Replacement Of Current; 0.3 Flux Shift Tri P Device - GE AKR-30 Series Maintenance Manual

1 0.2.1 REPLAC E M ENT O F C U R R ENT
S E N SO R S
Referri n g to F i g . 63, rep l acement o f i n d iv i d u al SST
c u rre nt sensors is acco m p l i shed as fo l l ows:
a) D i s c o n nect the b reaker harness from the tap ter­
m i n a l board , rem ov i n g cable t i e s as necessary. U n ­
fasten the term i n a l board from the b reaker base.
b) At the rear o f the b reaker. remove the two A l len
head s c rews to separate the stud con nector f rom the
con tact p i vot b l ock.
c) Loosen the c l a m p i n g bolt and remove t h e st ud
connector. L i ft out the sen sor and its tap term i n a l
board.
The sensor may be p revented from s l i p p i n g off the
sensor stud by adjacent accessories.
the sensor stud m u st be removed from the b reaker
base. The stud asse m b l y is sec u red to the base with
four bolts w h i c h are acce s s i b l e from the rear of the
b rea ker.
FIG . 63 - AKR-SA-30 B R EAKER WITH SST TRIP DEVICE
48
If t h i s exi sts,
1 . Flux shift Trip Device
2. Allen- head Screws
3 . Stud Connector
4 . Current Sensor
d) When replac i n g the stud con nector, tig hten the
A l len head screws to 250
clamping bolt as fo llows:
AKA 30/30H/30L - 1 20
AKA 50/50H - 470
AKRT 50/5 0H - 470
1 0.3 FLUX S H I FT T R I P D EV I C E
The Flux Sh ift Tri p d evice is a low-energy, electro­
magnetic device wh ich , u pon receipt of a trip signal
from the p rogrammer u n it, trips the breaker by actuat­
i n g the trip shaft.
The mounting arrangement of this com ponent is
i l l u st rated in Figs. 64 and 65. An electromagnetic
actu ator located on the u n derside of the front frame is
coupled to the b reaker' s trip shaft via a trip rod d riven
by the actuator arm . The actuator is a solenoid whose
armat u re is spring- loaded and held in its normal
(Reset) position b y a permanent magnet . In this state
the s p ri n g is com p ressed.
5 . Tap Terminal Board
6 . Programmer Unit
7 . Clamp Bolt
8 . Sensor Stud
±
1 0 in-lbs . Tighten the
±
1 0 in-lbs
±
1 0 i n - l bs
±
1 0 i n - l bs