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Power Circuit Breokers,
GEK-731O
Adiustment (Fig.25)
For
proper
electrical
operation, the
F
and
G
mechanically operated switches must-operate at the
proper point in
ttre
closing
cycle.
If
these switches
are
to be
replaced,
measure
the
distance between the
tip
of
the
switch button
and
the
bracket on which thev
are
mounted.
When
the
new switch
is
mounted'.
duplicate the measured dimension. then check
for
proper operation.
When
a
normal closing
operation
occurs,
the
ratchet usuatly comes to a
stop
with an arbitrarily
designated
ratchet tooth
No.
1,
Fig.
28,
engaged
by the holding
pawl.
This
tooth
is the
one wtrictr is
in
line
with an imaginary line
passing through
the
centers of
the
camshaft (2) and the
rivet
opposite
the
roller
on
the
ratchet assembly.
It is
matter of
no
concern
if
the
action stops
on
a
different
tooth.
but
it
is
important to positively identify tooth
No.
i
by the method described.
To check
the switchaction,
a-fter
tooth
No.
t
has
been
identified, turn tfie
camshaft
with the
mainte_
nance
handle and count the
teetl
as
they pass the
holding
pawl.
By using a
continuitytester, bbserve
whenthe switchesoperate as
the
raichet
turns.
The
normally
open
F
switch on
the left
will
close,
and
the
G
switch
will
open.
Electrical breakers
should
operate
the switches
while moving from tooth
No.
101o
toottr
No.
11.
If
this check
shows
that anadjustment
is
needed,
the switch to be corrected can be
moved
closer
to
or farther
away
from
the paddle which operates t}le
switches. A very thin
open-ena
b/g-inch
wrench
will
be
needed
to
loosen
or
tighten
the nuts which
fasten
the switches to the bracket.
BErr
ArARtYl/LocKouT
(FtG. 26)
In
Fig.
26, the bell alarm
device
is
shown
with
its
components
in the positions they
will
be
in with
the
breaker
closed.
Fixed
centers
in tne mechanism
are
shaded
solidly;
center
s
which
are
cross
_hatched
are fixed only in the reset position.
When
tlre
breaker opens, tlre crank pin
(1),
Fig.
26,
pushes against
the alarm link
(2)
wti"n
ctos&
against the
bellalarm
switchbuttons
(3). If
a
lock_
out-link (4)
is
provided,
this is
pushed'by
the
same
actionand causestfie endof ttre adjustment screw to
act against
the
trip
shaft
paddtb
(b) teeping
tlre
breaker from closing until ttre mechanism
is
reset.
-
Resetting
is
done.,either
by
pushing on the
trip
button (9)
orbyoperatingthe
strunt
trip
[tZ;.
Eithei
action causes the latching edges
of
-tie
two
latch
links
(6)
and
(7)
to separale. A slide
attachment
on
the
trip
sha.ft
or the
second
Elrm
on t}te
shunt
trip
armature, both
indicated by
(g),
push
latch link
(?)
away
from
latch link
(6).
This releases the switcir
buttons
and
the lockout
link,
if
there
is one.
The
breaker closing
motion puts tlre
latching links
back
into position to be re-engaged
If
the
shunt
trip is
to
be used
for
resetting,
a
normally
open
bell alarm
switch contact
musf
'be
ivirgd
in
parallel
with the
auxiliary
switch contact
in t}te.breaker
trip circuit.
If
t}te device consists only
of
a bell alarm,
re-
setting
is
also
accomplished
by
closing tfie breaker.
.If-
a
breaker
is
equipped
wittr
a
bell alarm
Aock_
out device
originally, all
the adjustments
are
made
at the time of assembly.
Switch
operation
is
con-
trolled by
means
of
shims
of
insulating material
placed between
the
switch
body and the-bracket to
which
it
is fastened.
The adjuslment
screw
is posi-
3
2.
Carnshaft
L Ratchet
Tooth
No.
I
3.
Ratchet
Stop
Roller
Fig.
25.
(0154C2126)
Gearmotor, pautls,
and
ratchet
subassembly
,'6ti\-
l\\rti
_-+=-
.l
..t
i
la^,
'-.w',
l{ao)
tl,/-.'
i\::i/^'
27
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