GE AKR-30 Series Maintenance Manual page 202

SECTION 7 -Breaker Maintenance (Cont.)
�
\TRIP
SHAFT
7.8.2 OPERATIONAL CHECK
(BREAKER WITH UV DEVICE INSTALLED)
Check the pickup and dropout values at room tempera­
ture. See table 25.
Check the positive trip ability as follows:
armature closed , close the breaker. Insert a 0.032
inch shim (wire gage or flat stock) against the armature
open stop (see Fig. 32D) and release the armature. The
breaker must tri p .
7.8.3 ADJUSTM ENTS
If the operational checks (7. 8.2) indicate that ad just­
ments are necessary, these procedures should be followed:
tri p latch
Fi rst verify engagement
tion 7. 1 5, and verify that the trip shaft torque req u i red to
tri p a closed breaker is no greater than 24 i nch-ounces.
Then proceed as follows:
PICKUP VOLTAG E:
The Q.i.Q.!s.!,m level is changed by turning the adjustment
screw shown in Fig. 32A. The screw is secured by either
a locking wire or a jam nut inside the frame. Devices with
a jam nut requ i re removal of the device to make this
oq
adjustment. The pickup voltage at room temperature
(approx. 2 0-24 should be 85 % or less of coil rating and
should be measured at the secondary d isconnects with
the coil energized. Not e
between the armature and magnet initially to 0.030 inch
using the closed gap ad justment screw shown in Fig. 32C
before making pickup adjustments.
Be sure to secu re the pickup adjustment screw with the
jam nut or lockwire.
24
FIG. 31 - 2N D
UN DER VOL TAG E DEV ICE
With the
±
as described i n sec­
:
On DC devices set the gap
DROPOUT VOLTAGE:
On AC devices the dropout level will fall within the
requ i red limits (30 % to 60% of the coil rating) if the picku p
is set properly. On DC devices, the d ropout level may
need independent adjustment.
after the pickup level has been established per the above
procedure. If requ i red , use the closed gap adjustment
screw shown in Fig. 32C to obtain the d ro pout setting. A
gap must remain between the armature and magnet on
DC devices to prevent sealing in u pon loss of voltage.
Secure the adjustment screw with the locknut and apply
RTV to the locknut.
POSITIVE TRIP:
Check positive trip abi lity per 7.8.2. Adjust the trip
paddle screw if necessary to assure positive trip. With the
u � dervoltage device closed (picked up), and the mecha­
msm reset, there must be clearance between the trip
paddle and the device armature. If clearance adjustment
is necessary, re-verify positive trip abi l ity.
. 005
FIG. 32A ­
U NDERVOLTAGE DEVICE
7.8.4 FACTORY SETTINGS
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This section covers certain factory settings as an aid to
rouble shooting. They are for reference only, and are not
mtended to be field ad justed. They should not be consid­
ered criteria for acceptance or rejection.
ARMATU RE LOCATING R IVET:
The rivet shown in figure 32A serves as a locater for the
armature. A clearance of 0.001 to 0.01 0 inch should exist
between the rivet and armature as shown in fig. 32A. The
rivet should be able to turn freely.
AR MATU RE OPEN GAP:
The air gap between the armature and the magnet with
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he device � -energized should be approximately 0 .250
tnches. Thts ts, checked by inserting a 0.201
diameter gage pin between the armature and magnet as
shown in Fig. 328.
This is accompl ished
R I V ET
.001 "
.01 0 "
HOLDING
±
.005 inch