Open Fuse Lockout Device - GE AKR-30 Series Maintenance Manual

SECTION 9- Fused Breakers (Cont.)
9.3

OPEN FUSE LOCKOUT DEVICE

This device automatically trips the fuse breaker if one of
the fuses opens. When this happens, the breaker is locked
open until the reset button of the phase i nvolved is pushed.
The breaker should not be reclosed , of course, u ntil the
opened fuse is replaced .
Type D breakers use the Open Fuse Loc kout (O FLO)
shown i n Fig. 55. Type A and B breakers use the OFLO
shown in Fig. 56A & 56B. Both OFLO's work on the same
design . When the fuse opens, the resulting open c ircu it
voltage activates the OFLO phase solenoid when the
voltage level reaches approximately 90 VAC (the functional
test in the factory is accom plished using 1 2 0VAC}. The
solenoid armature then d rives a tripping rod against a trip
paddle wh ich is attached to the trip shaft. This causes the
breaker to open. The armature also d rives the reset button
forward i nd icating what phase is i nvolved.
button lin kage also holds the trip p ing rod against the trip
paddle. The button must be pushed in to release the
tripping rod.
9.3 . 1 TYPE A A N D B B REAKER O F LO
ADJUSTME NT
To adjust the Type A and B breaker O FLO ( Refer to Fig
56A):
a) Back off tripping rod so that it will not h it the trip
paddle when a solenoid is activated .
b ) Using the mai ntenance handle, close the breaker.
c) Manually close the Left pole armature . Screw tripping
rod forward u ntil it moves the trip paddle enough to open
the breaker. Add two full additional turns.
d) Close the breaker.
e) Man ually close the Left pole armature again . The
breaker must open and the reset button pop out. In this
condition close the breaker, it should trip-free.
f) Reset the O FLO , the breaker must now be able to
close.
g) Repeat for Center and Left poles.
h) Check for a . 1 25" minimum clearance between trip­
ping rod and trip paddle with the OFLO reset. Check for
.032" minimum overtravel after tripping rod trips breaker.
i ) Hold tripping rod i n position and tighten its lockn ut.
The reset
FIG. 55- TYP E D B R EAKER OFLO DEVICE
9.3.2 TYP E D B REAKER OFLO
ADJUSTMENT
To adjust the Type D breaker OFLO:
a) With the breaker in the CLOSED position and the
OFLO reset, adjust the di mension between the end of the
tripping rod and the trip paddle to .1 00" - . 1 40 " .
b ) With the O FLO energized , the breaker must T R I P
a n d t h e R ESET button must move forward t o the front
plate . In this condition , the breaker must be held trip-free.
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