GE AK-50 Series - Page 20

GEK
-
7303
Low
Voltage
Power
Circuit
Breakers
T
1
.
Springs
2
.
Insulation
3
.
Stationary
Contact
4
.
Pin
5
.
Screw
6
.
Movable
Contact
7
.
Pin
8
.
Buffer
9
.
Crossbar
10
.
Adjusting
Plate
11
.
Bolt
12
.
Buffer
13
.
Screw
14
.
Shims
15
.
Bolt
16
.
Pin
17
.
Pin
17
—
16
15
Fig
.
17
(
227
D
174
)
Field
discharge
contacts
(
center
pole
)
and
pressure
may
be
made
by
following
the
same
procedure
as
outlined
for
the
standard
pole
unit
in
POLE
UNIT
ASSEMBLY
.
Overlap
of
the
center
-
pole
contacts
and
the
outer
pole
arcing
contacts
may
be
checked
by
the
following
procedure
:
Remove
arc
quenchers
(
see
ARC
QUEN
-
t
When
the
breaker
is
tripped
,
the
opening
springs
pull
crossbar
(
9
)
downward
,
opening
the
breaker
'
s
outer
poles
.
As
the
crossbar
moves
downward
,
link
(
A
)
rotates
about
a
fixed
center
(
17
)
,
collapsing
toggle
links
(
B
)
and
(
C
)
upward
,
therby
closing
center
-
pole
contacts
through
connecting
link
(
D
)
.
Link
(
C
)
consists
of
two
links
riveted
together
,
forming
a
single
triangular
link
.
1
.
CHER
)
.
2
.
Insert
safety
pin
in
push
rod
.
(
See
Fig
.
3
under
MAINTENANCE
.
)
Contact
Adjustments
Measurements
3
.
Operate
closing
mechanism
with
mainten
-
ance
handle
until
arcing
contacts
of
outer
poles
just
touch
.
4
.
Measure
distance
between
forward
edge
of
left
stationary
contact
of
center
pole
and
surface
of
insulation
block
behind
contact
.
For
contact
measurements
and
adjustments
of
the
two
outside
poles
of
the
breaker
,
refer
to
POLE
UNIT
ASSEMBLY
.
Contact
measurements
of
the
center
-
pole
field
discharge
contacts
should
be
made
on
the
left
contact
and
be
within
the
following
limits
:
1
.
Contact
wipe
,
3
/
16
in
.
to
7
/
16
in
.
2
.
Contact
pressure
,
10
lb
.
to
16
lb
.
3
.
Gap
between
contacts
when
center
pole
is
open
,
1
1
/
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
.
Measurements
of
the
center
-
pole
contact
wipe
5
.
Continue
to
operate
maintenance
closing
handle
until
center
-
pole
contact
opens
fully
.
6
.
Repeat
measurement
described
in
step
4
.
Difference
between
measurements
indicates
amount
of
overlap
.
Adjusting
Center
-
pole
Contact
Wipe
and
Overlap
(
Fig
.
17
)
If
measurements
reveal
either
incorrect
center
-
pole
contact
wipe
or
incorrect
overlap
of
contacts
,
adjustments
should
be
made
by
the
following
procedure
:
j
20
Courtesy of NationalSwitchgear.com