GE AKR-30 Series Maintenance Manual page 43

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 involved is pushed.
The breaker should not be reclosed, of course, until the
opened fuse is replaced.
Type D breakers use the Open Fuse Lockout (OFLO)
shown in Fig. 55. Type A and B breakers use the OFLO
shown in Fig. 56. Both OFLO's work on the same design.
When the fuse opens, the resulting open circuit voltage
activates the OFLO's phase solenoid when the voltage
level reaches approximately 90 VAC. The solenoid's arma­
ture then drives a tripping rod against a trip paddle which is
attached to the trip shaft. This causes the breaker to open.
The armature also drives the reset button forward indicat­
ing what phase is involved. The reset button linkage also
holds the tripping rod against the trip paddle. The button
must be pushed in to release the tripping rod.
9.3.1 TYPE A AN D B BREAKER OFLO
ADJUSTMENT
To adjust the Type A and B breaker OFLO (Refer to Fig
56) :
a ) Back off tripping rod s o that it will not hit the trip
paddle when a solenoid is activated.
b) Using the maintenance handle, close the breaker.
c) Manually close the Left pole armature. Screw tripping
rod forward until it moves the trip paddle enough to open
the breaker. Add two full turns.
d) Close the breaker.
e) Manually 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 OFLO, 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"
overtravel after tripping rod trips breaker.
m m t m u m
i) Hold tripping rod in position and ttghten its locknut.
FIG. 55- TYPE D B R EAKER OFLO DEVICE
9.3.2 TYPE D B R EAKER OFLO
ADJUSTMENT
To adjust the Type D breaker OFLO:
a) With the breaker in the CHARGED position and the
OFLO reset, adjust the dimension between the end of the
tripping rod and the trip paddle to .062"
b) With the OFLO energized, the breaker must TRIP
and the R ESET button must move forward to the front
plate. In this condition, the breaker must be held trip-free.
• .093".
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