Introduction; Constructional Differences - GE AKR-4-30 Maintenance Manual Supplement

LOW-VOLTAGE POWER CIRCUIT BREAKERS

INTRODUCTION

The data in this supplement pertains to the new
800A AKR-30 and the
breakers not covered by the ex isting AKR/AKRU-50
maintenance manual (publication G EK-7310A) .
formation on the new ECS and SST solid-state trip
devices also is included.
The new breaker models are derivatives of the
16 00A frame AKR-50 design.
cific constructional differences identified below, the
basic AKR-50 framework, mechanism and accessory
devices are substantially common to all versions.
Ex cept for the 800A frame primary stud details,
W
the ex ternal H x x D dimensions are identical.
Accordingly, a majority of the AKR-50 information
now in publication G EK-7310A applies equally to the
new types. Therefore, to avoid needless repetition,
the scope of this supplement is confined principally
to that descriptive and instructional material unique
to the new models. Unless noted to the contrary,
or otherwise discussed herein,
continue to employ G EK-7310A as the general,
erational information source.
Complementing the above "new" material,
supplement includes additional information to ex ­
pand and updateex istingG EK-7310A subject-matter
where appropriate. Ex amples are revision of the
operating handle adjustment procedure and reduc­
tion of the AKRU-50 minimum fuse size from 800A
to 450A.

CONSTRUCTIONAL DIFFERENCES

The features which distinguish the new AKR/
AKRT breakers from the parent AKR-50 frame size
are listed below. For a detailed parts comparison,
refer to "Renewal Parts Bulletin" G E F -4527.
AKR-30.
a. An entirely new contact structure.
employs three stationary mains,
arcing and one movable contact arm.
b. Primary studs carry four disconnect fingers per
pole. See Fig. 1.
c. Two additional opening springs, one at each end
of the main shaft. See Fig. 4.
MAINTENANCE MANUAL SUPPLEMENT
TYPES AKR/AKRU-30/50, AKRT-50 PER TABLE
2000A AKRT-50 frame
In­
Apart from the spe­
the user should
op­
this
Each pole
two stationary
See Fig. 5.
Power Circuit Breakers, GEI-86134
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AKR-30H. Same as the AKR-30 ex cept for modifi­
cations in the following areas:
a. Arc quenchers.
b. Closing springs.
c. Ex tra insulation on shaft flyweights.
d. Mounts one additional stationary main contact
for a total of four; otherwise the contact struc­
ture is same as AKR-30. See Fig. 6 .
NOTE:
To visibly distinguish it from the
AKR-30, the closing springs and arc
quencher covers of the 30H are colored
red.
Fig. 1. Rear view of AKR-30 breaker
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