Westinghouse DK-15, Руководство пользователя

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Type
DK-1 5
and
DK-25
Air Circuit Breaker
.
The me chan i sm crank engag e s a hardene d s t eel cam on the roller
l ever . The relative motion of the crank r o ller wi th re s p e c t t o thi s cam
surfa c e i s to pr oduce the maximum me chani cal advan tage when the cl o s ing
load is grea t e s t . A limi t swi t c h s egment on the me chan i sm c rank shaft
p o s i tively carr i e s the crank r oller pa s t the cam a f t er a c l o s ing op era t i on ,
s o tha t the br eaker can b e c l os ed e i ther manually or e l e c tr i cally wi thout
interference or me chani cal di s engagemen t . The only r equirement i s that the
limi t swi t ch mus t be all owed to cu t off the motor c l o s ing curren t .
One adj u s tment b e tween the mot or me chani sm and the br eaker r o l l er
l ever should b e checked f or proper operat i on . C l o s e the br eaker manual l y
and r o ta t e t h e m o t o r by hand . T hi s i s done by removing the p la t e a t the
l o�er end and r o ta t ing the arma ture in the dir e c t i on of the arr ow , un t i l
the crank r o l l er i s jus t pas s ing o ver the hee l of the cam . There s h ould b e
from
1/64
t o
1/32
inch c l earanc e b e twe en the r o l l er surfa c e and the oam
surfac e at thi s p oint . If binding o c curs, the minimum c l o s ing v o l tage will
b e unduly high , and i f too much c l earan c e is pr e s ent , the me chan i sm may
fa il t o move the breaker t oggl e l i nkage t o the c omp l e t e l y c l o s ed p o s i ti on .
Thi s adj u s tmen t i s ma intained by a dding or taking out a spac er b e tween the
molded t i ebar and the c a s t r ol l er lever on the right s id e .
The mo tor c l o s ing current i s g iven in the fo l l ow ing tab l e for
s tandard. c on tr o l v o l tage ra t ings :
V ol Rat ing
1 1 0
V o l t , A- c .
2 2 0
V o l t , A- c .
12 5
Vol t ,
D- e .
2 5 0
Vol t ,
D- e .
Shunt Trip Attachment
C l o s ing Current
at Normal V o l tage
30
Amp er e s
15
Amp er e s
30
Amperes
1 5
Ampe r e s
The s hunt trip a t tachment , w he n supplied , i s mounted rigidly t o
the breake r frame behind the fa ce p la te . The trip bar bracke t i s a ttached
t o i t s l ow e r end . When the shunt trip i s no t supp lied , i t s p lac e i s t aken
by a l ong trip rod he ld by a c a se identical
in
out s ide appearance w i th the
s hunt trip ca se . Both type s are inte rchangeab1e and can
be
read ily remove d
and re place � .
In
replacing the shunt trip a s s embly, make sure the moving
c ore and t rip rod a s sembly is free to move without binding a ga ins t the guide
holets or c o il .
The shunt trip i s de s i gned for int ermi t tent duty . The t ripping
curr en t mu s t always b e cut off by an auxiliary swi t ch on the breaker . The
normal tr ipping current s for s tandard c ontrol voltages ar e :
V ol tage Rating
110
V o l t , A- c .
2 2 0
Vol t , A - c .
1 2 5
V ol t ,
D- e .
2 5 0
Volt ,
D- e .
Wiring Diagram
Tripp ing Curren t
7 Amperes
4
Amp er e s
2 . 5
Amp ere s
1 . 5
Amper e s
The s tandard wiring diagram f or the mot or me chan i sm and s hunt
trip a t tachment s are given i n Fig .
1 0 .
The motor c ontrol c i r cui t can b e
supp l i ed with a spec ial r elay a s a n i ntegral part of the e l e c tr i ca l ly oper­
ated breaker tha t preven t s r e c l o sure un t i l a f t er the ex t ernal c on tr o l
swi t ch ha s b e e n opened . S e e Fig .
8 .
Thi s pr eve n t s t h e breaker from pumping
i f c l o s ed agains t a high overloa d or s hor t circui t . A · further featur e of
the c ontrol wir ing is the preventi on of e l e c trically inching the breaker
c l os ed af t er the moving c ontac t a s s emb ly ha s s tarted to c l os e .
4
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