GE AKR-30 Series Maintenance Manual page 48

1 0.2.1 REPLACEM ENT O F CU R RENT
SENSORS
Referri ng t o F i g . 63, replacement o f i nd ividual SST
current sensors is accomp l ished as follows:
a) Disconnect the breaker harness from the tap ter­
minal board, removing cable ties as necessary. U n·
fasten the term i nal board from the breaker base.
b) At the rear of the breaker, remove the two Allen
head screws to separate the stud connector from the
contact pivot block.
c) Loosen the clamping bolt and remove the stud
connector. Li ft out the sensor and It� tap term i nal
board.
The sensor may be prevented from s l i pping off the
sensor stud by adjacent accessories.
the sensor stud m ust be removed from the breaker
base. The stud assembly is secured to the base with
four bolts which are accessible from the rear of the
breaker.
FIG.
48
If t h i s exists,
1 .
Flux shift Trip Device
2 .
A llen-head Screws
3.
Stud Connector
4 .
63
Current Sensor
AKR-SA-30 B R EAKER WITH SST TRIP DEVICE
-
d) When rep laci n g the stud connector, tighten the
Allen head screws to 250
c lamping bolt as fol l ows:
AKA 30/30H - 1 20
AKA 50/50H - 470
AKRT 50/50H - 470
1 0.3 FLUX S H I FT TRIP DEVICE
T h e F l u x Shift Trip device i s a low-energy, elec·
tromagnetic device which, u pon receipt of a trip
s i gnal from the programmer u n it, tri ps the breaker by
actuating the trip shaft.
The mounting arrangement of this component is I I·
l ustrated in Figs. 64 and 65. An electromagnetic ac·
tuator located on the u nderside of the front frame i s
coupled t o the breaker's trip shaft via a trip rod driven
by the actuator arm. The actuator i s a solenoid whose
armature i s spring-loaded and held in its normal
(Reset) position by a permanent magnet. In this state
the spring is compressed.
5.
Tap Terminal B>ard
6. Progr ammer Unit
7 .
Clamp Bolt
8. Sensor Stud
±
10 i n·l bs. Tighten th6
±
10 i n· l bs
±
1 0 i n· l bs
±
1 0 i n· l bs