GE AKR-30 Series Maintenance Manual page 226

1 0. 2 . 1
R E P LAC EM ENT O F C U R R E NT
S E N SO R S
Referri ng t o F i g . 63, re p l acem e nt o f i n d i v i d u a l SST
c u rre nt sen sors i s acco m p l i s hed as fo l l ows:
a) D i sconnect t h e breaker harness from the tap ter­
m i n a l board , remov i n g cable t i e s as necessary. Un­
fasten the term i n al board from t h e breaker base.
b) At the rear of the breaker. remove the two A l l e n
he ad sc rews to sep arate t h e stud con n ector from t h e
con tact p i vot b l ock.
c) Loosen the c l a m p i n g bolt and remove the stud
con nector. L i ft out the sen sor and i ts tap term i n al
board .
The sensor may be p revented from s l i p p i n g off t h e
sen sor s t u d b y adj acent accesso ries.
the sensor stud m u st be removed from the breaker
base. The stud asse m b l y i s secu red to the base w i t h
fo u r b o l t s w h i c h are acces s i b l e from t h e rear o f t h e
breaker.
FIG. 63 - AKR-SA-30 B R EAKER WITH SST TRIP DEVICE
48
I f this exists,
1 . Flux shift Trip Device
2 . Allen- head Screws
3 . Stud Connector
4 . Current Sensor
d) When re p l ac i n g t h e stud connector, t i ghten t h e
A l l e n head sc rews to 2 5 0 ± 1 0 i n - l bs. T i g h ten t h e
c l a m p i n g bo l t a s fol lows:
AKR 30/30H - 1 20 ± 1 0 i n - l bs
A K R 50/50H - 470
A K RT 50/50H - 470 ± 1 0 i n- l b s
1 0 . 3
F L U X SH I FT T R I P D EV I C E
T h e F l u x Sh i ft Tri p device i s a l ow-e nergy, e l ec­
t ro m ag n e t i c device w h i c h , upon rece i pt of a tri p
s i g nal from t h e p rogram mer u n i t , t r i p s t h e breaker by
act u at i n g the t r i p shaft .
The m o u n t i n g arrangement of t h i s c o m ponent i s i l ­
l u strated i n F i g s . 6 4 and 65. A n e l ectro m ag n e t i c ac­
t u ator l ocated on the u n derside of the front frame i s
cou p l ed t o t h e breaker's t r i p shaft v i a a tri p rod d riven
by t h e actuator arm. The actuator i s a solenoid whose
armat u re i s s p r i n g - l oaded and held i n i t s norm a l
(Reset) pos i t i o n b y a permanent mag net. I n t h i s state
the s p r i n g is com p ressed .
5 . Tap Ter minal Board
6. Programmer Unit
7 . Clamp Bolt
8 . Sensor Stud
:t:
1 0 i n- l bs