GEK- 49848A
Contact
To fac i l i tate adjustment of contac ts, remove the red jum per l ead ( s ) from
termi nal s s hown i n the a ppl i ca bl e i n te rnal connec t i o n s d i a g ram and use a neon
i nd i ca t i n g l am p i n s e r i e s w i th a n AC v o l ta ge sup p l y a c ro s s termi nal s 19 a nd 20 a�d,
i f a ppl i cabl e, 18 a nd 1 9 to s i gn i fy al l contact c l o sures . Refer to Fi g . 1 9 a nd F1g .
20 for i dent i f i c at i on o f l ow gra d i en t and barrel contac t parts res pec t i v eJy a nd
proceed a s fol l ows:
Loo sen s l i ghtl y the l ocknut wh i c h secure s the backs to p screw ( l ocated a t the
r i ght fro n t corner o f the un i t ) to i ts suppo rt . Unwi nd the backs top sc rew so that
the mov i ng contact a rm i s permi tted to sw i n g freel y . Adjust the ten s i on of each l ow
gra d i en t contac t brus h so that o ne- to- two grams of pressure a re requi red a t the
contac t t i p i n order to cause the end of the brus h to s e para te from the i nn e r face
o f i ts respec t i v e brush re ta i ne r . Adjust the s pi ral s pri n g unt i l the mov i ng contact
a rm i s in a neutral pos i ti on, i . e . , wi th the a rm po i nt i n g d i rec t l y forwa rd . Loosen
the l ocknut wh i ch secures the l ow gra d i ent s ta t i onary con tact moun t i n g sc rew to the
sta t i onary contact support .
Wi nd the moun t i ng screw i nward un t i l the l ow gra d i en t
s ta t i onary a nd mov i ng contact members jus t be gi n to touc h .
U nwi nd the moun t i ng
screw unti l the stati onary contact b rus h i s verti cal , w i th the stati ona ry contact
brush reta i ner down . Then t i ghten the l ocknut wh i ch s ecures the mount i n g sc rew to
the sta t i onary contact support .
Loosen s l i ghtl y the screw wh i ch secure s the barrel contact to i ts support .
Th i s sc rew s houl d be onl y l oose enough to a l l ow the ba rrel to rota te i n i ts s l eeve,
but not so l oose a s to al l ow the s l eeve to move w i th i n the support .
Wi nd the
backs top screw in unti l the l ow g rad i ent mov i ng and s tat i on a ry contact members just
begi n to touc h . Wi nd the ba rrel contact in unt i l the ba rrel contacts jus t begi n to
touc h .
Unwi nd the barrel contact 1/4 turn .
T i ghten the sc rew wh i c h s ecures the
barrel contact to i ts support .
U nwi nd the backsto p sc rew 2 3 turn .
T i ghten the
l ocknut sc rew wh i c h s ecures the backstop sc rew to i ts sup port . F i n a l l y, adjust the
ten s i on on the l ow grad i en t s ta t i on a ry contact brus h suc h that, when the l ow
gra d i ent contacts a re made a nd ful l y w i ped i n, there i s a pproxi ma tel y an equal
defl ec ti on on each brus h .
adjustments
are
Adjustment
The d i rec t i onal un i t is prov i ded wi th a notched core wh i ch i s used to m i n i m i ze
the torque produced on the rotor by current a l one i n the o perat i n g c o i l s w i th the
pol a r i zi ng c i rcui ts de-energi zed . Th i s adjustmen t i s made at the fac tory a nd may be
checked a s fol l ows:
Fi rst, s hort out the po te n t i a l pol a r i z i n g c i rcui t . Adjust the control s pr i ng
so that the mov i n g contact structure i s bal anced between the sta t i o n a ry contact and
the s to p . Th i s c a n be done by l oosen i ng the hexagonal - head l ocki n g sc rew, wh i ch
c l amps the s pri n g adjus ti n g r i n g i n pos i t i on, and turn i n g the ri n g to the l eft unt i l
the bal ance po i nt i s reac hed .
Energ i ze the o pera t i n g c i rcui t wi th 30 amperes a nd check that the contact a rm
does not mov e . The core shoul d be turn ed i n smal l steps unt i l a po i nt i s reached
where there i s no "b i as" torque from current a l one .
The c o re can be turned by
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