Westinghouse DK-15, Manual

Page: 47 / 96

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Type
DK- 1 5
and
DK-25 Air Circuit
Breaker
General
The DK air circuit breake r, c omple te with all attachment s , is a
s e l f - c ontained unit , and has been moun te d , ad jus ted and calibrated on i t s
own permanent pane l a t the fac tory . I t i s de s igned only to b e mounted i n a
vertical po s i tion , and a l l inspe c tions for proper operation mus t be made
with the breaker main pane l held vertically .
Unpacking
Care mus t be exe r c i sed when unpacking to make sure that no parts
are broken or damaged , and an inspe c t ion should be made immediate ly to
che ck for any damage in transi t . A l l du s t and d irt should be careful ly
blown out o f the c omple te a s sembly, e spec ially in the c l o s ing t oggle link­
age overload a t ta chments and such o the r attachment s a s are suppl ied .
I t i s not advisab le to lubrica te any parts o f the breaker . The
lubrication supplied during fac tory as sembly, where nec e s sary , is a spe c ial
f orm of grease which i s used sparingly .
Thi s wil l be found suffi c ient for
years o f serv ic e . A dditional o i l wi ll only promote the a ccumulation of dust
and dirt .
In new ins talla tions , the breaker mus t be careful ly pro te cted
from pla s te r , c oncrete and o ther fore ign gritty partic l e s that may add
fric tion to the moving part s in the t oggle linkage .
Inspection
F inal inspe c tion should preferably be made with the breaker in
i t s permanent mounting , but if thi s i s impo s s ible , it can be s e t up rigidly
in a ve rtical pos ition while the inspe c t i on i s made .
R o tate the manual o perating hand le s l owly in a c lockwi se dire c ­
t i on t o move the c ontac t s toward the c l o sed p o s i tion . Che ck the movement
of each arc tip through the throat of the 11De - i on11 arc inte rrupting chamber
to
make sure tha t the tips d o not rub agains t the c eramic s ide plate s .
C ontinue the c l o s ing mot i on until the moving arc tips j us t t ouch the s ta­
tionary arc tip s . Che ck the main c ontac t s e para t i on a t approximate ly
1/8
inc h, as shown on F ig s .
2
and
3 .
C ontinue the hand le rotation to the fully
c lo sed po s ition and watch the main c ontac t over travel as evidenced by rotary
mo tion away from i t s s to p , ad jacent to the s e c t i on where the shunt is
a ttached .
R eturn the manually ope rated hand l e to the neutral po sition and
r otate c ounte r c l o ckwi se t o trip the breake r . The toggle linkage should
c ollaps e and the moving c onta c t a s sembly mov e fre e ly to the ful l open p o s i ­
tion .
This i s followed immediately by c ompl e te re s e tting o f th e links in
the toggle me chani sm . This re set t ing operat i on is a c c ompli shed ent irely by
gravity . For thi s rea s on the links mus t always be free to move without
f ri c t i on or binding .
Adjustment of Contacts
The arc tip ad jus tment should be made a s shown in Figs .
2
and
3 .
There i s n o ad justment provided for the main c ontac t s , and under ordinary
c ircums tance s the se main c onta c t s will la s t the life of the breaker without
repair other than o c ca s ional c leaning . Both main a nd arc ing contac ts are a
high s ilver a l l oy .
Replacement of Contacts
The sub - panel , barrier and "De - i on " inte:rrupting a s s embly may b e
removed as a uni t by taking out t w o b o l t s at the outer ends o f the sub -panel .
Thi s give s a c c e s s to the c ontact s for easy insp e c t i on or replacement .
1
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