GE AK-50 - Mechanism Part Replacement and Adjustment; Stored-Energy Mechanism Replacement; Mechanism Adjustments After Replacement; AKF Mechanism Description

GEI
-
74600
Low
-
voltage
Power
Circuit
Breakers
in
.
should
exist
between the
front of
the
groove
pin
and the
rear
surface of
the
Nylok
screw
head
.
Replacement
(
Fig
.
14
)
If
it
is
necessary
to
replace
any
of
the
mechanism
parts
,
the
following
total
procedure
is
recommended
.
This
procedure
may
be halted
at
the
step
required
to
replace
any
particular
part
:
FIELD
SWITCH
Other
adjustments
to
the
closing
and
operating
mechanisms
,
such
as
complete
contact
and latch
adjustments
,
may
be made
by following
the
pre
-
viously
described
instructions
for
the
AK
-
50
,
-
75
and
-
100
breaker mecha
-
nisms
.
FIELD
DISCHARGE
CONTACTS
DISCHARGE
RESISTOR
1
.
Install
the
safety
pin
(
3
)
as
de
-
scribed
above
.
FIELD
WINDING
mim
AKF
MECHANISM
(
Fig
.
16
)
2
.
Separate
the
front
and
rear
frames
as
described
under
’
’
SEPARA
-
TION
OF FRONT
AND
REAR
FRAMES
”
in
the
’ ’
MAINTENANCE
”
section
of
these
instructions
.
Fig
.
75
.
Typica
/
connection
diagram
NOTE
:
When
reassembling
the
mechanism
,
the
adjustments
listed below
should
be checked
at
the
appropriate
time
of
re
-
assembly
.
The
appropriate
time
for
each
adjustment
is
in
-
dicated
in
the
adjustment
text
.
The
Type
AKF
breakers
are
two
-
pole
breakers with field
discharge
contacts
placed
in
the
center
pole
.
When
this breaker
is
opened
,
the field
discharge
contacts
close
,
thus
con
-
necting
an
external
discharge
resistor
across
the field
of
the
generator
or
motor
.
When
the breaker
is
closed
,
the field
discharge
contacts
are
opened
.
See
Fig
.
15
for
a
typical
circuit
con
-
nection
.
3
.
Remove
the
closing
spring
as
-
sembly
by
removing
the
upper
and
lower
spring
pins
(
1
,
31
)
.
4
.
Remove
the
right
hand
bearing
side
plate
(
20
)
,
and
the
side
plate
shims
(
18
)
if
present
,
by
removing
four
mount
-
ing
bolts
(
19
)
,
thus
allowing
the
main
closing
crank
(
25
)
to
be
removed
.
Adjustments
(
Fig
.
14
)
Frequent
adjustments
to
the
mech
-
anism should
not
be
required
.
If
the
mechanism
has been
disassembled
,
it
will
be
necessary
to
check the
follow
-
ing
adjustments
:
When
the
breaker
is
tripped
,
the
opening
springs
pull
crossbar
(
9
)
down
-
ward
,
opening
the breaker
'
s
outer
poles
.
As
the
crossbar
moves
down
-
ward
,
link
(
A
)
rotates
about
a
fixed
center
(
17
)
,
collapsing
toggle
links
(
B
)
and
(
C
)
upward
,
thereby closing
cen
-
ter
-
pole
contacts
through
connecting
link
(
D
)
.
Link
(
C
)
consists
of
two
links
riveted
together
,
forming
a
single
tri
-
angular
link
.
5
.
Remove
the
closing
handle
(
22
)
by
removing
two
set
screws
threaded
in
same
hole
.
1
.
It
may
be
necessary
to
add shims
(
13
)
to
reduce the
end
play
of
the
rat
-
chet
wheel
shaft
(
16
)
.
An
end
play
of
0.010
to
0.020
of
an
inch
is
recom
-
mended
.
Shims
should
be
obtained
from
the
factory
.
6
.
Remove
the
front
escutcheon
by
removing
four
screws
holding
it
to
the
front frame
center
support
.
7
.
Remove
the handle
return
spring
(
29
)
by unhooking
either end
of
the
spring
.
2
.
It
may
be
necessary
to
add
buf
-
fer
stop
shims
(
27
)
to
the buffer
stop
(
26
)
to
provide
a
clearance
of
1
/
64
to
1
/
32
inch between the
pawls
(
21
)
and
the buffer
stop
,
when the
pawls
are
touching
the ratchet wheel teeth
ex
-
tending
a
maximum
distance
from
the
center
of
rotation
of
the ratchet
wheel
(
17
)
.
This
measurement
should be
made while
operating
the
closing
han
-
dle
during
the
four
spring
charging
op
-
erations
and
before
the
closing
springs
are
reassembled
.
Contact
Adjustments
8
.
Disconnect the
top
end
of
each
pawl
spring
(
7
)
.
Maaturamanft
For
contact
measurements
and
ad
-
justments
of
the
two
outside
poles
of
the
breaker
,
refer
to
POLE
UNIT
ASSEMBLY
.
9
.
Remove
the roll
pin
(
24
)
,
thus
allowing
the
closing
handle
shaft
(
23
)
and
pawl
assembly
(
23
)
to
be removed
.
10
.
Remove
the
ratchet wheel
(
17
)
and
its
assembly
(
16
)
by
removing
Nylok
*
screw
(
15
)
and thrust bearing
(
12
)
.
If
shims
(
13
)
are
present
they
must
also be
removed
.
Contact
measurements
of
the
cen
-
ter
-
pole
field
discharge
contacts
should
be made
on
the left
contact
and be with
-
in
the
following
limits
:
3
.
The ratchet
pawls
(
21
)
should
op
-
erate
freely
throughout
the
closing
strokes
.
They
should
engage
the
rat
-
chet
wheel
teeth
near
the end
of
each
counterclockwise
and clockwise stroke
of
the
closing
handle
with
a
definite
clicking
sound
,
indicating
a
free
non
-
binding
operation
.
After
the
clicking
sound
is
detected
,
the
closing
handle
should have
a
minimum overtravel
of
1
/
2
in
.
or
3
1
/
2
degrees
,
measured
at
the
end
of
each handle
stroke
.
1
.
Contact
wipe
,
3
/
16
in
.
to
7
/
16
11
.
Re
move
front
bearing
plate
(
9
)
by
removing
three
mounting
bolts
(
10
)
ac
-
cessible
from
the
front of
the breaker
.
The
mechanism
is
now
completely
dis
-
assembled
.
It
is
not
recommended
that
any
of
the
subassemblies
removed dur
-
ing
the
above
operation
be further
dis
-
assembled
in
the
field
.
Replacement
sub
-
assemblies
should
be
obtained
from
the
factory
.
in
.
2
.
Contact
pressure
,
101
b
.
to
16
lb
.
3
.
Gap
between
contacts
when
cen
-
ter
pole
is
open
,
11
/
2
in
.
to
1
3
/
4
in
.
4
.
Overlap
between the
center
-
pole
contacts
and the
arcing
contacts
of
the
outer
poles
,
3
/
16
in
.
to
7
/
16
in
.
12
.
To
reassemble the
mechanism
,
reverse
the
procedure
described
above
.
4
.
The
groove
pin
(
14
)
in
the
front
of
the
ratchet wheel
assembly
(
16
)
must
be assembled
in
a
manner
that
will
al
-
low
Nylok
screw
(
15
)
to
be
tightened
Measurements
of
the
center
-
pole
contact
wipe
and
pressure
may
be
made
by
following
the
same
procedure
as
outlined
for
the standard
pole
unit
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