GE AK-1-15 Maintenance Manual

hig h- set instantaneous spring (21). When a mag-
netic
force greater than the restraining spring
force is produced by an over -· current condition, the
armature (22) is pulled upward against the magnet
(24),
thus tripping the breaker by the moveme11t of
the connecting rod (13) against the tr ip paddle(l4).
The pickup value of the device may have one of
the following ranges: 4 to 9, 6 to 12, or 9 to
15
times coil rating. Three calibration marks will
appear on the calibratio n scale (18) and the
v alue of these calibration marks will be indicated
by
stampings on the scale as follows: (4X -
6.5X - 9X)
or {6X - 9X - 12X) or {9X - 1 2X -
15X), depending
on the desired range. To set the
device at a particular pickup value , loosen the
clamping nut (20) and slide the index pointer
on the calibration washer (l~! LO a position which
lines up horizontally with the desired pickup value
on
the calibration scale (18).
lo w- set, A dj ustable
If the characteristic of the device is low- set,
adjustable instantaneous, a link is installed in
place of spring (21). and th _e instantaneous calibra -
tion
spring is located where ~prin_g (15} is shown
in Fig. 26. Dashpot (17) isomittedfrom assembly.
REPLACEMENT (Fig. 26)
1. Disconnect trip paddle (14) and connecting
rod (10) by taking out cotter pin and removing
coupling
pin .
•
.
+
+
II
10
9
8
7
6
15
Low Voltage Power Circuit Breakers GEK-7303
2. Remove clamp (19) by loosening locking
nut and unscrewing
slotted stud.
3. Remove stud (23) .
4. Remove two
screws fastening magnet (11)
to lower stud.
5. Device is now free of breaker. Reassembly
is accomplished by revers ing the procedure.
When reassembling the magnet to the lower
stud , be sure to replace any spacing washers in
the same location in which they were found during
disassembly. If this is not done, misalignment and
consequent malfunction may
result .
ADJUSTMEN TS (Fig. 26)
Before the EC
-l B overc ur rent device is cali -
brated at the factory, the air g-aps between magnet
{11) and armatures (1 and 22) are set. These
gaps are measured at their widest point, between
the
front edge of the armature and magnet. The
o-ap for the short time delay armature is 1 7/64 in .,
and
for the long time delay armature is 17/64 in .
Both have a
plus and minus tolerance of l /64in .
The
air gap setting is a factory adjustment
and
is not to be attempted in the field. If any change
occurs, the calibration of. the device will not be
true . If any calibration difficulties are experienced,
they may
be due to the fact that the air sap setting
24
~
. --
l t
. , . I
i I ·
.
-rttl
! _l.l..i 23
22
21
20
19
18
5
16
17
2
3
SHO RT TIME
I. S. T. 0. AR MATURE
2. PALLET
3.PIN I ON
4, ESCAPE WHEEL
5. DRIVING SEG M ENT
6. S. T.O. CALIBRATION SPRING
7. S.T.O. TRIP ADJ.
8. TRIP LI NK
4
9. AIR GAP AOJ.
10. CONNECTING ROD
II. MAGNET
12. LOCK HUT
13 . CONNECT I NG ROD
14 . TRIP PADDLE
15 . L.T.O. CAL IBRATION SPR I NG
16. CALIBRATION CLAMP NUT
EC -I B a ADJ .
HIGH-SET INST .
ll OASHPOT
18 . CALIBRATION SCA LE
19. CALIBRATION WASHEii
20 . CLA NPINO NUT
ti . INST. CALIBRATION SPIII NO
22. L. T. O. ARNATUIIE
23 , ST UD
24 . N AON ET
Fig . 26 (Ol33C9022) Direct -acting tripping device EC - lB
27

GE AK-1-15 Specifications

General

Brand	GE
Model	AK-1-15
Category	Circuit breakers
Language	English