SECTION 7-Breaker Maintenance (Cont.)
3.
Check resistance of the disconnected undervoltage
device.
See
T
ab
le
5
for values.
See
instruction Sheet
GEH-4545
for more detailed infor
mation, including schematic diagrams and circuit descrip
tion.
The undervoltage device must be calibrated through the
time-delay unit after the device pick up has been adjusted.
A
.008
inch minimum closed g
aiJ
must exist between the ar
mature and magnet as shown in Fig.
32C.
Refer to Section
7 .8.3
and Table
24.
7.1 0
ELECTRIC LOCKOUT DEVICE
The electric lockout device utilizes an undervoltage
device to keep the breaker from resetting its mechanism if
the breaker is open and the undervoltage device coil is not
energized. The breaker thus cannot be closed unless
voltage is on the coli. Once the breaker is closed, loss of
voltage will not trip the breaker because, in the closed posi
tion, a mechanical link is used to hold down the armature of
the device.
See
Fig.
33.
This arrangement provides a
means of electrically interlocking two breakers so that they
cannot be closed at the same time. Each undervoltage coil
may be wired in series with a
"B"
auxiliary switch contact
on the other breaker for cross-interlock purposes.
On each breaker having an electric lockout, an
arran
ge
ment is made which
will
allow breaker closing with the coil
de-energized. This is provided to allow "start-up" on "dead"
systems. Figure
34
shows this device. The push slide
shown is located in the opening in the lower part of the
escutcheon. This breaker door must be opened to gain
access to it.
MAIN
SHAFT
'
CLOSED)
l I
:,.�
-
_}.
,
.
'
/Ti
""'·.
'
·"-�
·
� .
.
"""
I
I
.
�
I
HOLD- IN
. .
I
FIG.
34 -
ELECTRIC LOCKOUT
BY-PASS
26
FIG.
33 -
ELECTRIC LOCKOUT DEVICE
7.11
BELL ALARM
This device is used to give a remote indication of the
breaker's having tripped open through the action of one of
Its automatic protective devices. It will not be activated by
manual tripping or the action of the shunt trip.
A
remotely
mounted protective relay energizing the shunt trip will there
fore not result in the remote alarm action.
The bell alarm circuit may be turned off by pushing in the
manual trip or by energizing the shunt trip. In the latter
case,
a normally open contact of the bell alarm switch must be
wired in parallel with the
"A"
auxiliary switch contact in the
shunt-trip circuit Closing the breaker will also tum off the
alarm.
The bell alarm device may be equipped with a lockout
link which will lock the breaker open until the bell alam
device is reset.
The bell alarm is not a standard device and is supplied
only when specified on the breaker order.
7.1 1 .1
OPERATION
Referring to Rg.
35:
the bell alarm mechanism Is ac
tivated by a crank which is assembled to the breaker's main
shaft. When the breaker opens, a pin attached to this crank
moves the alarm link against the switch
and
locklever Of
provided). This activates the switch contacts. It also
moves
the locklever adjustment screw against the trip shaft paddle
keeping the breaker trip free.
,40
�
POINT
./
FIG.
35 -
BELL ALARM DETAILS
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