T Ime Setting; B Eari Ng And Contacts - GE IAV51A Instructions Manual

T IME SETTING

The time of operati on of the overvol tage rel ays i s determi ned pri mari l y by the setti ng of the time
di al , whi l e that for the under-and overvol tage re l ays i s de termi ned by the spread of the contacts as ex­
pl ai ned under VOLTAGE SETT I N G .
s upporti ng shel f ; movi ng the mag net i n toward the back of the rel ay decreases the ti me wh i l e movi ng i t out
i ncreases the ti me .
Fi g . 12 s hows t he t i me-vol tage c haracteri stics o f t he Type IAV51A and IAV52A rel ays wi th the d i a l
setti ng for obta i ni ng each characteri s ti c .
qui red ( to gi ve th e des i red characteri sti c ) by turni ng i t unti l th e number l i nes up wi th the notch i n th e
adjacent frame . The ti me i ndi cated by the curves i s the ti me requ i red to cl os e th e rel ay contacts when
th e vol tage i s suddenly i ncreased from a va l ue bel ow pi ckup to the va l ue on the curve .
Fi g . 13 shows the character i s ti cs of the Type IAV53A and IAV53B rel ay .
rel ay is automati cal l y determi ned by the setti ng of th e ra ti o of the vol tage to c l os e the r i g h t contacts
to the vol tage to c l ose the l eft contacts .
IAV53D re l ay . No curve i s gi ven for the Type IAV53C s i nce i ts time-vol tage characteri s ti cs a re expl ai ned
under the secti on head i ng CHARACTER I ST I CS .
The time-vol tage characteri s ti cs are pl otted i n percent thus ma k i ng them appl i cabl e for a l l tap
setti ngs .

B EARI NG AND CONTACTS

See MAI NTENANCE .
It i s recommended that suff i c i ent quanti ties of renewal parts be carri ed i n s tock to enabl e th e prompt
repl acement of any of those worn , broken or damaged .
mos t subject to wear i n ord i nary operati on and to damage due to pos s i b l e abnorma l cond i ti ons .
When orderi ng renewal parts , address the neares t Sal es Offi ce of the Genera l E l ectri c Company , s pec i fy
quanti ty requ i red , name of part wanted as shown by Figs . 15 and 16 , and g i ve compl ete namepl ate data ,
i ncl udi ng seri al number .
furni shed .
Further adj ustment i s obta i ned by mov i ng the permanent magnet al ong i ts
T o make time setti ngs , s e t the time d i a l to the n umber re­
Fi g . 14 shows the time-vol tage characteri s ti cs of the Type
RENEWAL PARTS
I f pos s i b l e g i ve the Genera l E l ectr i c Company ' s req ui s i ti on on wh i ch the rel ay was
GEH- 1 8 1 4
Pa rts bul l eti n number GEF-21 49 gi ves a l i s t of thos e
1 1
The time characteri s ti c of the