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Undervoltage Tripping Attachment
to the l ef t
trip bar if
vol tage .
f r om the hold ing c oi l s ,
c l o s e the breaker .
magne t under a c t i on of the spr ing in the f l exib l e l ink .
trip by thi s dead push .
sho r t ening or lengthening the flexible l ink d e t a i l .
t r ipping f e a ture ,
when the above ad j us tment i s che cked .
t o the l ine s ide o f the b reaker .
Reverse Current Attachment
breaker when the dir e c t i on
atta chment c on s i s t s
energized by a current c oi l
the s e r i e s c oi l
tend s t o r o t a t e but is
ver s ed the armature
to t r i p the breake r .
pl a t e a t
ra ting .
by opening
the v o l t ag e c oil through an auxil iary swi t ch on the breake r .
Field Discharge Switch
two pole breaker in the s p a c e l e f t vac ant ab ov e the breake r t oggle l inkag e .
Corr e c t ad jus tment in one dir e c t i on
c ontac t
mo t i on .
part
mor e
Auxiliary Switch
..
a s sembly supplied in e i the r
of the ma in bre aker frame .
s e c t i ons which carry
c onta c t i s a s ilver bridging membe r ,
w i th an
place when the switch c on ta c t i s made .
s embl ed
a s s embl y through wiring hol e s t o the rear of the main pane l .
two 11break 11
bar and inve r t ing the bridging memb e r ,
rangement .
Type DK- 1 5 and DK-25 Air Circuit Breaker
The underv o l t age a t ta chment i s normal ly mounted on the main panel
of the breake r .
the c ontrol
To chec k the a d j u s tment
hold the armature again s t the magne t by hand ,
Now allow
When the undervoltage a t ta chment
the o il d a s h pot should be removed by uns c r ewing the p o t
The r ever s e current a t t achment
of a magn e t energi zed by a v o l t age c o i l and an armature
current i s fl owing
r e s trained by a s t op . When the s er i e s current is r e
i s r o ta ted i n the opp o s i t e dire c t i on
Thi s a d j u s tment i s c a l ib r a t e d and marked on the s cale
1 0 % , 1 5 % , 2 0%
and
The rever s e current armature
the v o l tage c o i l c ircui t .
Th e f i e l d d i s charge c onta c t
j u s t pri o r
to
the a r c tips
Similarly,
the swi t ch mus t make c ontac t b e f o r e the b r e aker c onta c t s
1/8"
than
during the opening mo tion
DK
The
auxi l iary
the
e c ce ntric rolling
The t e rminal s cr ews are readily
b reaker and
adequate
E a ch four poin t swi t ch
c ontac t s , but any pole may b e r ev e r s ed
I t oper a t e s
to
vol tage drops
t o a value of
of thi s a t t achment ,
the armature
Ad j u s tment to provide
Always c onne c t the underv o l tage c e l l s
(
Fig .
of current flow in tha t pole i s rever s ed .
in s er i e s wi th one pole of the b reaker .
in the proper
25 %
rever s e current ,
i s r e s e t a f t er a t r i pping ope r a t i on
Thi s c an be a c c ompl i shed
(
Fig .
i s eviden c ed b y opening
t ouching during
in
sw i t c h
shown
4
to
8
pole s and is
Each pole c o ns i s ts
terminal s c re w s on the reve r s e
s p ring mounted on the
m o ti on such
that adequa te w iping
a c c e s s ib l e on the c ompl e tely a s
wi ring s pa c e
i s no rma lly H s s e!ll b l e d wi th two "make 11 an�
thu s making p o s s ib l e any d e s i r e d ar
5
trip
the br eaker through the
35%
to
r emov e the v o l t age
to move s lowly a.way
The breaker should
thi s o p er a t i on
i s furni shed w i th
12-13 )
i s u s ed
dire c t i on
again s t a s pring
b a s ed on normal
13-14)
i s normally mount ed on a
the b r e aker
r
a
e
o f the b
e
k
r .
9
Fig .
i s a
c ompac t
rigid ly mounted on the
of
tw o s ilve r po s t s
s ide .
s l id ing bar,
i s provided
f r om the
by r emoving the s li d ing
60%
of
r a t ed
and
from the
i s made by
a t ime delay
to trip the
The
When
the armature
current
by wiring
o f the swi tch
c l o s ing
molaed
s ide
in
the
The moving
and
a c t i on take s
swi tch
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