GEI-86134, Power Circuit Breakers
CONTACT REPLACEMENT Types AKR-30, 30H
and AKRU-30
The stationary contacts (arcing and mains) of the
AKR-30 breaker frames are replaced in identical
fashion to that employed for the intermediate and
main stationary contacts of the AKR-50. To do so,
however, it is necessary to first remove the arc
runner by removing its three holding screws.
Replacement of the single movable contact arm
is accomplished in like manner employed for the
AKR-50 breakers, i.e., remove and replace the
coupling pin, pivot pin, etc., as described below.
CONTACT REPLACEMENT Types AKR-50, SOH,
AKRU-50 and AKRT-50
Referring to Fig. 17 of GEK-7310A, arcing con
tacts (1) are released by removing the arc runner
(5) and the arcing contact pivot (6) . When reassem
bling, make sure that the insulating spacers on the
ends of the arcing contact pin (7) and the insulating
washers (8) under the lower arc runner fastening
screws are replaced.
Intermediate (2) and main contacts (3) are re
moved by disconnecting their springs. The end
pieces on the springs (9) have a small hole for in
serting a spring puller. While holding the contact,
pull the spring and lift it off the end of the contact.
Replace the contact by holding it in position (inner
end behind the contact stop) while extending and
engaging the spring on the outer end. A suitable
puller can be fashioned by forming a hook on the
end of a length of 1/16-inch diameter steel wire.
The two movable contact arms (4) are removed
by drifting out pin (10) connecting them to the in
sulated coupling (11). Right angle tru-arc pliers
are needed to remove and replace the tru-arc re
tainer on the end of the pin.
Next, remove the fastening screws, washers,
springs and pivot pin from the pivot below. When
replacing the arms ensure that all spacers, springs
and washers are returned to their original position.
Tighten the two bolts in the contact arm pivot.
AKRU-30 and -50 FUSED BREAKERS
Except for the open fuse lockout device and the
integrally-mounted fuses on the upper studs, the
AKRU-30 and -50 breakers are identical to the un
fused AKR-30 and -50 models. Overcurrent trip
devices are the same for both types.
Fuse Sizes and Mounting
Table 3 lists the range of fuse sizes available
for these breakers. The Class L fuses are mounted
as shown in Fig. 10. Other than the 800A size,
which has a single mounting hole per tang, each L
fuse tang has two holes sized for one-half inch bolts.
Class
J
fuses rated 300 thru 600A have one
mounting hole per tang. The 300, 350 and 400A
sizes require copper adapter bars per Fig. 11.
TABLE 3
GE CLF FUSES FOR AKRU BREAKERS
NEMA
Melting
Fuse
Breaker
Time-
Class
Type
Ampere
Cat. No.
current
6 00V
AKRU-
Rating
Curves
60 Hz
30 50
--
300*
GF8B300
GES-8004
350*
350
I
--
I
�
-
-
400*
400
I
450
450
I
500
500
600
600
800
800
GES-8005
[L
1000
1000
I
1200
1200
I
1600
1600
--
2000
2000
'3pecial
--
2500
G F9 F2500AK
183B7832
*Mounting adapter required - see Fig. 11
10
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