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PRACTICES
BELL SYSTEM
PlantSeries
AT&TCoStandard
AND BEttS
BUZZERS
A ND L I ' NI T A T I O NS
C ON N E CT I O NS
I.
GEIIERAL
l.0l
This sectlon covers the connectlons for
buzzers and bells and provides a standard
method of connecting pushbutton and buzzer
systems.
1.02 It is reissued to modify Fig. 2.
2,
2.02 Relay equipment may be used to operate a
number of audible signals in multiple. Do
not exceed maxlmum load of relay contacts.
2.03 Buzzers or bells should be of thesametype
throughout a pushbutton and buzzer system.
20124or KS-16184
Transformer
LIM|TATtol{s
2.01 The number of audible signals operated in
multiple by a common pushbuttonor 6021type key shall not exceed:
2.04 Etther a 2OI2A or KS-16[84 transformer
may be used for small pushbuttonand
buzzer systems requlring not more than 1/4 amp.
2.05 Wtth 115 volts 60 cycles applied to the
primary, the secondary winding delivers
6.7 volts 60 cycles at 0.250 amp.
.
Nine 74-49 bells.
a
Ten 74-49 buzzers.
.
Six 7E-49 bells.
o
Eight 7E-49 buzzers.
2.06 Where a common battery feeder is usedfor
intercommunicating and signaling, connect
a 234 KTU across rhe slgnal circuit (Fig. 1).
Filler
Fig. | - lloaseSuPPressaon
@ American Tclephone and Telcgraph Company, 196{
Printed in U. S. A.
PageI
sEGTt0t50r-r20-f00
ST AT ION WOR K S H E E T D IA GR A M
D
Z - BU Z Z ER O R BELL
S _PU SH SU T T O N KEY
GR D- GR O U N O
BAT,- BATTERY
s
s
s
z
PLACE STRAPS TO
OBTAIN SlctrlALla{G
ARRANGETIEiIT
R E OU IRE O
I
T_
I
-tI
Note 1: Ground leads shapped common.
Note 2: Battery leads strapped common.
Note 3: All leads are paired.
fi
-t
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T
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ll
GR D
s
GR D
s
GR O
s
GRO
I
rc
j
SU Z Z ER
OR
BELL
and BuzzerSystem
Fig. 2 - Lalge Pushb||llon
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2.01 Table A glves the maximum wire length
berweenpushbuttonkey and buzzer orbells.
Signals are operated ln muldple.
TABLE A
MAXIMUM
WIRELEIIGTH
llumberot
lB-49Buzzers
or 7G-49
Bells
3.03 Pairlng of all leads wtll reduce the posslbility of interference in adJacenttalklng
clrcults.
Lengfhof Bun
for OnePair of JKT Wire
feet
0- 1 1 0
Ilt- 6 0 0
601-1
100
2
I
3.02 Subsequentchanges and additlons may be
made with a minlmum of wiring changes.
3.04 Where 7-type bells are connectedto 60cycle alternating current, bell operatlon
may be more satisfactory lf the dc termlnals
are used.
3.05 Connect 7-type buzzets or bells as shown
in Fig. 4.
3.
G oililE oTtolts
3.01 A simpltfled method of connectlngbuzzers,
bells, and pushbutton keys is to be used on
all systems. This method ensures the pairing of
all key and buzzer leads throughout the system
(Fig. 2 and 3).
l-corutnrI
3.06 Where radlo frequency induction is caused
by a sparkingbuzzer or bell contact, operatlng power should be ac and connectlons should
be to the ac terminals. A l52A capaciror should
be used across buzzer contactswhenpower supply
is dc (Ftg. 4).
7 - T Y P E B U Z Z E RO R B E L L
a L o cK I
AC C ON N EC T IO N
Fig. 3 : SmallPushDrnon
andBuzzerSystem
Fig.0 - ACandDCConnections
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3 Pages