea+( '(ase8 an2 t(ree %nits ma"e +om'lete set. $%rt(er8 itssingle %nit may +om'rise o& single8 t)o or even more t(an t)o+om'a+t %nits. T(e installation o& %nits m%st 3e a++or2ing to t(eman%&a+t%rer instr%+tions8 t(e %''er most8 lo)er most8 an2 ot(er%nits are mar"e2 &or installation. Wrong installation o& t(e %nitsmay lea2 to 2amage o& t(e 'arti+%lar %nit. T(e lig(ting arrestor+onsist o& series +a'a+itor en+lose2 in ins%lating +ol%mns (aving&ins to in+rease t(e lea"age +%rrent 'art(.T(e im'ortant +are regar2ing maintenan+es o& lig(ting arrestor8 is+leaning o& ins%lating +ol%mn an2 'rovi2ing 'er&e+t eart(ing att(e eart( 'oint mar"e2 at t(e lo)est most 'art o& a %nit.
Eart( testing an2 lea"age +%rrent testing m%st 3e +arrie2o%t as 'er s+(e2%le o& t(e man%&a+t%rer &or its 'ro'er o'erationan2 +(e+"ing (ealt(iness o& t(e lig(ting arrestors.
' PotentialTrans&ormer.
Potential trans&ormer 'rovi2es voltage '%lse +orres'on2ing to(ig( system voltage8 normally it is installe2 in single %nit at ea+('(ase8 an2 &or t(ree 'asses t(ree %nits are installe28 )(i+( ma"eone set. At most o& t(e gri2 stations8 only one set is installe28 &ormetering as )ell as 'rote+tion '%r'ose. T(e 'otentiatrans&ormers are normally installe2 )it( 3%t isolator at one si2eo& t(e gri2 station 3%t 3ar.
It is a seale2 %nit (aving 'rimary an2 se+on2ary )in2ingen+lose2 in an ins%lating +ol%mn +om'aratively same ma"e an2same 'rimary system voltage. Unli"e +%rrent trans&ormer it isinstalle2 in 'arallel to t(e system. T(e mineral oil is %se2 &or'rovi2ing +ooling an2 ins%lation. Normally it 'rovi2e 11! volt)it( re&eren+e to 'rimary system voltage an2 mar"e2 as ##! 1-#K*611! volts.
T(e im'ortant maintenan+e in+l%2e +leaning o& ins%lating3o2y against 'oll%tion an2 +(e+"ing oil level )(i+( s(o%l2 never
station )it( 'er&e+t 'ermanent eart( an2 eart(ing 'its. Ea+(eH%i'ment installe2 in t(e gri2 s%3station is +onne+te2 to t(iseart(ing mes( to 'rovi2e 'er&e+t eart( at t(e eart( mar"e2 'ointo& ea+( eH%i'ment.
$or 3etter sa&ety an in2e'en2ent 'ermanent 'er&e+t eart( is
to 3e 'rovi2e2 to t(e 'o)er trans&ormer an2 lig(tning arrestors8in a22ition to one eart( &rom t(e gri2 eart(Gmes(. In no +ase t(eval%e o& eart(Gmes( s(o%l2 in+rease more t(an !.# o(ms. Ro%tineeart( testing as 'er s+(e2%le is very im'ortant.
' S(iel2ing S(iel2ing against lig(ting at t(e gri2 s%3 station eH%i'ment is'rovi2e2 t(ro%g( s"y)ire installe2 at eart( mast an2 +onne+te2to ea+( gantry +ol%mn o& line as )ell as trans&ormer 3ay in s%+( a)ay to +over all t(e yar2 eH%i'ment against lig(ting. Provi2ing'er&e+t 'ermanent eart( to eart(ing mast an2 ea+( gantry+ol%mns is very essential. Eart( resistivity test as 'er s+(e2%le is
very im'ortant.C' ir+%it Brea"ers. @.T. +ir+%it 3rea"er installe2 in gri2 s%3station yar2 serves t(e
'%r'ose to isolate t(e &a%lty 'ortion o& t(e 'arti+%lar ele+tri+system. It +om'rises o& t(ree 'oles ea+( 'ole to isolate res'e+tive'(ase at a time. All t(e t(ree 'oles o'erates at t(e same 'arti+%lartime at t(e re+e'tion o& o'erating single to isolate t(e &a%lty'ortion or any reH%ire2 'ortion &or maintenan+e '%r'ose orot(er)ise. T(e ty'e o& @.T. or ?.T. +ir+%it 3rea"ers is 2enote2a++or2ing to t(e are H%en+(ing me2ia %se2 in t(e 'arti+%lar+ir+%it 3rea"er. T(e +ommon ty'e o& +ir+%it 3rea"ers installe2 at
Re+ti&ierT(e eH%i'ment is installe2 as in2oor8 i.e.8 in t(e +ontrol (o%se3%il2ing. It "ee's t(e D. 3attery in +(arge2 'osition8 )(i+(s%''ly D. +%rrent to vario%s eH%i'ment. T(e 3attery +(arger;11! volts D. or ##! volts< reH%ires re2%+e t(e li&e o& t(e 3attery.
@' Station 3attery T(e station 3atter is +onsi2ere2 as (eart o& t(e gri2 s%3Gstation2%e to its im'ortan+e as it s%''ly t(e signal to vario%s +ir+%it3rea"ers &or o'eration to isolate t(e &a%lty 'ortion o& t(e'arti+%lar ele+tri+ system or ot(er)ise i.e.8 it m%st 3e "e't in'ro'er +(arge2 'osition. Wa'2a (as 'res+ri3e2 2aily +(e+"ing o&
t(e 3attery &or its gravity ele+trolite level an2 'er +ell voltage &or2i&&erent +ells sele+te2 at Ran2%m an2 1!! +(e+"ing o& all t(e+ells on )ee"ly. Any 2e&e+tive +ell m%st 3e re'la+e2 on 'riority3asis.
T(e 'er +ell voltage &or Tri"le an2 3oost +(arging ismentione2 3y t(e man%&a+t%rer o& t(e 'arti+%lar 3attery an2 +arem%st 3e ta"en to maintain t(e 'er +ell voltage as mentione2 3y t(eman%&a+t%rers.TLPES O$ BATTERIESVGT)o ty'es o& 3atteries i.e.8 ;i< ?ea2 A+i2 3atteries8 an2 ;ii< Al"aline
3atteries are %se2 in 7ri2 stations. B%t ?ea2 A+i2 Batteries aremost +ommonly %se2 in 7ri2 Stations.?ea2 A+i2 BatteriesVG
B%t mostly lea2 Antimony Batteries are %se2 in 7ri2Stations 3e+a%se t(ese 3atteries are s%ita3le &or +y+ling i.e.8 &or&reH%ent +(arging62is+(arging an2 also t(ese 3atteries are lessex'ensive.PI?OT E??VG T(e 'oorest +ell in t(e 3attery is +alle2 PI?OTE??. It (as lo)est S.7.8 lo)est voltage an2 more se2iments at3ottom et+.
A2vantages o& (aving a 'ilot +ell6+ells in a 3attery areVG;i< It tells a3o%t t(e state o& +(arge an2 +on2ition o& )(ole
3atter.;ii< It minimies t(e la3o%r an2 (el's to maintain 3etter
+ontin%ity o& re+or2s.T(e ele+trolyte level o& 'ilot +ell m%st 3e maintaine2 on &%ll mar"
;9ore t(an one gat at a Time<;vi< $inal +(e+"ing an2 testing.;vii< ommissioning.
66' $ire &ig(ting $ire +an 3rea" o%t in any 'lant8 o&&i+e8 or (ome t(ere&oreeveryone m%st learn (o) to 'revent &ires an2 (o) to &ig(t t(em)(en t(ey 2o o++%r.
In or2er to 'revent &ires8 yo% m%st "no) (o) t(ey start. Inor2er to &ig(t &ires8 yo% m%st "no) (o) t(ey 3%rn8 (o) t(eys'rea28 an2 (o) t(ey '%t o%t. $ire 'revention reH%ires t(e same(o%se"ee'ing an2 sa&ety meas%res 2es+ri3e2 in ot(er mo2%les int(is %nit. T(e reasons &or some o& t(ese sa&ety 'ra+ti+es )ill3e+ome +learer to yo% as yo% st%2y t(is mo2%le.
Not all &ires are t(e same. Di&&erent "in2s o& &ires are &o%g(t
in 2i&&erent )ays an2 )it( 2i&&erent eH%i'ment. In t(is mo2%le8 )e2es+ri3e t(e vario%s "in2s o& &ireG&ig(ting eH%i'ment an2 (o) to%se t(em. T(is in&ormation )ill (el' yo% to avoi2 t(e +on2itionst(at +reate &ires. It )ill also 're'are yo% to &ig(t a &ire moree&&e+tively i& one 3rea"s o%t in t(e 'lant or in yo%r (ome.
AUSES O$ $IRET(o%san2s o& lives an2 millions )ort( o& 'ro'erty are 2estroye23y &ire every year. In in2%strial 'lants8 t(e +(ie& +a%ses o& &ires are&a%lty ele+tri+al eH%i'ment an2 t(e mis%se o& ele+tri+ity. Almost #'er+ent o& all &ires in in2%strial 'lants are ele+tri+al. arelesssmo"ing is t(e next8 +a%sing 1: 'er+ent o& in2%strial &ires8 a &ig%ret(at +o%l2 3e re2%+e2 greatly 3y more +are&%l %se o& smo"ingmaterials. $ri+tion +a%ses 1! 'er+ent8 an2 over(eate2 materials+a%se : 'er+ent.
Lo% +an see &rom t(ese &ig%res t(at most &ires in in2%strial'lants are +a%se2 3y slo''y )or" (a3its8 'oor maintenan+e8 or %st 'lain +arelessness. It s(o%l2 3e eH%ally +lear t(at &ollo)ingt(e sa&e )or" 'ra+ti+es 2es+ri3e2 in t(is %nit )ill 'revent most&ires. It +o%l2 also re2%+e in%ries an2 &atalities +a%se2 3y &ires.
$OUR ?ASSES O$ $IRE$ires are +lassi&ie2 a++or2ing to )(at is 3%rning. T(ese are &o%r
+lasses.;i< lass A &ires are o& or2inary +om3%sti3lesG 'a'er8 )oo2
+lot(8 r%33er8 an2 some 'lasti+s.;ii< lass B &ires are o& &lamma3le or +om3%sti3le liH%i2
gas8 grease8 an2 similar material.;iii< lass &ires involve energie2 ele+tri+al eH%i'ment.;iv< lass D &ires are o& +om3%sti3le materials.
A To Exting%is(ing reH%ires t(e (eatGa3sor3ing ;+ooling<7reen e&&e+ts o& )ater8 or t(e +oating e&&e+ts o& +ertain
B To exting%is(8 ex+l%2e oxy8 gen8 "ee' +om3%sti3leRe2 va'ors &rom 3eing release28 or interr%'t t(e +om3%stionrea+tion. ;$oam ty'e exting%is(ers<
$ires involving energie2 ele+tri+al eH%i'ment.
Bl%e Non+on2%+tive exting%is(ing agents are reH%ire2 to'rovi2e sa&ety to t(e o'erator. W(en ele+tri+al eH%i'ment is2eGenergie28 +lass A or B exting%is(ers may 3e %se2;+o#>Dry +(emi+al<
D $ires involving +ertain +om3%sti3le metals8Lello) in+l%2ing magnesi%m8 titani%m8 ir+oni%m8 so2i%man2 'otassi%m. Exting%is(ing reH%ires a (eatGa3sor3ingmaterial t(at 2oes not rea+t )it( 3%rning metal. ;+o#>Dry(emi+al<
W@AT TO DO IN ASE O$ $IRE C E9ER7ENLRE9E9BERFLo% are t(e +%sto2ian o& eH%i'ment C ma+(ine.Lo% (ave to sa&eg%ar2 it.Lo% (ave to 3e vigilant C )at+( &%ll.Lo% (ave to a+t as H%i+" as 'ossi3le in +ase o& &ire or emergen+ies.Kee'FD s%''ly so%n2 an2 (ealt(y an2 +(e+" on 3attery +(arger.$ire &ig(ting eH%i'ment t in o'erating +on2ition.omm%ni+ation system al)ays o'erating 3ri2ge (anging in&ront o& yo% t(e &ire emergen+y tele'(one no.
Sense C a+t imme2iate )(en t(ere is smo"e or alarm an2
ass%re (imsel& t(at a2eH%ate 're+a%tions to ins%re t(e sa&ety o&t(e )or" (as 3een ta"en. I& t(ere is any 2o%3t8 t(e 'o)er+ontroller s(all 3e +ons%lte2 3e&ore t(e )or" is starte2. W(en allis in or2er8 (e )ill iss%e t(e Permit to )or" to t(e a%t(orie2'erson in +(arge o& t(e )or". T(e a%t(orie2 'erson to )(om t(e Permit to )or" is iss%e2is res'onsi3le &orV
;a< S%'ervising all s)it+(ing8 gro%n2ing an2 ot(er lo+"ingne+essary to ass%re t(e sa&ety o& t(e )or" as 2ire+te2 3y t(e'o)er +ontroller.
;3< A&ter an a''arat%s (as 3een ma2e 2ea2 an2 eart(e28 a%tionNoti+es 2%lly &ille2 in an2 signe2 s(all 3e 'la+e2 on aleH%i'ment +ontrolling t(e a''arat%s %'on )(i+( men area3o%t to )or".
;+< W(en more t(an one 'arty o& men are )or"ing on ana''arat%s8 ea+( a%t(orie2 Person in +(arge o& ea+( 'artys(all (ave (is o)n +a%tion Noti+es on all +ontrolling
a''arat%s.;2< A''arat%s g%ar2e2 3y a%tion Noti+es s(all not 3e ma2e liveagain %ntil all t(e +a%tion noti+es (ave 3een remove2 in t(e'resen+e o& t(e a%t(orie2 'ersons in +(arge o& t(e 'arties)(o (ave 3een )or"ing on t(e a''arat%s.
;e< Danger Noti+es s(all 3e 'la+e2 3y ea+( a%t(orie2 'erson in+(arge o& a )or"ing 'arty on a''arat%s )(i+( may 3etem'orarily %ng%ar2e2 or %n2er re'air8 an2 is live or maya++i2entally or ot(er)ise 3e+ome energie2. S%+( noti+es s(alonly 3e remove2 3y t(e a%t(orie2 'erson )(o 'la+e2 t(em.
W(en )or" (as to 3e +arrie2 o%t at s(ort noti+e8 tele'(oni+instr%+tions may 3e ne+essary. In all s%+( +ases8 t(ese instr%+tionss(all 3e +on&irme2 imme2iately on t(e stan2ar2 $orms A6S an2B6S. All tele'(oni+ instr%+tions s(all &ollo) t(e same seH%en+ean2 'ro+e2%re an2 +om'rise t(e same in&ormation as reH%ire2 3yt(e &orms. All s%+( tele'(oni+ instr%+tions m%st 3e re+or2e2 in t(es%3station or2er Boo".
RE?EASIN7 A PER9IT TO WORK AND A SWIT@IN7INSTRUTION.
W(en )or" (as 3een +om'lete2 an2 t(e a''arat%s is rea2y to 3eret%rne2 to servi+e8 t(e (ol2er o& t(e Permit to )or" s(al
+om'lete t(e learan+e erti&i+ate 'art o& t(e Permit to )or" an2ass%re (imsel& t(at all men are +(e+"e2 +lear. @e )ill t(en re'ortt(is in&ormation to t(e Po)er +ontroller or t(e s%3G2ivisionao&&i+er +on+erne2 3y tele'(one. @e s(all state (is 'ermit to )or"an2 s)it+(ing instr%+tions serial n%m3er8 t(e a''arat%s on )(i+((e is +lear8 t(e n%m3er o& men in t(e )or"ing 'arties an2 t(egro%n2s an2 3lo+"ing to 3e remove2.
T(e 'o)er +ontroller o& s%3GDivisional o&&i+er +on+erne2s(all t(en 2ire+t t(at all gro%n2ing an2 ot(er 3lo+"ing 2evi+es 3eremove. W(en t(is is 2one8 (e s(all t(en ass%re (imsel& t(at all
+a%tion Noti+es are remove2 an2 t(e ne+essary s)it+(ing 2one toret%rn t(e a''arat%s to servi+e or reserve stat%s reH%ire2.
6C' Di&&erential Relay T(is relay is one t(at o'erate )(ere t(e ve+tor 2i&&eren+es o& t)oor more similar ele+tri+al H%antities ex+ee2s a 're2etermine2amo%nt. T(e )ay in )(i+( relay is +onne+te2 in a +ir+%it ma"es its2i&&erential. 9ost o& s%+( relays are o& +%rrent 2i&&erential ty'e.
Das(e2 line s(o)s 'ortion o& system element 'rote+te2 3y
2i&&erential relay. T(is system element may 3e lengt( o& +ir+%it8)in2ing o& generator a 'ortion o& a line. Over +%rrent relay is+onne+te2 a+ross t(e .T. se+on2ary +ir+%it.T(e 2i&&erential relay is one t(at &%n+tions 3y reason o& a2i&&eren+e 3et)een t)o H%antity o& t(e same nat%re s%+( as+%rrent8 voltage8 et+.
;iv< 9B@6D' Distan+e Relay T(e term im'e2an+e a''lies to resistan+e8 rea+tan+e or+om3ination o& 3ot( 'rin+i'les. In on im'e2an+e relay. T(e torH%e'ro2%+e2 3y a +%rrent in 3alan+e2 against t(e torH%e o& a voltageelement. T(e +%rrent element 'ro2%+es 'osition ;'i+"G%'< torH%e8)(ere as t(e voltage element 'ro2%+e2 negative ;Reset< torH%e@en+e im'e2an+e relay is a voltage restraine2 over +%rrent relay.Nomen+lat%reV. An im'e2an+e relay is in t(e average o& o'eratingat a given +onstant val%e o& to 18 )(i+( may 3e ex'resse2 as onim'e2an+e.
A''li+ationV. It is %se2 &or transmission line 'rote+tion.T(e &%n+tion o& 2istan+e relay is t(at t(ey o'erate 3y t(eim'e2an+e8 rea+tan+e8 an2 resistan+e o& t(e +ir+%it 3et)een relayan2 t(e &a%lt. T(ese relay are "no)n as 2istan+e relay.
It is a ty'e o& +%rrent 3alan+e relay. T(is ty'e o& relay (as oneover +%rrent relay element arrange2 to 'ro2%+e torH%e ino''osition to anot(er over +%rrent element8 3ot( elements a+tingon t(e same moving str%+t%re.
6@' B%+((los Relay B%+((los Relay is a gas a+t%ate2 relay %se2 &or 'rote+ting oiimmerse2 trans&ormers against all ty'es o& internal &a%lts an2ma"es %se o& t(e &a+t t(at &a%lts 2e+om'ose oil t(%s generating
gases. It is +onne+te2 3y means o& 'i'es 3et)een t(e to' o& t(etrans&ormer tan" an2 t(e +onservator an2 Is8 t(ere&ore8 %n2ernormal +on2itions o& o'eration8 &%ll o& oil.
It +onsists o& a +ast (o%sing +ontaining a (inge2 (ollo) &loatinsi2e o& )(i+( is a mer+%ry s)it+(8 t(e &loat 3eing lo+ate2 in t(e%''er 'art o& t(e (o%sing8 an2 a (inge2 &lat val%e to )(i+( is
atta+(e2 a similar mer+%ry s)it+(8 lo+ate2 2ire+tly in t(e 'at( o&t(e oil 3e 3et)een t(e tan" an2 t(e +onservator.W(en an in+i'ient &a%lt ;s%+( as isolation &a%lt 3et)een t(e
t%rns8 3rea"2o)n or +ore ins%lation8 +ore (eating8 3a2 s)it+(+onta+ts8 &a%lty oints< o++%rs in t(e trans&ormer 3%33le o& gas areevolve2 3y t(e (eat generate2 an2 rise %' to t(e tan" s%r&a+e an2t(en+e into t(e (o%sing o& t(e 2evi+e )(ere t(eir t(ro%g( 'assageis 'revente2 3y t(e &la' valve. T(e 3%33le 'ass to t(e to' o& t(e(o%sing8 +a%sing t(e oil level to &all8 )(ere %'on t(e (ollo) &loattilts an2 )(en t(e mer+%ry s)it+( +onta+ts are s(ortG+ir+%ite2 3y
t(e mer+%ry8 an2 alarm 2evi+e is o'erate2. I& (o)ever a serio%s&a%lt s%+( as internal s(ort +ir+%it 3et)een '(ases or t%rns8 eart(&a%lt '%n+t%re o& 3%s(ing ins%lators insi2e tan" o++%rs t(e vol%meo& gas generate2 is +onsi2era3le )(i+( in moving t(ro%g( t(erelay +a%ses t(e gas s%rge &la' valve to 3e 2e&le+te28 t(ere3y+losing t(e mer+%ry +onta+t s)it+( an2 energiing t(e tri' +oils o&t(e +ir+%it 3rea"ers.
It )ill 3e evi2ent t(at t(e relay )ill also res'on2 s(o%l2 t(eoil level &all 2%e to 3lo+"age &rom t(e tan".T(e +onne+ting 'i'e 3et)een t(e tan" an2 +onservator s(o%l2 3eas straig(t as 'ossi3le an2 s(o%l2 slo'e %')ar2s to)ar2s t(e+onservator at a small angle &rom t(e (oriontal.
5' Ta' +(anger T(ere are t)o ty'es o& ta' +(angers;i< On ?oa2 Ta' +(anger ;O?T<;ii< O&&G ?oa2 Ta' +(anger.
T(e Ist ty'e )or"s on loa2 'osition )(ile t(e se+on2 one )ill 3eo'erate2 a&ter '%tGo&& t(e loa2 o& 'o)er trans&ormer.$%n+tionsVGT(e ta3 +(anger is %se2 to ste' %' or ste' 2o)n t(e voltages as t(ereH%irement may 3e t(e )in2ing o& trans&ormer is se+tionalie2an2 ta's are ma2e t(ere are t)o s)it+(es name2.
;i< Divertor S)it+(;ii< Sele+tion S)it+(
In o&& loa2 ta' +(anger t(ere is no Divertor S)it+(.T(e 2ivertor s)it+( )or"s me+(ani+ally to o'erate t(e sele+ts)it+(8 )(ile t(e sele+t s)it+( sele+ts t(e ta' 'osition.T(e 'rin+i'le o& ta' +(anger is.*16v# 0 N16N#*# x 16N1W(en )e )ant to lo) t(e voltages )e '%s( lo)er s)it+( in t(is)ay t(e )in2ing t%rn +%tGo&& &rom t(e +ir+%it8 t(e voltage 3e+ome
lo)8 an2 )(en )e )ant to raise t(e voltage )e '%s( Raises)it+( in t(is )ay t(e )in2ing a22e2 in +ir+%its so t(e voltage3e+ome (ig( visa versa.T(e o'eration is +arrie2 o%t.#! to 4! m. se+.
1' Kin2s o& 3%s 3ar. ;i< $lexi3le;ii< Rigi2
2' Kin2 o& s+(eme%se2 in )a'2a
;i< One an2 (al& &or ##!6!! K* 7ri2 station.;ii< One an2 one &or 446 1-# K* 7ri2 station.
' Di&&eren+e3et)een T6?ine
an2 D6 ?ine
To 3ring t(e generate2 'o)er at 'o)er (o%ses ;@y2el T(ermal<to)ar2s loa2 +enters8 transmission system is 2evelo'e2Transmission system +onsists o& T6?ines as )ell as gri2 station.Transmission voltages %se2 in Pa"istan areVG
PRI9ARL TRANS9ISSIONV it +overs !!K* an2 ##!K*system.SEONDARL TRANS9ISSIONV It +overs 1-#K* an2 44K*system.ir+%itsV !! K* single @oriontal T %se2 in o%r system. ##!K* 1-#K* single an2 2o%3le verti+al T. Use2 ino%r system. 1-#K* C 44K* 2elta T %se2 in o%r system 44 K* (oriontal T %se2 in o%r system.DISTRIBUTIONVG
Almost &rom ea+( gri2 station 11K* &ee2ers give energy s%''ly toDistri3%tion system. T(is 11K* is &%rt(er ste' 2o)n to ##! voltan2 //! volt 3y %sing 2istri3%tion trans&ormer &or +ons%mer'%r'ose.