GEK-49861
ope r a t i ng on a fau l t .
An app rop r i a t e s e t t i ng i s u s ua l l y between t wo
and fou r cyc l e s p i ckup t ime .
The se t t i ng s a r e made by pot ent i ome t e r s
o n the SP c a r d .
An "OSB" plug a r r angemen t i s provi ded o n the SP
ca r d .
When th i s plug i s i n the "IN" pos i t ion,
the ma i n o u tp u t
con t a c t s a r e b locked f rom t r ipp i ng du r i ng the ou t -o f - s t ep cond i t ion .
When the p l ug i s i n the "OUT" pos i t ion, the ma i n ou tpu t con t ac t s a r e
not blocked so that a n ou t -of-s t ep cond i t ion me r e l y c lo s e s a r eed
r e lay con t a c t between s t uds 7 and 8 .
CONSTRUCTION
The t ype SLY81 r e lay i s assembled i n a deep, l a r g e s i z e, doubl e
end ( L 2 D) d r awou t case hav i ng s tuds a t bot h ends i n the r e a r for
e x t e r na l connec t ions .
The e l e c t r i ca l conne c t ions between the r e lay
u n i t and the case s t uds are made t h rough s t a t iona ry molded i nne r and
ou t e r bloc k s be tween wh i ch nes t s a r emovabl e connec t i ng plug wh i ch
compl e t e s the c i r cu i t s .
The ou t e r bloc k s a t t ached to the c a s e have
the s tuds for the e x t e r na l connect ions, and the i nner bloc k s have the
t e rm i na l s for the i n t e r na l connec t ions .
Eve r y c i r cu i t i n the d r awout case has an aux i l i a r y b r u s h,
a s
s hown i n F i g u r e 2 0, t o prov ide adequate ove r l ap when t h e conne c t i ng
p l ug
i s w i t hdr awn o r i ns e r ted .
Some c i r cu i t s a r e equ ipped w i th
s ho r t i ng ba r s ( see i nt e r na l connect ions i n F i g u r e 2) and on t h e s e
c i r cu i t s, i t i s e spec i a l l y impor tant t h a t t h e aux i l i a r y b r u s h ma k e
con t a c t a s i nd i ca t ed i n F i g u r e 20 w i th adequ a t e p r e s s u r e t o p r ev e n t
t he ope n i ng of impo r tant i n te r lock i ng c i r cu i t s .
The r e lay i s mounted i n a s t e e l f r amewo r k cal l ed the c r ad l e and
i s a comp l e t e u n i t w i th all leads t e r m i na t ed a t the i nne r block s .
Th i s c r ad l e i s h e l d f i rmly i n the case w i th a l a t ch a t bot h top a nd
bot tom and by a g u i de p i n a t the back of the case .
The conne c t i ng
p l ug,
b e s i d e s
m a k i ng
t h e
e l e c t r i ca l
conn e c t i o n s
b e t w e e n
t h e
r e spec t i ve bloc k s o f the c r adle and case, a l so loc k s the l a t ch i n
place .
The cover, wh i ch i s d r awn to the case by t humb s c r ews, ho l d s
the connect i ng p l u g s i n place .
The t a r g e t r es e t mecha n i sm i s a pa r t
o f the cover a s s embly .
The
relay
case i s s u i t able for
e i t he r
s em i f lu s h o r
s u r face
mou n t i ng
on a ll
pane l s up to two
i nches
t h i c k and app rop r i a t e
ha r dwa r e i s ava i lable .
Howeve r, panel t h i c k n e s s mu s t b e i n d i ca t ed on
the r e lay order to ensu r e that p rope r ha r dwa r e w i l l be i n c luded .
Out l i ne and panel d r i l l i ng i s shown i n F i g u r e '22 .
Fo r DC s uppl y
vol tages g r ea t e r t han 1 2 5 vol t s i t i s nec e s s a r y to u s e an e x te r na l
p r e - r eg u l a to r .
The p r e - r egu lator i s packaged i n a box made f rom
compou nd p l a t e s and pe r forated s t e e l s i d i ng .
It can be mou n t e d on
the r ea r of the r elay or a t a conven i e n t loca t ion nea r the r e lay .
The ou t l i ne and mou n t i ng d imens ions for the p r e - r eg u l a to r a r e s hown
i n F i g u r e 3 0 .
A
s epa r a t e
t es t i ng
plug
can be
i n s e r t ed
i n p l a c e
o f
t h e
conne c t i ng plug t o t e s t t h e r e lay i n place o n t h e panel e i t h e r f rom
i t s own sou r c e of cu r r ent and vol tage, or f rom other sou r ce s .
The
r e lay can be d r awn ou t and r eplaced by anothe r which has been t e s t e d
i n the l abo r a to r y .
15
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