Serv I C I Ng And Adjustments; Target And Seal- In U N It; Voltage S Ett I Ng - GE IAV51A Instructions Manual

Voltage relays

Instructions manual (16 pages)

Instructions manual (12 pages)

Table of Contents

D I S K AN D BEARI NGS

The l ower j ewel may be tes ted for cracks by expl ori ng i ts surface wi th the poi n t of a fi ne needl e .

I f i t i s nece ssary to re pl ace the j ewel , the jewel shou l d be turned u p unti l the d i s k i s centered i n th e

ai r gap, after wh i ch i t shou l d be l ocked i n pos i ti on by the set screw provi ded for the purpose .

CONTACT CLEAN I NG

For cl eani ng fi ne si l ver contacts , a fl exi b l e burni sh i ng tool shoul d be used .

fl ex i b l e s tri p of metal wi th an etched roughened surfac e , resembl i ng i n effect a s uperfi ne fi l e .

pol i sh i ng acti on i s so del i cate th at no scra tch es are l ef t , yet corroded materi a l wi l l be removed rapi d l y

a n d thorough l y .

Th e fl exi bi l i ty o f the too l i nsures th e c l ean i ng o f the actual poi n ts of conta c t .

times an ordi nary fi l e cannot reach the actual poi nts of contact because of some obstructi on from s ome

other part of the rel ay .

F i ne si l ver contacts shoul d not be cl eaned wi th kni ves , fi l es or abras i ve paper or cl o th .

fi l e s may l eave scra tches wh i ch i ncrease a rc i ng and deteri oration of the contacts .

may l eave mi nute parti c l es of i n sul ati ng abras i ve materi a l i n the contacts and th us prevent cl os i ng .

The burn i s h i ng too l desc ri bed above can be obtai ned from the fac tory .

TARGET AND SEAL- IN U N IT

For tri p coi l s operati ng on cu rren ts rang i ng from

set the target and seal - i n tap pl ug i n the 0 . 2-am�ere tap .

For tri p coi l s operati ng on currents rang i ng from 0 . 2 up to 2 . 0 amperes at the mi n i mum con trol vol tage ,

set th e target and seal - i n tap pl ug i n the 0 . 2-ampere tap .

For tri p coi l s operati ng on currents rangi ng from 2 to 30 amperes a t the mi ni mum control vol tage ,

pl ace the tap pl ug i n the 2 . 0 -ampere tap .

The tap pl ug i s the screw hol di ng the right- hand s tati onary contact of th e seal - i n e l ement .

cha nge the tap setti ng , fi rst remove the connecti ng pl ug .

contact and pl ace i t i n the desi red ta p .

l eft-hand conta c t .

Th i s procedure i s necessary to prevent t h e ri gh t-hand s tati o na ry contact from getti ng

out of adj ustmen t .

Screws shoul d n o t b e i n both taps a t the same time as pi ckup for d i rect current wi l l

be the h i gher ta p val ue and a - c pi ckup wi l l be i nc reased .

VOLTAGE SETT I N G

T h e vol tage at wh i ch the contacts operate may be changed b y chang i ng the posi ti on of the tap pl ug

in the tap b l ock at the top of re l ay for rel ays such as th e I AV5 1 A , IAV52A , IAV53A , IAV5 3B , and IAV53D

wh i ch have tapped coi l s .

to 1 40 vol ts on th e 1 99 vol t ra ti ngs , 1 1 0 to 280 vol ts on the 208 , 230 and 240 vol t rati ngs , and 220 to 560

vol ts on the 460 vol t rati ngs .

The p i ckup of the rel ay for any vol tage tap i s adj us ted by means of a spri ng-adj usti ng ri ng .

ri ng may be turned by i nserti ng a tvol in the notches around the edge ( s ee F i g . 1 5 . )

the operati ng vol tage of the rel ay may be brough t i nto agreement wi th the tap setti ng empl oyed i f , for

some reason , th i s adj u s tment has been d i s turbed .

the vari ous taps .

The rel ay i s adjus ted at the fa ctory to opera te from any time-d i al pos i ti on a t a

mi n i mum vol tage wi thi n fi ve percent of the tap setti ng for the rel ays wi th the tapped coi l s menti oned

above .

For those rel ays wi th unta pped coi l s , pi ckup occurs a t a vol tage wh i ch is ei ght percent of rated

vol tag e .

The rel ays reset at 80 percent of th e operati ng va l ue on al l the overvol tage re l ays .

vol tage for the overvol tage rel ays is the mi ni mum vol tage for a gi ven tap setti ng at wh i ch th e contacts

jus t make .

On the under- and overvol tage rel ays such as the I AV53A , IAV53B , IAV5 3C , and IAV53D , the operati ng

vol tage for a gi ven ta p se tti ng i s the mi n i mum vol tage at wh i ch the l e ft-hand contacts c l ose .

hand contacts wi l l then cl ose at a certa i n percentage of operati ng vol tage .

th i s percentage , the ri ght-h and movi ng contact may be rotated on the shaft after fi rst l oosen i ng the

cl amp i ng screws th at hol d i t i n pl ace .

vol tage to c l os e the right-hand contacts between 50 and 9 5 percent of the vol tage wh i ch c l oses the l eft-ha nd

contacts .

Changi ng the pos i ti on of the ri ght-hand contacts changes the vol tage a t wh i ch the l eft-ha nd

contacts cl ose .

Hence , s i mu l taneous adjustments for cl os i ng l eft and ri ght contacts mu s t be made to obta i n

a de s i red characteri s ti c .

MAI NTENANCE