Bushing Potential Device TVPE KA-l08

Transcription

1 GE Prts Super Center Bushing Potentil Device TVPE KA-l8 ITRODUCTIO Power systems need low voltge equivlent of the system line voltge for relying or mesuring purposes. The most common method to obtin this is to use potentil trnsformer. Potentil trnsformers re very ccurte, but re expensive, both for purchse nd instlltion. They tke considerble spce in sub sttion nd require mounting pltform severl feet bove ground. High voltge bushings re common in substtions s prt of power trnsformers nd circuit brekers. HV bushings form cpcitnce divider s nturl consequence of the construction. So there is voltge signl vilble which is proportionl to the system voltge t every bushing bove 115kV fitted with voltge tp.. The Potentil Device connects to the Voltge Tp (Cpcitnce Tp) on the HV bushing nd provides: 1) Another cpcitnce in prllel to the bushing C2 to reduce the voltge to preferred vlue (between 3 nd 7.5kVl, 2) A stepdown trnsformer to step this voltge down to 115/ volts, nd 3) An djustble inductive rectnce used to correct the output voltge phse ngle to beinline with the system voltge. Fig. 1 Type KA-18 potentil device with door open showing the djustment pnel. Ground switch hndle t top interlocks with pnel when switch is "OPE" These instructions do not purport to cover ll detils or vritions in equipment or to provide for every possible contingency to be met In connection with instlltion, opertion or mintennce. Should further informtion be desired or should prticulr problems rise which re not covered efficiently for the purchser's purposes, the mtter should be referred to the' Generl Electric Compny GEI-95192G Supersedes GEI-95192F ISTRUCTIOS

2 GEI-95l92G Bushing Potentil Device, Type KA-lO The potentil device (Figs. 1 nd 2) will deliver n economic signl for relys, synchroscopes, voltmeters, nd other instruments. Since the ccurcy of the device is limited, it is not recommended for metering for revenue pplictions. The potentil device is energized from the cpcitnce tp of condenser bushing, circuit breker or current trnsformer. The potentil device is designted Clss A in ccordnce with EMA SG When properly djusted to suit prticulr bushing, the device will furnish two independent potentils of 115 nd 66.4 volts ech. The voltges re in phse with, nd hve fixed rtio to the line-to-ground voltge of the bushing. Rtio nd phse ngle vry slightly with chnges in line voltge, burden nd frequency, but remin within the limits permitted by the Stndrd EMA SG Sections (Voltge Regultion), (Burden Regultion) nd (Adjustment). RECEIVIG, HADLIG AD STORIG Exmine the equipment s soon s it is received for ny dmge tht might hve been sustined in shipment. If injury or rough hndling is evident, file dmge clim with the Trnsporttion Compny immeditely nd notify the nerest Generl Electric Sles Office promptly. Crefully inspect ll porcelin prts for dmge. Check ll led connections to mke sure they re in plce nd tht terminl connections re tight. Operte the grounding switch to see tht it is in good working condition. Lifting lugs re provided on the sides of the housing for verticl lifting If the device nd ccessories cnnot be instlled soon fter their rrivl, store them in clen dry plce. After continued storge, inspect for moisture on ll internl prts. Be sure ll prts re thoroughly dry before instlling nd using the device. DESCRIPTIO The bushing potentil device contins highrectnce trnsformer, djusting equipment, n uxiliry cpcitor, ground switch, protective gp, nd seprtely powered spce heter. These prts re contined in wetherproof steel housing. The high-rectnce step-down trnsformer is contined in n oil-filled tnk hving 1-inch (25.4-mm) ir cushion bove the oil. The high-voltge bushing connects to the primry coil. Secondry leds re brought out through low-voltge feed-through nd connected to tps on the power tp switch (Volts Corse) mounted to the trnsformer cover. Fig. 3 shows typicl Connection Digrm. The djustment equipment consists essentilly of n djustment trnsformer, phse-ngle cpcitors, nd power-fctor cpcitors. Rotry nd toggle switches on the front of the pnel control them. The hinged pnel cn be opened to provide ccess to the interior of the housing for mking primry connections nd corse voltge djustment vi the power tp switch. Fig. 2 Interior view of potentil device with pnel swung open. Ground switch "CLOSED" t top rer 2

3 GEI-95l92G Bushing Potentil Device, Type KA-lOB ADJUSTMET TRASFORMER AUXILIARY CAPACITOR (C3') +----t--'---tl-groud SWITCH HEATER P.A. & P.F. CAPACITORS TAP COECTIOS FOR 115V OUTPUT EFFECTIVE PRIMARY VOLTS - E VOLTS MEDIUM VOLTS COARSE c::::====~ if,~~~~~~adjustmet PAEL TERMIAL BOARD HEATER (35W) TO LI (FOR 12VAC Ll-L2) TO L3 (FOR 24VAC LI-L3) Cl Polrity Mrk r--~-,, ,,- 35-~-e- L L2 HI 32-~~~~~~ C3 L1 VOLTS 31 C3' 44H VTI_T2 3-4C~----~~~J 1849 T2 44H941, C3' 32.5*VTI_T2 942 & T1 Y3 C3' is lst three digits of Model umber divided by 1 (in uf) C2 I----'----r.~ --'-+----i~=?----~ I!; - - U 43 PHASE AGLE CAPACITORS IOIiF 27 Y2 38 ~ '" 39 ~~ 4--~~~~~~~::~~~-r~ Ti2 44 VA (1l5V! 6Hz) up" YI X3 X2 XI uf' 115v 66.4v OUTPUT XI-X3 Yl- Y3 X2-X3 Y2- Y '----Jl~J::, T. T. T. T. T. T. T. T. POWER FACTOR CAPACITORS Fig. 3 Connection Digrm Fine nd medium tp switches (locted on the pnel) finish the selection of the over-ll rtio. Rted totl wtt output cn be distributed in ny combintion between the X nd Y windings. Toggle switches in the phse-ngle section re identified by cpcitnce vlues nd in the power-fctor section by cpcitive volt-mperes t 115 volts nd 6 hertz. In 5-hertz pplictions, these power-fctor vlues must be multiplied by 5/6. A clerly mrked terminl bord t the bottom of the housing serves to fcilitte customer connections. CAUTIO - Terminls Ll, L2 nd L3, s well s the heter remin energized even when the ground switch is "closed." The uxiliry cpcitor supplements the tp-to-ground cpcitnce of the bushing, s required for voltge rtio nd rectnce mtch. Devices for Generl Electric Type F or OF bushings operte without the cpcitor. Use the grounding switch to remove the high-voltge input. The operting hndle extends over the front of the pnel, so tht the pnel cnnot be opened before closing the ground switch. Pull the hndle forwrd to ltch it into position. CAUTIO - WHE WORKIG ISIDE THE HOUSIG, USE A STICK AD BRAID TO PERMAETLV GROUD THE HIGH-VOLTAGE SECTIO. The protective gp t the HI bushing protects the primry circuit from over-voltges greter thn twice norml (15kV). The proper spcing (S/S-inch or 16 mm) is set t the fctory. A spce heter is provided to keep the comprtment dry. It requires seprte power supply of 38 wtts, 12 or 24 volts. The "H" led of the heter must be connected to'l1 or L3 s shown on the Connection Digrm. 3

4 GEI-95192G Bushing Potentil Device, Type KA-IB COSTAT-BURDE CAPACITY The potentil device output cpcity is not limited to the rted burden wtts listed in EMA SG 4 Tble 3-4. When the ppliction permits, substntilly higher burdens cn be connected to the unit. In such cse, the unit will still conform to EMA Stndrd SG 4 for Clss A opertion, except the burden regultion my exceed 12 percent (EMA SG 4 Section ). This is of no consequence when burdens re constnt, or vry only slightly. The incresed output is termed "constntburden cpcity". The tbultion Fig. 5 shows tht the constnt-burden cpcity is function of line voltge nd the cpcitnces of the high-voltge bushing. For exmple: t 79.7 kv, the device output cn be rised from 35 wtts rted to 55 wtts for bushing cpcitnce C1 equl or greterthn 475pf. 18 GE Bushing Potentil Device O. CAT. 44H94 TYPE KA-IOS CJ 6 HERTZ CJ 5 HERTZ c:::::::j/,3 LIE TO GROUD KV BURDE c:::::::j WATTS I SECODARY VOLTAGE CJ 115/66.4 VOLTS CJ 11/63.5 VOLTS CLASS A BUSHIG CII I pf e21 I pf "Use with Type A normlly grounded bushing tps onl~' ns defined by IEEE B44J52P2 WEIGHT 35 Ibs CAUTIO! BEFORE ISTALLIG OR OPERATIG RFAD Ii'lSTRUCTIOGEI Fig. 4 Typicl nmeplte ISTALLATIO MADE I U.S.A. CAUTIO - THE HIGH-VOLTAGE BUSHIG MUST BE DE EERGIZED BEFORE COECTIG THE POTETIAL DEVICE. Instlltion dimensions re shown in Fig. 7. COSTAT BURDE CAPACITY MAXIMUM OUTPUT WATTS FOR FIXED BURDES EMA C1 MITO BUSHIG CAPITACES LIE-TO- TABLE 3-4 ACHIEVE... C1 pf GROUD RATED RATED 4 I 475 I 575 VOLTAGE WATTS WATTS... WATTS Fig. 5 Constnt-burden cpcity COECTIOS TO BUSHIG 1. Remove the plug from the tp chmber of the bushing. Sve the oil from the chmber for future use. Insure tht the tp chmber nd cble end re free of contmintion. 2. Prtilly disssemble the cble hrdwre to permit visul contct enggement between the cble nd the bushing tp. Avoid turning the contcts on ech other, to prevent chip formtion. Tighten securely the two O-ring sels. 3. Refill the chmber with the sved or new compound. Leve 1/4-inch (6 mm) ir cushion for expnsion if the compound temperture is 25C. If the compound is heted to 13 C, omit the ir cushion. The ltter method is preferble for inclined tp chmbers. 4. To bolt the cble to either wll of the cbinet. open the knockout nd instll the gsket, which is stored in the housing. -12 UF2A ote: The cble is ordered seprte from the potentil device.. See GEI-7987 for cble connection instructions. Bushing Voltge Tp configurtions vry between mnufcturers. GE Bushing Potentil Device Cbles t the bushing end conform to IEEE C Type A: ormlly Grounded (See Fig 6). With proper cble dpters (provided by others) the GE Potentil Device cn be operted with bushing with other tp configurtions. GE Potentil Devices require 3 to 7.5 kv t the input terminls; the bushing must be ble to operte with this voltge-to-ground t the Voltge Tp. 1. MI t.29 GASKET SURFACE /.31 MI.375 -D.75 Fig. 6 Bushing Voltge Tp leee C Type A: ormlly Grounded 4

5 GEI-95192G Bushing Potentil Device, Type KA-I8 r BO (CMO LIFT lucsj------, ('. emr) ~u~.b~~:~t=hw=s=~~)~~~===ff1 I r"2t" r==j=2j.9' 2 1 r--i. JO.JO '-----lh~, j-- J.7,O, I, I, J~------: f.jo 9.9 J." 1.1S Pnel Door Swing Rdius 2.5 K ),: Pint light gry to EPS 9.1 (AT LOST 4.72 mils) I. HIGH VOLTAGE GABL[ COECTIO ETRACE 6. LIFTIG WG HIGH VOLT CABLE COECTIO (KOCK OUT FOR 2. ICH I.P.S.) 7. COTROL PAEL MUST BE ORDmm SEPARATELY CABLE MAY BE ISTALL D O EITHER SIDE. 8. KOCK OUT FOR.75 ICH 1.P.s. I BASE BUSHIG VOLTAGE TAP COECTOR 2. MOUTIG BRACKET 9. TERMIAL BOARD IS I[E[ C57.1IWI (1991) TYP A 3. GROUD STUD ( X.75 LOG) 1. BREATHER I BASE OT WEIGHT: 35 LB 4. AMEPLATE 11. GROUD SWITCH L VER SHIP W IGHT: 4 LB 5. DOOR 12. DOOR LATCH Fig. 7 Outline of bushing potentil device 5. Connect the cble terminl to the HI stud t the left, or to the bus support insultor stud t the right. The led should cler ny grounded components by two inches (51-mml. Check the protective gp for 3/8-inch (16-mm) spcing. LOW-VOLTAGE COECTIOS 1. Use knockout conduit openings t the bottom of the device. 2. Connect seprte heter power to Ll, L2 or L3 s shown on the Connection Digrm. 3. Connect the housing ground stud to ground. 4. Connect the burden to the desired output windings by consulting the Connection Digrm. With regulr polyphse connections using three devices (one device connected to ech phse of the line), the secondry windings re connected in "WYE" to supply rted vlues of potentil, either phse-to-phse or phse-to-neutrl. orml rted vlues of 115 nd 66.4 volts re vilble in phse with the line-to-ground voltge of the system. Also, 115 nd 199 volts re vilble in phse with the line-to-line voltge of the system. With the bove polyphse connections, residul voltge cn be obtined for ground indiction nd directionl ground rely opertion by connecting the tertiry windings in broken delt. This will not interfere with the connections of the min secondry windings, but the broken-delt burden must be considered when determining the totl lod on the devices. PRICIPLE OF ADJUSTMET The potentil device is correctly djusted when () rted secondry voltge is obtined with rted circuit voltge on the high-voltge line. The phse ngle is correctly djusted when (b) the secondry voltge is in phse with the high-voltge lineto-ground potentil. To set djustment (), voltge tps re provided in the min trnsformer nd djustment trnsformer windings. Proper tp connections re selected from the voltge tble on the Connection Digrm ttched to the cbinet door (or Fig. 3). This tble reltes effective primry voltge (E2) nd tp connections to obtin rted burden voltge t the secondry terminls. Voltge (E2) represents the "in-phse" component, not the totl, of the device primry Voltge. E2 vries with the cpcitnce rtio of the condenser bushing nd with the burden. Adjustment (b) is ccomplished by cnceling the cpcitive rectnce of the bushing with n equl mount of inductive rectnce in the potentil device. This is clled tuning the device to the bushing. Hereby the burden is ssumed to hve unity power fctor. The inductnce of the device is controlled by vrible cpcitor (phse ngle cpcitor) tht is energized from the coupling coil of the min trnsformer. An increse in phse ngle cpcitnce will rise the inductive rectnce. To phse in leding burden voltge, increse the cpcitnce. To phse in lgging burden voltge, decrese the cpcitnce. 5

6 GEI-95l92G Bushing Potentil Device, Type KA-lO Best operting conditions re usully obtined when the totl burden connected to the potentil device hs unity power-fctor or is somewht leding. Lgging power-fctor burdens cuse the primry voltge of the min trnsformer to be incresed bove norml. A power-fctor cpcitor is provided to correct lgging burdens bck to unity power-fctor so tht the bove condition does not exist. ADJUSTMET PROCEDURE All switches nd top connections for mking rtio, phse ngle nd burden power-fctor djustments re locted on the pnel (except Volts Corse is on the cover of the stepdown trnsformerl. It is recommended tht the potentil device grounding switch be closed when mking or chnging tp connections nd djustments. The output terminls should not be short-circuited since the protective gp will rc over continuously nd subject the primry circuit to bnormlly high-voltge stresses. The following procedure my be employed for djusting the potentil device to operte given lod from given bushing. BURDE POWER-FACTOR ADJUSTMET ote-on-liner burden impednce must be voided since the chrcteristics of the device my be ffected. Iron core relys should be operted t less thn hlf the sturtion density, to insure liner impednce. Refer to the Connection Digrm nd connect the power-fctor cpcitor in prllel with the instrument burden. ote tht the cpcitors cn be connected to X1-X3, X2-X3, Y1-Y3, or Y2-Y3. When prt of the burden is connected "WYE" (phse to neutrl) nd prt "DELTA" (phse to phse), connect the power-fctor cpcitor so tht it is in prllel with the prt of the burden contining the mjor inductnce. For "DELTA" burdens, led "F" cn be joined to n outgoing conduit wire by using blnk section on the terminl bord. The burden power-fctor cn be corrected to unity by ny of three methods. The third method is more ccurte becuse it mtches the ctul cpcitnces of the power-fctor cpcitor to the ctul inductnce vlues of the burden. The first two methods rely only on nominl vlues. I. If suitble power source nd meters re vilble, the totl instrument lod cn be ccurtely mesured nd segregted into its wtt nd rective volt-mpere components by the following formuls: Rective Volt-Amperes lso nd VAX~ VA x %PF = 1 1 _ (%PFi (1)2 Wtts Rective Volt-Amperes If the rective volt-mpere component is inductive (lgging) s usul, select power-fctor cpcitors for n equivlent vlue of cpcitive volt-mperes plus seven cpcitive volt-mperes extr. In cses where the rective volt-mpere component of the burden is lredy cpcitive (leding), select powerfctor cpcitors s required, so tht the totl leding vlue will be seven volt-mperes. II. When it is imprcticl to mke ctul mesurements, s described bove, n pproximte djustment of the burden power-fctor cn be mde s follows: Obtin rted burden of instruments being used from ctlogs, hndbooks or dt sheets tht pply. These vlues re usully given in terms of volt-mperes nd power-fctor nd my be segregted into wtt nd rective volt-mpere components s shown bove. Add up the wtt nd rective volt-mpere components of ll instruments connected to the device nd pply power-fctor correction in the sme mnner s bove. III. Plce n mmeter with 1- or 2-mp scle between Xl (or X2) nd the burden. Remove the "F" led nd connect it to the burden side of the mmeter. Red the voltge cross X1-X3. ow djust the power-fctor cpcitors until the burden impednce (Volts/Amps) becomes mximum. Add bout 7 VA dditionl correction. It my be necessry to redjust slightly the rtio nd phse ngle of the device if the power-fctor cpcitor settings re chnged from those originlly determined. RATIO AD PHASE AGLE ADJUSTMET The device should be connected to its prticulr bushing nd burden, which ws corrected to slightly leding power fctor. This section ssumes tht reference voltge s stndrd of comprison for the potentil device voltge is vilble. If not, djustments my be mde s described under "Adjustment By Clcultion." Accurcy of djustment depends on the relibility of reference voltge being in-phse with, nd in known rtio to, the bushing line-to-ground potentil. Since rtio nd phse ngle djustments ffect ech other, mke both lterntely. 6

7 GEI-95192G Bushing Potentil Device, Type KA-I8 The reference voltge my be produced by: 1. Another potentil device. 2. Potentil trnsformer. 3. Low-voltge winding of step-up trnsformer. 4. etwork energized by (3). with components to simulte impednce voltge drops from the trnsformer low-voltge winding to loction of potentil device. The reference voltge my be compred to the potentil device voltge by use of: () High impednce voltmeters (Vcuum tube VM, Flux VM, etc.). (b) Phse-ngle meter. (c) Rtio nd phse-ngle test set. (d) Oscilloscope. A reference voltge source nd mens to compre the reference voltge with the potentil device output is combined in one set of equipment in the Reference Potentil Set of the Doble Engineering Compny. Selecting combintion of winding tps tht will equlize the output nd reference voltges mkes rtio djustments. The rotorry tp switch (on top of the stepdown trnsformer) serves s the corse voltge djustment from the step-down trnsformer. Mnipulting the "medium" nd "fine" tp switches!locted on the djustment pnel) cn further refine the rtio djustment. OTE-When chnging the corse tp djustment. close the ground switch nd open the pnel. ;.. <I: I- z TAP COECTIOS FOR 115 V OUTPUT RATIO EFFECTIVE PRIMARY VOLTS - E2 MEDIUM w z u:, i= <I: :: RATIO COARSE Fig. 8 Tble for selecting preliminry tp settings Preliminry positions of the "corse" nd "medium" switch re determined from the tbultion on the Connection Digrm (lso Fig 8). Clculte voltge E2 (refer to "Adjustment By Clcultion")' Enter tble t nerest E2 nd select the corresponding tp for "corse" nd "medium" rtios. Exmple: When E2 equls 25 volts, use rtio corse tp o. 24 nd rtio medium tp o. 32 s preliminry djustment. The phse ngle is djusted to equl tht of the reference by connecting phse-ngle meter between the potentil device output nd the reference voltge. Mnipultion of the phse-ngle cpcitnce control is described under "Principle of Adjustment." The switch positions will hve to be vried s lternte phse ngle nd rtio djustments re mde, however the corse tp position does not ordinrily require chnge. A high degree of ccurcy is obtined when rtio nd phse ngle test set is vilble to blnce the burden voltge ginst reference If phse-ngle meter is not vilble, voltmeter cn be used. See Fig. 9. Connect potentil device terminl X3 to the grounded side of the reference Voltge. Connect voltmeter (VM-2) between Xl nd the reference Voltge. As the phse ngle reduces to zero, this difference voltge becomes minimum. Voltmeters with progressively smller voltge rnges should be used in order to permit minimum reding of pproximtely 1- volt. POTETIAL DEVICE (Xl) (X3) ' ' REFERECE VOLTAGE Fig. 9 Adjustment connections using voltmeter VM-1 for rtio nd voltmeter VM-2 for phse-ngle. Oscilloscopes lso fcilitte ccurte clibrtions. If one voltge deflects the verticl sweep nd the other the horizontl sweep, the scope serves for phsing-in minly, lthough it cnnot distinguish between zero nd 18 degrees phse ngle. (Connections shown in Fig. 1). The bem will describe n ellipse. As the ellipse reduces to single line, both voltges ssume equl or opposite phse. The opposite phse possibility is eliminted by scertining tht the difference voltge between references nd burden voltge is zero. The correct rtio is obtined with the id of high impednce voltmeter cross the burden. POTETIAL DEVICE (Xl '-- -' (X3) OSCILLOCOPE VERT HORIZ REFERECE VOLTAGE Fig. 1 Adjustment connections using voltmeter for rtio nd the for oscilloscope phse-ngle The oscilloscope cn be connected to serve s rtio nd phse-ngle detector, thus eliminting seprte voltmeter. See Fig. 11. The burden voltge deflects the verticl sweep while the difference voltge (burden minus reference) is impressed on the horizontl sweep. As zero phse ngle is pproched, the initil ellipse will reduce to single inclined line. This indictes equl phse. The inclined line will ssume verticl direction, s the rtio tends to equl the reference rtio. 7

8 GEI-95l92G Bushing Potentil Device, Type KA-lOS In both cses, the finl single trce my show ripples which result from difference in hrmonics of the two compred voltges. POTETIAL DEVICE (Xl.l. " BURDE (X3) OSCILLOCOPE VERT 1 HORIZ... REFERECE VOLTAGE Fig. 11 Adjustment connections using the oscilloscope for rtio nd phse-ngle djustments Adjustment by Clcultion This method yields firly ccurte djustments, if the potentil device secondry voltge cnnot be compred esily with known vlue. Determine E2 from: E2 EIC1 where "*" K (C1+C2+C3) El = Line-to-Ground volts of bushing K=1+.lx WB WR WB - Burdens wtts WR - Rted wtts from Fig. 5 C1 C2 = Cpcitnce (pfl from conductor to cpcitnce tp. Obtin from bushing nmeplte. Cpcitnce (pfl from tp to ground. Obtin from bushing nmeplte. If Cz is given, C2 = Cz - C1 C3 = Auxiliry cpcitnce. For models with "G" or "A" in 7th plce, obtin C3 from lbel on cpcitor connected to min trnsformer primry. For models with "B" or "C" in 7th plce, the three digits following the "B" or "c" in model number divided by 1, is C3' in llf. See Fig. 3 Connection Digrm. C3 = C3' / H94 series C3' / H941, 2, 3 series For exmple, ssume model 44H94C12 C3' = 12/ 1 = 1211f C3 = 1211f / 1849 = 649 pf Enter the tble on the Connection Digrm (or Fig. 8) t vlue nerest to E2. Select corresponding positions of the "corse" nd "medium" rtio tps. II. Phse Angle Determine the cpcitive impednce of bushing nd uxiliry cpcitor from: 1 12 Xc = ) (C1 + C2+ C3) ohms Where ) = 377 for frequency of 6 hertz, nd Cl, C2, nd C3 s previously defined. The required potentil device inductive impednce is then XL= Xc ohms Since XL is djusted by vrying the phse-ngle cpcitnce, determine the mount of phse-ngle cpcitnce from one of the impednce scles shown in Fig. 12. Select the pplicble impednce nomogrph by referring to the ctlog number on the device nmeplte. Refinement of Settings The burden hs been corrected to slightly leding power fctor s described under "Burden Power Fctor Adjustment." Do not lter these settings. Plce high resistnce voltmeter cross the terminls to which the burden is connected. The potentil device ground switch should be closed when chnging rtio nd phse-ngle settings. A record of voltmeter redings, rtio nd phse-ngle settings kept during djustment will be of vlue in rriving t the finl settings. Proceed s follows: Chnge the phse-ngle switches by smll positive or negtive increments (.4 to 1. pf) to find resonnt pek in the output Voltge. Use smller steps (.1 pf) ner the pek. ow djust the rtio settings by smll steps (Volts Fine Tps) to rech the desired voltge level, such s 115v. For ech rtio step, serch gin for the resonnt pek with fine steps in the phse-ngle cpcitnce. The ctul cpcitnces will vry slightly from the switch mrkings. Also, the rtio controls will ffect phse ngle nd conversely the phse ngle ffects the rtio. The finl settings re likely to differ somewht from those determined by clcultion. 8

9 GEI-95l92G Bushing Potentil Device, Type KA-lOB Cpcitive Rectnce - kn L() t- o L() T""" ('I') ' " L() co Ctlog I I,, II, I, II,, I ',I 'I,I,I Series ' 1,1 I L() L() ' " co eo eo > T""" T""" T""" T""" T""" Ctlog I, I',I ' I I,, I,, I I, I ' I, II I, I,, I, Series L() L() L() L() t- t- eo eo > > T""" I,, I,,I I' 'I Ctlog, I,,I T""" ' I ' I, II Series Phse Angle Cpcitnce - IlF Fig. 12 Rectnce ohms vs. phse ngle cpcitnce Field Adjustment By omogrph The nomogrph (see APPEDIX) presents simplified method of finding the switch settings; thus replcing the clcultions given in the foregoing section. This is vluble not only in ctul field clibrtion, but lso when considering moving the device to nother bushing, or even to different circuit voltge. In pplying the grph, determine cpcitnces C1, C2, C3 s descried in section "Adjustment By Clcultion." HOW TO USE OMOGRAPHS: Select pproprite nonogrph by mtching the first 6 digits of the model number with the grph. Plot the sum C1 + C2 + C3 + cble cpcitnce on "Totl Cpcitnce" Scle, the required phse ngle cpcitnce is red from the "Phse Angle Cpcitnce" Scle. Rtio settings re found by drwing line from the bove-mentioned sum, through C1 on "C!" Scle to intersect the "Reference" line. Then from this point on the reference line through the "Iine-to-line voltge" Scle to the "Corse nd Medium Tps" Scle from which Volts Corse nd Volts Medium tp positions cn be determined. 4-5 EXAMPLE: For the exmple shown in APPEDIX A for 23kV system: C1 = 35pf, C2 = 795pf, 2ft cble = 98pf, nd for model 44H94C12, C3 = 649pf (see "Adjustment by Clcultion" to determine C3 from model number); thus Totl Cpcitnce is 935pf. From "Phse Angle Cpcitnce" Scle, phse ngle cpcitnce is determined to be 13 Ilf. Rtio tp positions become 27 nd 3. Refer bck to "Refinement of Setings" to finish clibrtion. REEWAL PARTS Plce orders for renewl prts with the nerest Generl Electric Sles Office. Specify the quntity required nd give the ctlog or prt numbers of the required prts. If these numbers re not obtinble, describe the prts in detil. Alwys give the seril number nd the complete nmeplte rting of the equipment. GtE Prts Super Center GEI-95192G Supersedes GEI-95192F 9

10 GEI-95192G Bushing Potentil Device, Type KA-IOB APPEDIX A RATIO & PHASE AGLE OMOGRAPH (44H94 SERIES) COARSE TAP MEDIUM TAP E2 (volts) ;;; (") r-. rt> (") M (") "'7 '" '<t ;;; (") M M (") (") '" (") " '" '7 " '" '7 (") ;;; '7 '7 '7 '7 M L{) (") (") " to ;;; (") '7 (") '" " '" r- " M M M '" (") (") <D co co co '" CD LI E-TO-li E VOLTAGE (kv) ;::: '" CD (") " '" REFERECE LI E Cl (pf) :5 I"- g < g L!) g...r g ("') g -V +H-++++I+j-f-iI-+I++-I--t1I+-H--+-+-H TOTAL CAPACITACE (Cl + C2 + C3) - pf PHASE AGLE CAPACITACE - uf, <D (") '" ;! ;::: OJ CD ~. c:i L{) r-. ~ <D '" " '" 1

11 GI m T VI»" -... "OJ:» ~~ 1. Oen +r m =im '" ~g GI»> ~~ < ~ Zz +" " "O~ 1 ", :g m c: mr n~ ~ en ~m - "....» :r. " "'z.=. ::l " (Q m 17 3." 31 1." 31 r+ /D 3 9 ::l 32 r e: /D < n 27 7.!D 5.-E I Ie: "C 6 /D r "» 33 I :; ClO 35 l> > 23 I-d ~ :::!... zo 14 ~ 22 J:OI/O 31 ~s:"'il ~ OJ: ~ 1.~ 3 3 I-d 21 T eng'll>... Lo 33 m::oen 35 :;o»m ~ 34 -"'Ill> ~ 35 mj: Z 2 13 ~ G'l r m 15.-t 31 t <r rz m 3 >-'i "' 55 31!!!t ;n "'Z m.:5m " m ill Z 34 n m r 35 Z 68 m I 22.5

12 ..