USRE15025E - X x x lxtstoa - Google Patents

Description

1 T. F. JOHNS I -I. JR, METHOD OF TESTING AND LOCATING [)EFECJHL MULTIPLE PART PIN TYPE INSULATORS; A FL !C "-C- HLED AUG 26.1920.

Reissued JI'HL 11 1921. I 15 ,025.

/ INVENTOR I, I I

' Y ,4 J ODZZZIZSOIZ/EQEATZSOmvJ T W l T N ES S E S ATTORN EY BEST AVAILABLE COPY l? is E .in al E0. 1,3013%:413, zlelseil May 6, 1915, Serial .Eo

reissue filed August 536,

, on, cit. on of lglie ll s. g; at illllfllllll in :Fflancl i 'tete of: Georgia, have invented new and useful Method Testing and lilocating Defective llflultiple-l ait Pin-Type insulators, of wnieli the following is :i'speeifio21- lsioro,

This -"ljl'1'VBl1lJlUll has reference to the mei liocl of testing multiplsperl; pimtype insulators to detect defects and locate such "leoias if present, and the Objfifil? is to pro- 'Vldfi e melliod whereby the condition of the insulators may be readily ascertained and ale-feels, if present, located Witl10utintei' ruptioro of service. v

The invonuion is an improvement upon the method of locating faulty suspension insulators on live Wire transmission lines fog; which an application for Letteys Patent filed y me on March 16 1918 under o. 2223M. The method disclose-1i in sppl aiion has in do w .ili Elie lgfiSililg LilliliOiS each which of "aspen is made i nsuletecl from the iiegliboirl 'lhe suspension-type 01" insulator the uniis made up of porcelain and oils conneeled together in series,

- is readily accessible, and uh string of suspension 0 procedures are necessary,

cle ots are so mm:- seeoi'iCl prose-Flore. y L boih 05 these pit :po only e si! lo instrument ong bio of ups a, on by one mum is 113ZK lQCL llibuEl-llfllllOT] employing pin type iiiinsulators are nmile up of sea ail cons'lil uiing :1 unit, A pimi ype ulster (fi'llllPllSQiS lawn or more nested parts 11 which loggers nii' uei'neni: are lodged. it has l'meiifmiml imposeibl: to practise me method applied in smpension. .lzi for testing pinlypo insiiletois, he on: il biwzllilfi n ccssaiy devise the method oi this spe ilinitlon, which differs em ilml: of tlie 'm'eszii il application in Specification of Reisseefi Meters Eaten-l.

11in Whether filed ficto'bfi'i' "me. serial No. ween.

tllei if conditions imit, shoriems. the line oomluctoi' o1: iZllG insulator suppones 111;; pin and e feelingsfiiok engaging o went layer, or two feeling sticks e. "1g

neighboring cement layers; by means ii good conducting bridging impleme 1; known; as a. shorting stick the Sh-OI'lJ-Cii'Cll ling also being performed in chosen order.

In the ILlBlJhOil applied to tlie'suepensiontype insulators two steps are empli'iyecl eml these steps necessitate the use of but one implement by one man In the method ployecl with the pin-type insulators file two steps cannot be employed in the manner forth in the e'pplication fo reasons 'Lmiieeessary to explain here, The step of pie liminaiv 0i tentative testing, or feeling-out, as it is i-medi, occurs in bot-l1 XIlllllUdSg-E I in obtaining the lcvaslo semi,

through the eemeiit. -1' 1e second step, in the ezise of the pin type insulator is materially clifierent from the see-fled with suspension insulators in that ii; beeoi lo: necessary to employ implement known e shorting stick in conneoeion with the feeling stick, or two of the lo'llez' es lo obtain the clesii'ecl intensila g of 5 ml iii drewing'the are. The IHG JlIOEl of team the pin-type insulators on charged high .lSQ-DSiDl! transm on lines requires the con Ynt 113-3 of two 01 three testing; implements me am oqiial number of men to manipulate lalieiu'i.

The invention will be best understood from n, consideration of the ii ollo'wing" (leiailed description liken in connection "with the accompanying drawing forming port of this speeillesiiiom with the understrmtlihg, limvewiy ilwtilie invention is molt confined 430 an sti'ict' conformity with jlzl'ie shaming the drawing bull may be changed modified so long as such elm mes and FILM, 1,- llcetinns mark no mlil'eiiel i pgm'ture oin. the salient features of 'the invention e20 pressed in tlieappemlecl claims.

In the drawings- Figure l is s View a multiple-- 1partpin-type insulator carrying a conduca transmission line and tor forming part of the feelingindicating a preliminary step in out procedure. 1

'Fig. 2 is a View similar to Fig. 1 but indicating a subsequent step in the feeling-out procedure. I

Fig. 3 is a similar view showing a preliminary step in the shorting test.

Fig: 4, is a view similar to" Fig.3 but showing a subsequent step in the" shorting,

. the voltage. maybe considered as 60,000 although'it is common 1n power transmission lines to have the current up to or above 100,-

volts 0 Such a current subjects insula tion to very heavy strains and the insulators employed. frequently break down,'thereby not only being dangerous to life but wasteful of current onaccount of the charge of the line. being grounded, and also stopping service.

The insulator is made up of severalp'orcelain parts 3, 4, 5, 6, although a lesser or a greaternumber of parts may be employed, the arrangement, adapted for the support of the conductor-.2 carrying'a currentof, say, 60,000 volts, and the several parts of the insulator are shown as of the skirted type. The skirt 6, being the part most remote from the conductor},

is mounted on a pin 8 of either'metal 01* woodand the pinis suitably supported on apole or tower. The several parts'fl of the inwhich, for certain types of insulators,

sulator are connected. together by cement 9. In carrying out the method, certain tools are needed and comprise a feeling--stick A and a shorting stick B. The feeling stick A has an elongated handle 10 of insulating qualities for the current being transmitted, such a handle being ordinarilyabout eight feet long and an inch and a quarter, more or less, in diameter. From one end of the handle there projects a pointed metal rod 11 be straight, but for-other types must be mode or less bent. In the drawing, only the straight form of pointed rod 11 is indicated. Where the rod emerges from the handle 10 a ferrule 12 may bea plied.

Theshorting stick is similar to'the feel ing stick A in that it is provided with a v The conthousands. For convenience,

best shown in Fig. 5, being I BEST AVAILABLE COPY handle 13, say, about eight feet magi- 1 an inch and a quarter in diameter, andat one end there is attached a metal Iork 14 with two arms 15 and 16' respectively. .Both of these arms are of metal and pointed at the free ends, the shape of these arms depending upon the particular form of in'sulatorito be In carrying out the method withftl'ie in?" strumentalities described and underlthe as,

sumption that the insulators are of the type shown, the first step is that of "feeling-out,

the insulator which is done withthe'feeling stick A. If the feeling-out process demon-' strates that it is's'afeto do so, the shinting process follows to determinejthe exact location of the fault.) If an insulator is very defective then the feeling oneration'indr applied. at all. The feeling operation-is inaccurate so far as definitely locating 311E311; but it will indicate, if the insulator be very defective, that the shorting operation would be -dangerous. very acfilllitte in locating the de ects but .is prohibitively dangerous unless preceded by the feeling operation audits ap licatio'i' governed in accordance with the in icatioh's of the feeling operation, q

In order to carry out the feeling operation the point of the rod 11 of'the stick A is touched to the line conductor 2, as shown in Fig. 1, and then drawn slowly away from cates thatthe shorting operation cannotbe Such shorting o oration is the line conductor. This produces a distinct away' from the cementthe soundwill not 01- Y low the feeling stick nearly so far as it would from the line conductor, if the pofiolain 3 be perfect. If, however,- the porcelain part ironithe cement between the parts 3 and :4

to the sound drawn directly from thl r.,.line

more and more defective. It would seem,

3 has become'defective the sound drawn will increase, approaching'nearer and nearer therefore, that when the insulatoifpart 3 is totally defective the. sound from the line and the sound from the cement between parts 3 and 4 will become equal, Such natural conclusion is but seldom verified'bywhat "actually, happens in practice; The sounds approach near enough to equality, under almost any conditions, to raise the suspicion thatpart 3 is totally defective butit is only a very exceptional occurrence that, the

sounds becomeactually equa1.- 'The o em; I I

point to and ment between the insulator parts ,4 and 5-; If

.tion is then repeated by'touching the feelingi drawingfit away from the ceconductor as the insulator part3 has becomq lle.

- greater the difference the newer perfect the v the degree of defectivenees of the pert BEST AVAILABLE co part 4 is perfect thesound given 0% Icy the cement will be less than the sound efif by the cement hefiween parts 3 and The nearer to equality the sounds approach the mere defective will pert- 4: be. When part 4- is totally defective the sound from the cement oil-each side cf it will in all cases be equal.

The ope-ration is repeated for: each unit part of the insulator and the difierence (the porcelain pm) in the sounds given by the cement on side oi any em. indicetes between the cemenl; sections. Vfihcn the le-ee part of the insulator, represented. by the part 6 in the drawing, is reached, ehe feel. ing operation is inede on *Tehe cement on one side and the pin 8 on the other side. Every part of a. multiplepefl; pindaype insnlecox: reeds true to form during'the feeling precess, except the top part 3. That. is, the sounds given 01? by the cementon each side of en insulate? pert willhe equal when the part between the cement sections 'is totally fdefective or dead,- except the iep part is very often- (lead whole the sound. given off bythe line conductor on One side end the cement on the other side said part will not be equal.

-l Vhen theieeling process gives indiceticns lihat the insulator is veer) defective theme is no need of using; the shorting process. However, when the feeling; process indicates shat the insulator enticely good the shorting prolz'ess should he used because this process huce-tes parts 'wlidch are only eliglltly defective and alsoloceeespe'riis which are totally. defective.

Thesherting process is applied to an insulate? only. afte" the feeling process has been first applied end has clearly indicated that it would be entirely safe to use the shorting process.

These parts of the insulator which give incliceiiio'n under the feeling process of he ing defective should he the first ones to be put to l he shorting test. This desirabl for if one of the good parts: were subjected h; the! shcrbin test 51 the insulator might ll sh, 5' where by shorfihlg the defecfive puns Ihst the number good parts remain ing (lefi sely cste] shed as Well as the such defiective degree of defectlvenees ol an insulator of more then two mg sticks A. are required if that the shorting process is to he followed out in an orderly manner from {he conductor be the insulator pin, then the feeling point of a feeling stick is placed firmly a :iinst the cement between the parts 3 and e 211m; of the jnlr. of placed, the line l A v defective the sound of the spell; will be less there end then the feeling fed 11 is moved into and out of contact with the other arm or 50m 01 the stick. This ereduces e snappy spark. If the top part cf "the insulator be perfect the sennd of zhe than the nol'mel spark of e perfect" end as the hep purl; or skirt; heccnlee wavingthe' cement spark will he that cf the normal gced top .pert or since If, hewever, theme @011 01 the the l good. a snappy spark will be'produced, but:-

the sound "will be less than that 0f the spark proamced across part 3 when the letter 15 1 W (1 f: *t' l 1 *k gooc. no a e ec mop-(1L we see Will be less and 1f the part he whollyjde fective then no spa-re: ee Wlll. be hem'd, The same condin'ilons hold good; fer all the yew-dining insulator parts. l' hen the last part 5 is reached the shorting is done between :1 point 0n the cement l tween the pares and 6 and lbhe pin suppor'tmg the insulator ll ench pin he 01? met-ll. 1f the pin be of weed a: feeling; point is ed fur 'ole the insmmor lnembel' in and the shorting is done between lng pe'ln'h ache feeling point ageinel; the cement between the in select)? parts 5 and .6, In the case of weed en pins the hcttoz'n skirt acts. very much like the top skirt. i

The testing of the insulatcns may he c0nvenientl doneby e. crew consisting of' persons, and as defective insulate-rs are die covered they are marked clmsplcueusly for insfiance, with o. deuho'l? red paint. testing crews zu-e followed by the malice!- lmnce crews who all lnerlied insulators doth the teselng and repl eingx of the insuletcrs are done while aye alive and infect the testing reqnwes that the lines heelive. l

Finch defects as ex" .zis on the u se-ref the ore-elem as, e. lI'ITOkGH insuletees, are not indicated by the method cf invention and in do not need to eince such defects 'escer'teineble on llihoiveven the-defecteexcend win l'rod y' cf the insnleeoy, defects be cracks, llolthe TQUI/lOD e eh the-tests s salable ineeww r en rl. i.

- defective insulators as discovered, all, occurrence of punctured insulators. on the sys- "tem can beeliminated. Furthermore, the

' both in the-electrical transmission of power tion power.

and of industries depending for their operaupon the furnishing of the electrical What is claimed'is a 1'. The method of testing and defective parts of multiple-part pin-type in sulators' on live transmission lines, which consists in drawing arcs, by means of an im-f plement of good'conducting material, from the line conductor and'from the cement between the parts of the pin-type insulator, in chosen order, and then short-circuiting, by means of a, bridging implement of good conducting material placed between the line conductor and a single conducting implement engaging the first cement layer in the insulator from the line conductor, and then between two single conducting implements connecting adjacent cement layers to shortoircuit the intervening insulator units throu h the cement, in chosen order.

2. 'fihe method of testing and locating defective parts of multiple-part pin-type insulators on live transmission lines, which consists in'drawing arcs, in chosen order, from. the line conductor and from the ce 1 inent between the parts of the pin-type inlocatingdEST AVAILABLE COPY and breaking the short-circuits to produce sparks.

3. The method oftesting multiple-part of a single implement of good conducting-- material to ascertain whether or not it issafetodefinitely locate the defective parts of suchinsulator, and then establishing current paths of good conducting material from the cement layers between the several elements of. the insulator and short-circuiting and breaking said paths about the elements of the insulator in chosen order, whereby to definitely locate faulty'parts.

4. The method of-testing multiple-part pin-type insulators on' live transmission lines, which consists in first tentatively testing the several parts of the insulator by drawing arcs in succession from the line conductor and from the different cement layers joining the several parts of theinsulator in order, and then establishing about each insulating unit of the i-nsulatora' path of good conducting material, in chosen order, with the path engaging the cement between the neighboring insulator units, and

then breaking the path of good conducting material to produce a spark, whereby the reliminary arcs-determine whether or not 1t is safe to establish paths of good conducting material about the insulator units and the character of the spark caused by breaking the conductin path determines the insulating quality 0? the part of the insulator being tested.

that I claim the foregoing In testimony have hereto aflixed my sigma as my own- I ture.

ronusson mar seamen-3r.

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