GE AKR-30 Series Maintenance Manual page 204

SECTION 7 -Breaker Maintenance (Cont.)
3. Check resis t ance of the disconnected undervoltage
device. See Table 5 for values.
See i nstruction Sheet G EH-4545 for more detai led infor­
mation, including schematic diagrams and circuit descrip­
tion.
The undervoltage device must be cal i brated through the
time-delay unit after the device pick up has been adjusted.
A .008 inch minimum closed gap must exist between the ar­
mature and magnet as shown i n Fig. 32C. Refer to Section
7.8.3 and Table 24.
7.1 0 ELECTRIC LOCKOUT DEVICE
The electric lockout device uti lizes an undervoltage
device to keep the breaker from resetting its mechanism if
the breaker is open and the undervoltage device coi l is not
energized. The breaker thus cannot be closed unless
voltage is on the. coil. 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
33.
the device. See Fig.
means of electrically i nterlocking two breakers so that they
cannot be closed at the same time. Each undervoltage coil
may be wired in series with a "B" aux i l iary switch contact
on the other breaker for cross-interlock purposes.
On each breaker having an electric lockout, an arrange­
ment is made which al low breaker closing with the coi l
will
de-energized. Th is is provided to al low "start-up': o n "dead"
34
systems. Figure shows this device. The push sl ide
shown is located in the opening in the lower part of the
escutcheon. This breaker door must be opened to gain
access to it.
: � / -
. / lL ' i
I
:
.'
r
-
FIG. 34 ELECTRIC LOCKOUT BY-PASS
26
This arrangement provides a
MAI N SHAFT
( BREAKER CLOSED)
� �/
'
\
-
�
.
"--' ___) :
·-�
- -
HOLD- IN
· ---._
L I NK
11· 1
-
FIG. 33 ELECTRIC LOCKOUT DEVICE
7.1 1
BELL ALARM
This device is used to give a remote indication of the
breaker having tripped open through the action
its automatic protective devices. It will no t be ac t ivated by
manual tripping or the action of the shunt trip. A remotely
mounted protective relay energizing the shunt trip wi l l there­
fore not result in the remote alarm action.
The bel l alarm circuit may be turned off by pushi ng in the
manual trip or by energizing the shunt tri p. In the l atter case,
a normal ly open contact of the bel l alarm switch must be
wired in paral lel with the "A" auxiliary switch contact i n the
shunt-trip circuit. Closing the breaker will also turn off the
alarm.
The bel l alarm device may be equipped with a lockout
link which will lock the breaker open until the bel l alarm
device is reset.
The bel l alarm is not a standard device and is suppl ied
only when specified on the breaker order.
7.1 1 .1 OPERATION
35:
Referring to Fig. the bel l alarm mechanism is ac­
tivated by a crank which is assembled to the breaker's
shaft. When the breaker opens, a pin attached to this crank
moves the alarm link against the switch and locklever (if
provided). Thi s activates the switch contacts. It also moves
the locklever adjustment screw against the trip shaft paddle
keeping the breaker trip free .
LATCH ENGAGEMENT
POINT
-
FIG. 35 BELL ALARM DETAILS
1
of one of
mai n