Constr Uction - GE IAV51A Instructions Manual

the other two ph ases a re g rou nded, the relay voltage i ncreases to rated volta g e a n d the
left-hand contacts close in a pp roxi mately 1 0 seconds.
The IAV53D relay is si m i lar to the Ty pe IAV538 relay except that it has a sh o rter time cu rve.
Time/voltage ch a racte ristics a re shown in F i g u re 1 4.
The Type IAV 5 3 K is si m i l a r to the Type IAV53A, IAV5 3 L to IAV538, IAV53M to IAV53C a n d
IAV53N t o IAV53D.
While the IAV53A,B ,C,
d o u b l e-end case, with co ntacts con nected between t h e u p p e r and l owe r b l ocks a n d
t h e b reaker if the co n necti ng p l u gs a re removed and subseq u e ntly rei n serted with the
relay in the reset positi on, i .e . , ci rcu it-ope n i n g contacts cl osed . I n se rtion of e ith er p l u g
ca uses t h e rel ay to p i ck u p ; both plugs must be i n pl ace befo re t h e contact ci rcu its a re
com p l eted . See i nterna l con nections F i g u res 1 - 8 for coi l and contact ci rcu its, a nd F i g u res
1 0 and 1 1 for exte rnal co n nectio ns.
These relays a re of the i n d u ction-d i sk co nstructi o n . The d isk is actu ated by a potential
operat i n g coi l on a l a m i nated U-mag net. The d isk sh aft ca rries the movi ng contact, wh i ch
com pletes the tri p or a l a rm circu it when it touches the stati o n a ry contact or contacts. The
d isk shaft is restra i n ed by a spi ral spri ng to g ive the proper contact-cl osi ng voltage, a n d its
motion is reta rd ed by permanent magnets acti ng on the d isk to g ive the correct ti me delay.
There is a sea l-i n u n it mou nted to the left of the shaft of all but the IAV5 38, D, L and M
models , as shown i n Fig u re 1 5 . This u n it has its coi l i n series a nd its contacts i n para l l el with
the m a i n co ntacts, such that when the ma i n contacts cl ose, the sea l - i n u n it p i cks u p a n d
sea l s i n . W h e n t h e sea l-i n u n it p i cks u p , it ra ises a targ et i nto view, wh ich latches u p a n d
rem a i n s exposed u nti l released b y pressi ng a button beneath t h e lowe r-left co rn er o f t h e
cover.
The case is su itable for either su rface or sem i -flush panel mounti n g and a n assortment of
h a rdware is provided for either mou nti n g . The cover attaches to the case, and ca rries the
reset mech a n ism when one is req u i red. Two of the cove r screws h ave provision fo r a
sea l i n g wi re.
The case has studs or screw co n nections at both ends (IAV53 K, L. M, or N) or at the botto m
o n l y (IAV5 1 and 52A, and IAV53A, B , C, and D) fo r the exte rnal co n nections. The el ectrica l
con necti ons between t h e rel ay u n its a n d the case studs a re made thro u g h spri n g-backed
contact f i n g e rs mou nted in stationary molded i n ner and outer blocks, between w h i ch nests
a remova ble co n n e ct i n g p l u g (two pl u g s for the I AV53 K, L, M , a n d N m o d e l s) t h at
co m p l etes the ci rcu its. The outer blocks, attached to the case, h ave the studs fo r t h e
external con nections, a n d t h e i n n er blocks have the term i n a ls fo r t h e i ntern a l con n ectio n s.
The relay mech a n ism is mou nted in a steel framework ca l led the crad le and is a com p l ete
u n it, with a l l leads bei n g term i n ated a t the i n ner block. This cradle is held firmly i n t h e case
by a latch at the top and bottom and by a g u ide p i n at the back of the case . The cases a n d
crad les a re so constructed that the relay can n ot b e i nserted i n the case u pside d ow n . T h e
of the crad le and case, a lso locks the latch in place. The cover, w h i ch is fastened to the case
by th u mbscrews, holds the con n ecti n g p l u g i n place.
To d raw out the crad le from a sing le-ended case, the cover m u st fi rst be removed . T h e n the
con nect i n g plug ca n be d rawn out. I n so doing, the tri p ci rcu it is fi rst opened, then the
G E H- 1 81 4
&
D a re in sing le-end cases, the IAV 5 3 K, L, M, and N rel ays a re in the
CONSTRUCTI ON
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