Western Electric 1A1 User manual

TELEP~HONE
EM
l
I
wesrem Electric

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Copyright, 1955
Westem Electric Company, Incorporated

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I
Table of Contents
General Description ~ ~ ~ ~~ ~~ ~~ ~ ~ ~ ~ ~ ~ ~ ~ ~~ ~ ~ ~~ ~ ~ ~~ ~ ~ ~~ ~ ~ ~~ ~ ~ ~. ~ ~~ ~ ~ ~~ ~ ~ ~~ ~ ~ ~~~~ ~ ~ ~ ~ ~ ~ ~ ~~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~ ~ ~ ~~~ ~~~ ~ ~ ~~~~ ~~ ~~~~~ Page 1
Station Apparatus
Backboard
Bracket
Buzzer
~~~~ ~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -~---~~~~~~~~~~-~
Condenser ~~~~ ~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~
Connecting Blocks ~ ~ ~~~~~~~~~~~~ ~~~
Covers~~~~ ~ ~~-~~~~~~~~~~~~~~
Fuses ~~~ ~~ ~~~~-~~~~~~ ~~~~~~~~~~~
Telephone Sets ~~~~~ ~~~~~~~~-~~~~~~ ~~~~~~~~~~
Cord &Cable Connections~ ~~~~~~~~-~~~~
Common Equipment
19,22
21
26
27
22
~~~~~~~~~~~~~~~~ 18,19,22
~ ~~~~~~~~~ 25
~~~~~~~~~~~~~ 3
22,23
Cabinets ~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~ ~-~~~~~~~-~~~ ~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~
18
14
14
Individual Feature Key Telephone Units~~~~ ~~ ~~ ~ ~~~~
Multi~feature Key Telephone Units ~ ~~~~~~~~~~ ~
Ringing Arrangements ~~~~~~~~~~~~~~~~~~~~~~~~ ~ ~~~~~~~~~~~~~~~~
Power Supply ~ ~~~~~~~~~~~~~~~~~~~~~~~~
Operation
Line Circuits ~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ ~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~
Holding ~~~~~~~~~
Wink ~ ~~~~ ~~~~~~~~~ ~
Intercommunication~
Manual~
Dial ~~~~
Audible Signal ~~ ~ ~~~~~~~~~~~~~~~~~~~~~~~~~-~~~~ ~ ~ ~ ~~~~~~~~ ~
Hypothetical Installations ~~~~~~~ ~~~~~~~~~~~~~~~ ~~~-~- ~~~ ~ ~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~
16,24
24
25
25
26
26
26
26
27
Interconnections Between Units ~~ ~~~~ ~~-~ ~~-~-~~~ ~ ~ ~~ ~ ~ ~~ ~ ~ ~ ~ ~ ~~ ~ ~~~--~~~ ~~ ~ ~ ~ ~~~ ~-~ ~~ ~~~ ~ -~ ~~~~~ ~-~~ ~ ~~ ~~ ~~ ~-~~ ~ ~ ~
31

..
Uleslern Electric
lAl
Key Telephone
System
General Description
The lAl Key Telephone System is a switching sy:;tem designed to provide a method of signaling
cu~tomers stations on one or more lines from a common battery Central Office or PBX without the
assistance of an attendant or operator. The lAl Key Telephone System is a revision of the lA Key
Telephone System incorporating all the features available in the lA System and introducing the wink
and dial intercommunicating features. The cabinet type units of the lA System are replaced by new
cabinet type units with 3 instead of 5 relays per circuit, the relays being of a different type requiring
less mainknance.
The lAl System permits the subscriber to utilize the following features:
a. Answer and originate calls on from one to six central office, PBX, intercommunicating or
private lines.
b.
Hold calls on from one to five central office or PBX Lines.
c.
Answer and originate calls on ringdown tie lines and automatic tie lines between stations
of Key Telephone Systems.
d.
Answer and originate calls on lines to distant individual station telephone sets.
e.
Answer and originate calls on manual or dial intercommunicating lines between stations of
a lAl Key Telephone System.
Any single operating feature described above requires the assignment of one key of the multi·
hutton key telephone sets associated with the lAl System. The multi-button sets have either four or
six buttons and accordingly the features provided with one lAl System are limited to combinations
of either four or less or six or less depending upon the types of telephone sets used.
The combination furnished by a given set may be varied to some extent by making suitable
changes in the connection of the spade tipped leads in the sets as, for example, to convert a pick up
key to a signaling key in those sets arranged for such conversion.
Some codes of telephone sets are equipped with an exclusion key which permits manual cut off
of any other station or group of stations associated with a line appearing at several stations.
Table l on the following page indicates the telephone set codes and feature combinations avail-
ablt• for
USt~ with the lAl System. Circuit Figures l to 4 noted in Table l illustrate the differences in
wirin11: of the various sets. It should be noted as stated in information note 301 that manual sets can
he obtained only by conversion of dial sets.
l

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CIRCUIT NOTE 5:
101. PROVIDE THE KEV TELEPHONE SET IN ACCORDANCE WITH REQUIREMENTS AS INDICATED IN THE
FOLLOWING TABLE- THE CORD CONDUCTOR COLORS ARE SHOWN UNDER THE DESIGNATION Of THE
TERMINALS IN THE SET, EXCEPT WHERE "DO" APPEARS WHICH INDICATES THAT THE SPADE TIP Of
THE CONDUCTOR IS TAPED AND DRESSED UNDER THE TERMINAL PLATE Of THE KEY.
1
I
~- ~-- ------------------------------.--.----------,------------,----~---------~------------~-----------r--------~~----------r~~~"'----.-----------~~~~----------------------
•. FEATURES PROVIDED FOR CODING TO LINE 1 TO LINE 2 TO LINE 3 TO LINE 4 TO LINE 5 TO LINE 6 SIGNALING ST:J~.~N RINGER TO EXCLUDED ~~;o6~ LAMP LEADS
OR SIGNALING OR SIGNALING OR SIGNALING OR SIGNALING CKTS. .AMI" LEADS STATIONS ";,;·,r'
--STATION CONTROL KEY SIGNAL f---~-~-.-----,------,----+--+-.--.-:::BA"'Lc-r:HO-:::L-,D+-.---r--rH-c:O:-L-::Dt--r'-·--1------· HOLD HOLD OLD HOLC
1 l
PI! -:::} ,.
ARRANGEMENT EXCLLAMPSS KT SET CODE CORD KEY RINGTIP OR OR RINGTIP BAL OR RING TrP BAL AOR RING TIP BAL AORRING TIP BALAOR RING TIP AOR SIG.LEADS :R~ BUSY R B RINOJI'-P BALHOLCRI.,TIFLI~E~A:; LI~E LI~E LI:E LI~EL~,
H•HOLD P•PrCKUP S•SIGNAL KEY SEE BUSY I FIG SEE NOTE 301 GOOE CODE AI A A ~- ·~ SIG SIG SIG SIG
pS•CONVERTIBLE PICKUP SIGNAL NOTE LAMP : f--::·-·-- <><~I<,NATION OF TERMINALS ON KEY ANO LAMP TERMINAL STRIPS EXCEPT AS OTHERWIS.£E:-'!S.!.T~A.'.T.£E~D-'---,--,--,--r-,--,--r---r.,.--,--r---,......,-,-~,----,,---j
C•CUTOFF ITURNBUTTON) 310 DIAL .. ANUAL IR IT 18 IH 2R 2Ti DO" 2H 3R 3T l DD" 3H 4R 4T DD" 4H 5R 5T DD" 5H, 6R 6T 6H IS SOR2sj SG L2(0NINO.CL R::~RTHRI ET EB ~E_H_ CR CT 1 LG 2 3 4 5 6
~--P~-Po_Po 1 1 s4iisilw s4oBAW DI4D 3
588
A R G v BK BL w·eR-R BR·GBR·YBR:_eKj_BR·BLBR-w Y·BLY-wf-- .. -· -----~---+--+-+-----4--1-----+-+--+-+----1
e-----..;==-~====----+--1---+--+ -4----+---+-----'r-------~- - f--- -t ~· --- -t- -- t ~ -- -c-- - -
~-~~====~=~~-~-~-JT+--~-2~~s~~~s~s~w~s~~~B~A~w*---J.-~D~I~~~-~3~.---+-hR~~G~~Y~t~a~K~~B~L~~w~e~R~-~R~B~R~~~~~~~~~BLB~w G~ ~BL~w-- 1 --~--e-- s~ ~BK s~L ~w
Ho Po PoPO
1
f----t--.!....-+----+--+--"--+---+---~------' 5eee \
i-----~G=cp~O~P"'o"'·=Po"'2!n"=Po"'s~---!---.f.---J 3 s~;:B~ ~~4A~t ~~_ll~~~3j~~BBC R G ~ :~ :~C..~~~~~ ~~~;~~R-BK~~:R~W R-G R=~~ R-BL ____ -_-- f---+- __ ~~ ~~ ~=~-=- !;~y:: =·1·~ _ -- --c---~;~-KJ--S---BL+S---w+s---6-R+-f----i
__ IH() Po Po Po Po Po I 1---f---r-r---~=- I 564BB\I;Is648A'wl---- '__o2B_A_::i:~
8
_
9
__ A __ +--+f--"R'--+_G,+Y BK _B_l,_ 'II BR--R~~~ sii:YeR·BK BR:el."BFM¥~-~:'(_~BK ~:BL R-w G:Y~e'K"G-BLC..--t-- :~ 1-- -+--- --- ---- Y~Bl~~ --- f--_:::__1--f---- s-vfs::'sK~_:_BL,_ii:-_w S-BR BR
f-~~"'H=io~P=iO."=P~Oi==P~Oi==P~0~
5
~0~~'-i--1f-~J+---·-_- _- ++- _- r_l-·-1o-5-5':64"_lC:tJBV\.W'f5'!'6:::4C"'-A'.":W+--- t---~~5_A- __ 3 ___ t--_
58
_9 _0
_-+----l-R-t-_G--t- __ Y-t !lK __ B'= W BR R ,!!f!.:G BR·Y BR·BK BR--BL BR-W R-G R·Y R-BK R·BL _____ 1---- ____ ___ e-- _ - -G: BL ~ -~--- ~BL y;,v -j - - - . _ S-Y S·BK S-BL S·W+S'-·_,_B_R+-------4-~
[ H0 P0 P0 P0 s0 s0 I v 1 s64Dow s64DAw D25A· 3 5B9 e: R G v BK aL w eR-R eR-G sR-Y eR BK BR-BL sR-w~ ~ ~ t R·BL G·BL iG-w Y-llL v-w ~ s-Y s-eK s-BL s-w ~
f.-~~;;P;;o;;;P;:O;;;p;:O;;;P;:b;;;P;'6;;;;:P;';6~1--i-.j__;f---.j~+-.j--+-3-f-5-6-5A_BV:: 565AAW D34A-3 589C R G . Y BK BL W BR·G BR·Y BR-6K BR·W R·G R·Y R·Bl R·W G·Y G·Bl G·W Y·BK R·13K C·BK BR·BL Y·BL Y-'N~K-13L BK·W BL·W S ~- Y S·BK S·BL S·W S·BR BR BR·F
[ Ho Po Po P6 P6 P~ j v .; v 2 s6sssw s6sBAw --t--D-3_4_A_·_3-+_!5_B_9_a __ +---+-R---t-G-+--' , " , " w " ~';;;:; "'""' ":""_.,' ,,' ,:;, ',_;~ ,. ,:;-~, •-oc C-- ·1l• ,_,, '," .~: l"'~ ' ,_, ~ '~" ':_• ,'~'-R+e ___ R+---1
~-'-H_o_P_O_p_O_p_O_p_~ __ C~-~-.j-~-.j+-.J-
41
-4-~5-6-5E_B_W"·5~6-5~E-A~W-:I-----~·-~D~3~-I-A~-~3-:~-5-8_9_F--:--:~R-.·G~:-- __ -Y_-."B_K_~C-B-Li•-W~j-B-R~---R·LB~R-·-·GLB~R-·~~~,.W~4- •• •oc ~~ ~: __ ~-·~ ':"_~-~-~··~~,--~-~- ~·~-
c=:::) A CIRCLE AROUND A COLOR ABOVf INDICATES A CORD CONDUCTOR • DO INDICATES CONDUCTORS THAT ARE TAPED
L------------'--L..-....L __ __L _ _L __ J._ __ ....L __ __r ____ __L ___ _J._j____.! ____ W_H_IC_H_IS_N_O_T_R_cE_O_U_IR_E_D_F_O_R_U_S E IN THIS SET, AND STORED UNDER THE TERMINAL PLATE OF THE KEY
________________________ _J
INFORMATION NOTES:
310. FOR MANUAL SERVICE REPLACE THE DIAL OF THE CORRE-
SPONDING DIAL
SET (E.G.-540BB) WITH A 958 APPARATUS
BLANK AND TRANSFER THE GREEN KEY LEAD FROM TER-
MINAL "F" TO TERMINAL "RR" ON THE NETWORK TO OB-
TAIN THE MANUAL SET (E.G.-540BA).
302. PROVIDE "M" WIRING WHEN THE BUZZER IS TO OPERATE
ON 60 CYCLE AC, AND PROVIDE "N" WIRING WHEN THE
BUZZER IS TO OPERATE ON DC.
303. All CONVERTIBLE KEY POSITIONS ARE ARRANGED IN THE
SHOP AS PICKUP POSITIONS. TO CONVERT A KEY POSITION
FROM
PICKUP (LOCKING) TO SIGNALING (NON-LOCKING).
REMOVE THE SCREW DET All P-12A892 ENTIRELY FROM THE
PLUNGER AT THE KEY POSITION TO BE CONVERTED. MAKE
THE NECESSARY CONNECTION CHANGES AS SHOWN IN
TABLE C OF THE FIGURE INVOLVED. TO RECONVERT A KEY
POSITION TO LOCKING, INSERT A SCREW DETAIL P-12A892.
304. WHEN USING THE ARRANGEMENT FOR A COMMON SIG-
NALING
KEY FOR TWO OR THREE, PRIVATE AND INTERCOM-
MUNICATING
LINES AS PROVIDED FOR IN FIG. 2, THE SIXTH
KEY IS CONVERTED TO NON-LOCKING AND IS USED AS THE
SIGNALING KEY. THE SIGNALING IS DIRECTED TO THE "S"
OR "S I" LEAD OF THE 2nd 3rd OR 4th LINE, AS REQUIRED,
THROUGH THE CROSS CONNECTIONS SHOWN IN TABLE C
FOR FIG. 2. THE AUTOMATIC CUTOFF FEATURE OF THE IAI
KEY TELEPHONE SYSTEM CANNOT BE USED ON A LINE CON-
NECTED TO THE COMMON SIGNALING KEY.
305. TO PROVIDE FOR A STATION BUSY LAMP FOR THOSE SETS
WHERE SPECIFIC PROVISION FOR THIS FEATURE IS MADE
(SEE TABLE NOTE 101} THE NECESSARY CONNECTION
CHANGES SHOULD BE MADE AS SHOWN IN TABLE A OF
THE PROPER CIRCUIT FIGURE. FOR THE IAI KEY TELEPHONE
SYSTEM IT IS NECESSARY, IN ADDITION, TO PROVIDE A IN91
DIODE (G.E. CO. OR EQUIV.) AND A MIW CORD (OR EQUIV-
ALENT) AND CONNECT THEM AS SHOWN IN FIGURE, WITH
THE DIODE CLOSE ENOUGH TO THE TERMINALS TO PRE-
VENT IT TOUCHING THE CAN OF THE 425B NETWORK. SEE
ALSO CIRCUIT DRAWING, SD-69241-0 I, FOR STATION BUSY
SIGNAL.
306. PROVIDE "Y" WIRING FOR METALLIC RETURN. (METALLIC
RETURN SHALL ALWAYS BE PROVIDED WHEN THE BATTERY
IS NOT LOCATED IN THE SAME BLDG. AS THE KEY TELE-
PHONE SYSTEM OR WHEN IT IS LOCATED IN THE SAME
BLDG. AND rT IS CHARGED OVER METALLIC RETURN FEED-
ERS. METALLIC RETURN SHALL ALSO BE USED ON A-C
SUPPLY). PROVIDE "Z" WIRING FOR CABLE SHEATH RETURN
(CABLE SHEATH RETURN SHALL ONLY BE USED WHEN THE
BATTERY IS LOCALLY GROUNDED AND LOCATED IN THE
SAME BLDG. AS KEY TELEPHONE SYSTEM.)
30i. SETS EQUIPPED WITH CUTOFF KEY PER FIGURE 4 ARE WIRED
IN THE SHOP WITH THE G-W AND R-W LEADS FROM THE
CUTOFF KEY CONNECTED TO TERMINALS "2T" AND "2R"
RESPECTIVELY. AS SHOWN IN TABLE B FOR THIS FIGURE,
THESE LEADS MAY BE CONNECTED BY THE INSTALLER TO
OTHER "R" AND 'T' TERMINALS TO CUT OFF EXTENSION
STATIONS ON LINES OTHER THAN 2. WITH THE IAI KEY
TELEPHONE SYSTEM THE "A" LEAD SHOWN IN FIG. 4 CON-
NECTING TO THE EXTERNAL CONNECTING BLOCK FOR
LINE 2 MUST ALSO BE CONNECTED TO THE CORRESPOND-
ING
LINE.
30L THE RINGER SHOULD BE CONNECTED WITHOUT CON-
DENSER FOR PRIVATE LINE, COMMON OR INTERCOMMUNI-
CATING
LINE SIGNALS EXCEPT WHERE LOCAL INSTRUC-
TIONS
DIRECT OTHERWISE.
30~. THE "R" AND "RR" TERMINALS IN THE TABLES A & BOF EACH
FIGURE ARE ON THE TERMINAL STRIP UNLESS OTHERWISE
SPECIFIED.
31 1'. THE LAMPS ARE NOT REGULARLY FURNISHED AS PART OF
THE CODED SET.
31 I. BLOCKING RING P12A858 CAN BE USED TO MAKE A HOLD,
PICKUP OR SIGNAL KEY INOPERATIVE.
CONNECTION
OF I N91 DIODE FOR USE
WITH STATION BUSY LAMP
IAI KEY TEL, SYSTEM
4258
NETWORK
SEE NOTE 30~
TOTERM.NORM
SEE TABLE A OF
FIGUPE INVOLVED
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TO
SWITCH
*CONNECTIONS PROVIDED
WITH SPADE TIPS
TABLE
3

•
TO LINE AND SIGNALING CIRCUITS DR
TO EXCLUSION K!YS OR CUTOFF KEYS AT OTHER STATIONS
TO LINE &SIG CKT. TO LINE AND
( AUO. SIG. CONTROL l.EAI)g SIGNALING C KT
TO 2ND LINl TO 5TH LINE TO LINE AND SIGNALING CKT.
TO 1ST LINE
TO 3RD LINE TO 4TH LINE
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SEE NOTE 302
RINGER
TERMINAL STRIP
ON KEY ,@,
A
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1SSEr.ABLY
NO
l(~h ' ON 44A BRACKET
TI
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SEE NOTE 301
w
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NORMAL
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DIAL
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PUL~r/
CIA
HAND SET
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425 B NETWORK
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PROVIDED ONLY AS
SHOWN IN NOTE 101
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1ST PICKUP KEY
2ND
3RD PICKUP KEY 4TH PICKUP
KEY
5TH PICKUP
KEY
ONE
TWO
!
SIGNALING SIGNALING
( ( !
KEY
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CORD CONDUCTORS
TO LINE AND SIGNALII CKT OR TO LAMP LEADS IN OTHER
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CORD CONDUCTORS
THESE LEADS ARE TAPED
AND STORED UNDER
TERMINAL STRIPS
TABLE A OF FIG.I
IA-IAI SYSTEM CONVERSION CONNECTIONS OF KEY
AND SWitCH LEADS (SEE NOTE 309)
KEY AND SWITCH LEAD.
KEY TEL SYSTEM
S-W S-G S-Y
y
Y- BK
lA
IB IB N R
IAI
IB
N R M N
TABLE B OF FIG.!
RINGER CONNECTION (SEE NOTE 309)
RINGER OR
BUZZER LEADS
S-R S BK R
SET RINGER USED AS LINE
RINGER ON ANY LINE
SET RINGER USED
AS
PRIVATE LINE RINGER
WITH
OR SET
RINGER
OR
CONDENSER
BUZZER USED
FOR A
COMMON
SIGNAL OR
WITHOUT
OTHER USE (5'EE NOTE
308)
CONDENSER
** T OR R
LEAD
OF LINE INVOLVED
A
A K
RT RR
A A
RT RR
* INDICATES CONNECTIONS INSIDE SET PROVIDED WITH SPADE
TIPS.
FIGURE l
Key and Telephone Circuit
Arranged for Pickup, Holding, Lamps and Signaling
No Convertible Keys
5

•
•
PU
7 D DIAL
SEE NOTE ~01
w
w
G
l
* RR
r-1--1----Jijlf\, y,...-+
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*
61A HANDSET J R
(~_nr7~B~K---------------------r--------~
~
~
-~
S·R f
TO STATION BUSY
LAMP CIRCUIT
~
---------
---------
- ---------- -
TO EXCLUDED
STATIONS
EXCLUSION KEY
PROVIDED ONLY
AS SHOWN IN
NOTE 101
BR-R
~I
HOLD
TO LINE AND SIGNALING CIRCUITS OR TOE XCLUSION KEYS OR CUTOFF KEYS AT OTHER STATIONS (WHEN
(()NNECTEO TO AN I NTERCOMMVNICATI NG Ll NE Cl RCVIT WITH CODE SIGNALING CONNECT THE "S"OR "s1"
LEAD TO THE ASSOCIATED LEAD IN THE INTERCOMMUNICATING CODE SIGNALING CIRCUIT.)
rTO-tST LINE TO 2ND LINE TO 3RD LINE TO 4TH LINE TO 5TH LII;E\
-
I ST PICKUP KEY Z NO PICKUP KEY 3 RD PICKUP KEY 4TH PiCKUP KEY 5TH PICK liP KEY
LAMf"cSTRIP
ON 4
BUTTON
S"TS ONLY
OP SIG KEY OR SIG.KEY OR SIG.KEY
PROVIDED ~N C:NVERTI~=E-E~AB~~ C-A~O NOTE 30\ :J
BUTTON SET ONLY ·7
t--t-~ -----'--. ~ ..... +-------------------+-+--R ~----j
r-t-LG:+-1 -------+-2---- -----4-3------------+-4·-------t-,5
'--tr*-4*~-----+[*-c--------+*--- --·- ----- +*·:-------·f:c*:-'
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TABLE A OF FIG 2
lA -IAlSYs'fEMCONVE RSION ·STATION BUS:CY-"-:Scci::G:-:N--:A-:-L--::-C-::0:-:N-:-Nc:E:-::C-::T:c-10::--::N-::5--,
r----C_ONNECTION OF HOLD KEY AND SWITCH Lf AOS(SEE NOfE 309)
~~[ HOLD KEY a SWITCH-~~~ M IW
SYS. S-W S-G S-Y Y Y·BK C_O_R_D---t---,-o---t
NO STATION lA 18 IB N R M '--
BUSY LAMP IAI IB N R M N
WITH STATION lA SG L2 + N R M
BUSY LAMP IAI IB L2+ R M N G+TONSEENOTE305
!'_T_ER~f<4.1!1AL_()!I~ • .II-£:!WOR~--------------------'
TABLE B OF FIG.2
RINGER AND EXCLUSION KEY CONNECTIONS(SEcNOTE309J
RINGER OR ~X"Ll'~lr···• XEY I
B~fAEOR ,, ~~ t ;, ' . i
S·R S BK R G-·i1fi::-yi~;Y.:v,j:,~
I----;,S-;:E;;T--,-;-Wc;-H:c-E;;-N:::-;U:-:S::-;E::-;Oo;-:;A-;S;-;:;B;:R-;;IO;-;G;:;E;:;D::--t=-f-C--f-il.,
1
.-.!-"lnl~"r--r-~f- --;--
RINGER RINGER ON ANY LINE A K T R I
oR auzuR WHEN us Eo As I WITH ---r --r--
Nor TO BE PRIVATE LINE OR COND. A t<: f
I CUT OFF IN COMMON SI G. 0 R !WITHOUT -t-i RT RR 1
SfT FOSRE~TN~\~~g~ I COND "t;V!AAI I
c------ WHEN USED AS BRIDGED -"* ·-:,.;-;,.:+---t----t
SET RINGER RINGER ON ANY LINE A JK ET ER T R EH EB
~~ ~~l~5~ WHEN USED AS I WITH A K
OFF BY PRIVATE LIN~ OR COND. ET ER RT RR EH EB
EXCLUSION ~g~MOOT~i~\~~~ !WITHOUT A A
~- SEE NOTE 308 I GOND
LINE EXCLUSION
TABLE C OF FIG.2
PICKUP SIGNALING CONVERSION
CONVERT FROM LOCKING TO NON-LOCKING OR VICE-VERSA (SEE NOTE 3031
AND CHANGE L[ADS AS FOLLOWS:
KEY LEADS
NO. OF SIG. NO. OF PRIVATE
KEYS AND INTER-
CONVERTED COMMUNICATING
NO. OF
PICKUP
KEYS
FROMP.U. LINES WITH COMMON Y-BR BR S-BR BK-BR
KEYS SIG. KEY
4 3
BUTTONr-~-1--~---f
SET$ 2 I
5- - MM M X
6
~ 4 I M M M SG_
BUTTON 3 2 - M M SG X
SET 2 3 - M X SG X
4 I 2 M X
5H SG
4 I 3 X X !IH SG
----------·c"'"c-=RD CONDUCTORS _ -· -- -·-- ---~__:_:_:::' __ =:-:::::::--::::-:=· =-==~l=~---'
EXTERNAL CONNECTING~LOCK /1:,_ ~ !1-, !? I *
INDICATES CONNECTIONS IN~IDE SET PROVIDED WITH SPADE TIPS.
t SEE \\_ 1---::- ... -_J; I \'-+-------'/ I \~=--......./_/ I\ I I
~ ~"" ' . .J.tPv.JI' rv/v\ ' _.J_fPv.J~ ""
1
v Tc fv\ fc
t; , ~~ ~ ~fv \V _ ~~\V~- \V ~}
0
2._;~ ~t~~
TO CABLI' \TO 1ST LINE TO ZND LINE TO 3RD LINE TO 4TH LINE ____ TO 5TH I~
SHEAo~ TO LINE AND SIGNALING CIRCUIT OR TO LAMP LEADS IN OTHER SETS,
FIGURE 2
Key and Telephone Circuit
Arranged for Exclusion, Pickup, Holding, Lamps and Signaling
with Individual Signaling Keys or on Private and Intercom-
municating Lines with Common Signaling
Key (See Note 304)
7

•
to
Ll14£ !l TO ,,_ TO EXTENSION RINGER, LISTENING IN
SIG CKT STA TO LINE a SIGNA~ CIRCUITS OR TO EXCLUSION KEYS OR CUTOFF LINE CKT ,CUTOFF STATIOIIS,OR Tl 6 Rl ~ _ TABLE A OF Fl(; 4
(AUO SIG BUSY 1< HYS AT OTHER STATIONS TO LINE 8 SIG CKT (AUX. HOLDING CKT.) r IA-IAI SYSTEM CONV(R'>ION- STATION BUSY-SlG-IIIALCOIIINECTfONS -
c~l~~~l Lt:t T~:'Axr~~~~ED ~ s~~~~~~KT ;-:;:; ISTLINE J.o lN(UINE TO 3RO LINE TO 4TH LINE TOS~~N~K~ ~~c~$~T~~: ~~~ASJ~i6~~~~6~~~~~ CONNECT lOIN OF! HOLD KEY AND SWXtfl::i_LEADS (SEFE NO~OS')
~O:o-,_ "'o: ~ "'_ o- m "':;:r - o: ,_ en :5 ; ~ ~ ~ ~ ~ co cr cr ,_ ro = ;;: "' ::0 ~ ""~,_ I ----~'}, '"" '"'f'P' "'"'" ""'
'· t\' "\1 -·-- -~-----, ::;t ----~-+--+----,·--:;:- < L. _ ·,.-:\ _ L ? ~---,~~- -~ ;:; "\ KT~YL HOLD KEY8tS\IIIfCH LEADS MIW
l/ - - I [; v r ' I; I I;. I; l! ~v I; I;~ ~
0 0
z~ ~T.lTION _If<_ IB JIL rt- R M_ - --
-f----- <r >- ~ r 8USYLAMP IAI 18 111 R M N
p 1- U) w1ht STATION· I_A_ SG- _Lz_• -_-~~~-- R- ,_M
I_ -- - 1-- - --~·- ~------------ tr""----Ex:~::A~o:oo::T~~~c-K--~-'J:.f-----e:=;t::=;t=;t:J-'--l~' • ~~.== ) I -·1---. { -~Q ________ .hr::;U • ~~!~·Ml{P Oil ~:~T~~Il_K_~-· ~-- _::_-----c_N'--=====+-=-~----'
~- I ¥ ;;! ~ ~' j.- -lo>-----lo- <9 >- ~ cr! 3: :.:: .J
_J~ Q)lV~~ ~ ~I I I <!)~aJ!
"'
'
U)
'
U)
! ._:. ;.. ;f; i;; .;: U> cr "' >- m i !I -~ f~f-- _ :;;-+--:lj-4--:;;+ -~+---"'-+--- "'
- ----- - ----- - ---1---~---- -- - -1-------1-- - __ T_H_E_S_E-LEAD_S_A_R_E-TA-P-ED-8--1----+--- '' -+----+-- -1-------· - ------1- f-..-.---
TABLE B OF FIG 4
C4A
RINGER
!700\AL ~-~W A~~ K
SEE NOTE NORMAL•L--~ )B~L=+--*~-<FY'y~--.
301 \~/ ~
OLI
G *
RR
STOREO UNOER TERM STRIP
EXCEPT
AS COVERED IN TABLE *
B FOOT NOTE
1-l--- ,---------------------L·---·-+r·----f--. ;t!, ...... ---+--. I ..
---+--1-----i--------t=*'-----:c·--- ~---------+-----J--#fr -· -----+----l--+----l-+--+----+--+- .. f2'-
1
"----- -- --------+--11-~
,f'_T_ ~~~_li__ EB '": 1! 111 R ~- M 1T IH 2r -+2=-H-f~2_R __ +3_T __ +3_H+3:..R_4 _4_T __ +--4=-H+4_R:.___:.__SG:.___ _____ --------1--x=-T-+- 9X..:.R___,.-c:..T+.::.c:.:JR I
- --~.t:*~··~=~·~~~~f*~~~~·~~~~~~;*~"'*:+f::..J~- ~f: ~f: -="l'~"~~·~~-~·::~:~:K:l=-- :-~~-;!:'_ \ ~-·~~ "~~:~~(.·~;;·-···1\[:~ '• "TL...-lr----1--~
-----f--------- .;,
EXCLUSION
KEY
'-'
'
a:
,..-
d
~
HOLD
0::
"'
(/')~~~
----t--~
1ST PICKUP KEY
-· -----+---+--1---f----+-.......,
'1-· ···--
r--t------
NO PICKUP KEY 3RD. PICKUP KEY 4TH. PICKUP KEY
OR SIG KEY
CONVERTIBLE SEE
TABLE C a NOTE 303
·-
L.
CUTOFF <EY
w ~
l...!!_tt=t.;_r::::::=t:::::::::::!UtJ __ s.-_R ___ ~--~-------------l-Q---'--.]_
SWITCH
c
GN
Vi
II
w
B
*
~ )--,__s_BK --------- -------- ---...J..:Co---.L.U
y
S-BR
I
~t_ ---+-+----- ~.....4-!-------r J I
LAMP STRIP- _ __';~L[G:jl£1 =:t:·-··=::::;~2r:=======:lt~3·;:;;:;~f~l'l
CORO CONOUCTORS -
"' ..J
m >- m
- ------ - ------ - _.;,+-_.,_· 1-- ~---~!----- ---- 0 ----- - -U)+----- - -----
GIA HANOSET
A>
R
II
BK
- ----- - ----- - -----
-----
_j
rl--t------
L--f'r----l--------·11'\-- f/..--j-------fj~p..,-j----------/-~l-----~(
SEE NOTE306l\ !1\\ jJ\ ~
r-(!rJ0I -( ~~0'-+..J ~0--.-JJ~, (,) j3~~'
'- ----'--------~ '---~ !----_:____..:.___; \__~ \.....___C___:____;
TO CABLE ~ST LINE _0 2ND LINE TO 3RD LINE TO 4TH. LiNE;
SHEATH TO LINE IG. CKTS.OR TO L ·~p LEADS 1111 OTHER SETS
EXTERNAL CONN BLOCK
*INDICATE> CONNECTIONS INSIDE SET PROVIDED WITH SPADE TIPS.
[
:--- ~ RtNG(R_,_EXC"i,01QN_- t:<~Y -~CUTOFF ~EY CONNECTIONS(SEENOTE 30
RINGER OR EXCLUSION CUTOFF
BUZZER KEY KEY
f-----,_J,EAD LEADS LEADS
·-·- ____ S-R sfu R G-Y R·Y BK-v.IBR-R G-W R-W
WHEN USED AS :I ... *"
SET BRIDGED RINGER A K T R
RINGER Q.f:I.~~-NO.,ET----+-+-+--+......,1---+-+-+--t--+--1
OR BUZZER WHEN USED WITH A K I
NOT TO BE e,~nkv~~ COND.
CUT OFF
IN ~JG OR FOR Wf:-llcT::-H-:-cOc-U--cT+-----1---4 RT RR
SET OTHER USE I! COND A A
(SEE NOTE
f--.-~-- ~~::;E:-;;D!-A~S:::--+-t-f--if-f--f--+----f-+--1~--l /
SET RINGER BRIOGED RINGER A K I ET ER T** R"" E H EB (
OR BUZZER ~NY LINE
T~N ~~T X"sH~~c-I:V.:.UA-~ST':::EE:CDT---W-IT-H-+-A---4-K+---+-t----f--l--+--+----+-~
EXCLUSION LINE OR COM. COND
KEY SIG OR FOR 1---+---J---4 ET ER RT RR EH EB
OTHER USE WITHOUT A A f
<sE~o~rE coNo I
~----- ~~~~~~-U~S~E~D~A~S~--r--+-+·--r-+---~~--~-+-,.-.+---*--1*
BRIDGED RINGER A K CT CR T R
()J\1 AN'f LINE
WHEN USED AS BOG.
LINE RINGER 11\1
PLACE OF EXTERNAL
6~TB~~~~~ ~fg~~~~N~~REY;_J~~N A **
**
T R
TO BE CUT CUTOFF KEY IS
OFF BY
OPERATED
0
lf!E
0r
X"sH~~~~iH I wiTH 1 A K
LINE OR COM COND
SIG OR FOR 1-----+----+--ICT FR RT RR
OTHER USE WITHOUT I
( SE~O~~TE COND A A
LINE EXCLUSION
OR CUTOFF
EXCLUSION
ON LINE I OR NOT USED =..:..:::...:,.-,1-=T--r~IR~-~~H--r-IB~----r~
EXCLUSION ON OTHER I lA KEY TEL SYSTEM T"" R*" H"*
18
t
THAN LINE 1 I IAI KEY TEL SYSTEM T** R"" H"" EB
CUTOFF ON TIP 8 RING OF ANY LINE
CUTOFF OF HEAD RECEIVER USED AS A
Ll STEN lNG IN SET
* * OF THE LINE INVOLVED
t REMOVE THE YELLOW CORD CONDUCTOR FROM TERMINAL 18 a
TAPE a CONNECT THE BALANCE LEAD CORD CONDUCTOR OF
THE LINE INVOLVED TO TERMINAL 18
t TERMINALS ON NETWORK
rABLE C OF FIG 4
PICKUP-SIGNALING CONVERSION
CONVERT KEY FROM LOCKING TO NON- LOCKING
OR
VICE VERSA (SEE
NOTE 303) a CONNECT S-BR
LEAD AS FOLLOWS.
I CONNECT 5-BR LEAD TO
4 PICKUP
KEYS
"'
3 PICKUP KEYS I SiGNALING
KEY I
SG
FIGURE 4
Arranged
Key and Telephone Circuit
for Cutoff, Exclusion Pickup,
Lamps and Signaling Holding,
1l

Station Apparatus
Key Telephone Sets arc combined telephone sets which include in a single housing the switching
keys, line
and busy lamps if desired, subscriber set apparatus, ringer and the additional cord conduc·
tors required for keys and lamps. Where more than one line terminates in a set the ringer may be
connected to any one of the lines, ringers in adjacent sets or externally mounted ringers being used
for the
balance of the lines. If desired, the set ringers may also be used as an audible signal common
to a group of lines. This feature is described in more detail on page 21 of this bulletin. The keys of
the set serve to switch the talking circuit to any one line. On sets having 4 or 6 button keys the keys
are equipped with a device that prohibits two keys from becoming locked when depressed simul·
taneously.
Common Equipment
When line and signaling equipment for an installation is required it is provided in the form of
Key Telephone Units
(K.T.U.). These are small panel type units approximately 7" high varying in
wtdth
from 2-Y.-:" to 91;.4" wide. Two rows of key telephone units can be mounted in an apparatus
cabinet consisting of a l6A Apparatus Mounting and a ll7A W Cover. The 200DW and 200EW Key
Telephone Units consist of such an apparatus cabinet equipped for 3 or 4 central office or PBX Lines
respectively
in which line, lamp flashing, incoming common signaling and incoming line lamp time out
circuits are assembled and wired. One lamp flashing and time out circuit will provide the requirements
for 5 line circuits when a wink signal is provided or 6 line circuits without wink.
If 6 lines with wink are required an additional 209A Unit must be installed. Other key telephone
units
may be added to the units provided in the 200DW and 200EW Key T~lephone Units depending
upon the operating features desired in a particular installation.
It is sometimes desirable to provide the apparatus cabinet separately to be equipped with indi-
vidual feature units. The following table lists the Key Telephone Units available for use with the
lAl Key Telephone System and indicates the number of each required per line, per station, per group
of lines, etc.
13

INDIVIDUAL FEATURE KEY TELEPHONE UNITS
Feature Reqd.
Fuse Mounting Panel
Central Office or PBX Line Circuit
Automatic Tie Line Circuit
Ringdown Tie Line Circuit
Station Line Circuit
Dial Selective Intercom Line Ckt.
K.T.U.Code
201B
202B
203A
204A
205A
207A
Signal Ckt. for Flashing Line 208A
Lamps
Lamp Flashing & Incoming Signal 209A
Time Out Circuit
Hold Lamp
Wink Ckt. 210A
Cent. Off. or PBX Line Circuit 213A
Manual Intercom Signal Ckt. 3A
Ringing
Lamp Ckt. * llA
Common Audible Signal * l6A
Lamp Resistance Ckt. for D.C. 22 type
Lamp Power Supply
Battery Feed Noise Suppression * 23A
Condenser
Automatic Cut off Circuit 26B
Cut
Through & Control Ckt. for 29A
Automatic
Cut off
lntercomm. Line Battery Feed Ckt. * 31A
# Reqd.
See Desc.
l
Per C.O. or PBX line
l
Per Auto. Tie Line
(see description)
l
Per Ringdown Tie
Line
l
Per Station Line
l
Per 9 Station Inter-
com Line
l
Per 3 Intercom
Stations
l
Per 5 or 6 lines
(see description)
l
Per 5 Lines
l
Per Line
l
Per group for code
signaling
l
Per System
l
Per System
l
Per 2 Lamps per 3
Lines
or 6 Lamps
per line
l
Per Line
l
Per Line
See desc.
l
Per Intercom Line
Panel Size
6H" X 2;i\"
7" X 3fi"
7" x 31/z"
7" X 3f%"
7" X 3fi"
.7" X 5H"
7" X 31/z"
7" X 4ft"
7" x 2o/s"
7" X 4if'
see desc.
see desc;
see desc.
see desc.
see desc.
see desc.
-see desc.
see desc.
* These features included in multifeature 211A Key Tel. Unit noted below.
MULTIFEATURE KEY TELEPHONE UNITS
Comm. Equip. Unit
2llA
l
Per System
7" X 3fi"
3 Cent. Off. or PBX lines with 212A l
Per 3 Lines
7" X 9%"
lamp flashing &time out ckt.
3 Cent. Off.
or PBX lines with 200DW l
Per 3 Lines see desc.
lamp flashing &time
out ckt.
4 Cent. Off.
or PBX lines with 200EW l
Per 4 Lines see desc.
lamp flashing &time out ckt.
14
Description
See Para.
A
B
c
D
E
F
G
H
J
K
L
M
N
p
Q
R
R
s
T
u
v
v

DESCRIPTION OF KEY TELEPHONE UNITS
A. The 201B unit is a single panel fuse mounting for 7 fuses and 6 ground terminals with fuse
terminals wired to an associated terminal panel. This unit is required where battery supply to the key
telephone system is
obtained from a source not always attended by a maintenance man for replace-
ment of fw,es.
Set> paragraph on fusing in POWER SUPPLY section of this bulletin.
B. The 202B is a single panel unit on which the apparatus for one Central Office or PBX Line
circuit is mounted and wired to an associated terminal panel with soldered terminations on the wired
Hide and screw type terminals for connections outside the unit. This unit is used to answer and
originate calls on lines to a Central Office or PBX. A holding feature is provided which permits the
suhRcriher to apply a holding bridge across a line by depressing a hold key associated with the tele-
phone set and to pick up the line again after having obtained desired information or conversed on any
other line associated with the system.
C. The 203A is a single panel unit on which the apparatus for one Automatic Tie Line is mounted
and wired to an associated terminal panel with soldered terminations on the wired side and with screw
type
terminals for connections outside the unit. This unit is used when it is desired to signal auto-
matically and talk on a designated tie line by removing the telephone set handset from its mounting
and depressing the key associated with the tie line. No additional signaling features such as auxiliary
signaling keys or lamps are required. An automatic tie line unit is also required at the distant end of
the line. No hold feature is available with this circuit.
D. The 204A is a single
panel unit on which the apparatus for one ringdown tie line circuit is
mounted and wired to an associated terminal panel with soldered terminations on the wired side and
screw type terminals for connections outside the unit. This unit is used when it is desired to signal
manually and talk on a designated line. Signaling is accomplished by removing the telephone set hand-
set from its mounting, depressing the key associated with the tie line and operating the signaling key
associated with the tie line. The manual signaling feature permits the calling party to make use of code
signaling when more than one station is connected at the distant end. A ringdown tie line circuit is
required at the distant end of the tie line. No hold feature is available with this circuit.
E.
The 205A is a single panel unit on which the apparatus for one Station line circuit is mounted
and wired to an associated panel with soldered terminations on the wired side and screw type terminals
for connections outside the unit. This unit is used when it is desired to signal and talk on a line to a
distant key telephone station. When this unit is used the station at the distant end need only pick up
the Handset and the station at the equipment end is automatically signalled. The station at the equip-
ment end must signal with a button.
F. The 207 A is a single panel unit on which the apparatus for one dial intercomm line having
access to nine stations is mounted and wired to an associated panel with soldered terminations on the
wired side and screw type terminals for connections outside the unit. This unit is used for selectively
dialing nine stations associated with the same intercomm line, any station of the nine being able to
dial any other station. When a station key associated with this circuit is depressed and the handset is
removed from its associated telephone set single digit dialing causes a spurt of ringing of one to three
seconds duration at the called station. No hold feature is available with this circuit.
G. The 208A is a single panel unit on which the apparatus for providing a flashing lamp feature
at three stations of a dial intercomm line is mounted and wired to an associated panel with soldered
terminations on the wired side and screw type terminals for connection outside the unit. This unit is
used to
provide ~ flashing lamp feature at the called station of a dial intercomm line. Without this
flashing feature the lamp at a called station would be lighted steady indicating only that the dial inter-
comm line was in use.
15

H. The 209A is a single panel unit on which the apparatus for the lamp flashing and incoming
signal time out circuit is mounted and wired to an associated terminal panel with soldered termination!!
on the wired side and screw type terminals for connections outside the unit. This unit is used when
flashing
lamps and a time out circuit are desired at the stations of a lAl Key Telephone System, the
flashing lamp indicating an unanswered condition on the line associated with the lamp and the time
out circuit removing all indications of an incoming call on the line if the line is unanswered after
approximately 30 seconds. If a wink signal is used for indicating a held condition this unit can provide
the flashing and time out feature for five lines. Wheu the wink signal is not used the unit provides
flashing and time out for 6 lines. This unit or its equivalent is required for all central office or PBX
Lines.
J. The 2lOA is a single panel unit on which the apparatus for a wink signal feature is mounted
and wired to an associat<.>d terminal panel with soldered terminations on the wired side and screw
type terminals for connection outside the unit. If a wink signal feature is not used a held line appears
the same as a busy line having its line lamp illuminated steady. With the wink feature the lamp of a
hdd line is off three hundredths of a second during each second of operation giving the impression of
a wink. The wink is easily distinguishable from the flashing line lamp signal of an incoming call
which flashes the line lamp off one half second and on one half second during each record of operation.
K. The 213A is a panel type unit on which is mounted the apparatus and wiring for one central
office or PBX Line Circuit for use as a single line common to stations of both lAl and lA Key Tele-
phone systems. Apparatus is wired to associated terminal panels with soldered terminations on the
wired side and screw type terminals for connections outside the unit.
L. The 3A is an angle bracket type unit on which a signaling relay Js mounted and wired to a
terminal panel with soldered terminations on the wired side and screw type terminals for connections
outside the unit. This unit is not designed to mount directly on the l5A or 16A Apparatus Mountings
and when required must be mounted on a bracket, P-37B204, which is arranged for mounting on the
15A or l6A Mounting". The 3A Key Telephone Unit is used when both code signaling and selective
signaling are desired. No auxiliary equipm~nt is required for buzzer signaling when all of the buzzers
are operated either selectively or on a code ringing basis but when some of the signaling keys are used
for selective buzzer operation and others are employed to operate the same buzzers on a code signal-
ing basis. the .3A Key Telephone Unit or its equivalent will he required.
M. The llA is an anglt> bracket type unit on which a resistance lamp is mounted and wired to
a
terminal panel with soldered terminations on the wired side and screw type terminals for connections
outside the unit. The resistance lamp is ust>d to prevent ringing current exceeding safe limits and to
improve the performance of small ringing generators under maximum load. The resistance lamps are
used to insure ringing current to other apparatus working on same supply if ringing grounds or
cro,;ses occur beyond lamps of circuit in trouble. This unit. like the 3A KTU must be mounted on
hinged bracket 37B:204 when it is desired to mnunt the unit on the 1 SA or l6A Apparatus Mountings
with panel type key telephone units.
N. The l6A is an angiP bracket type unit on which the apparatus for an audible signal control
circuit is mounted and wired to a terminal panel with soldered terminations on the wired side and
screw type terminals for conneetions outside the unit. This unit. like the 3A KTC must be mounted on
hinged bracket 37B204 when it is desired to mount the unit on the l5A or l6A Apparatus Mountings
with panel type key telephone units. The audible signal control unit is used when two independent
common audible signals are required with one or more line circuits common to two lines or common
to separate groups of lines.
P. The 22 Type Key Telephone Units are of the angle bracket type with resistances mounted
and wired to a terminal panel with soldered terminations on the wired side and screw type terminals
for connections out-;ide the unit. These units are required when DC power or ·t8 volt batterv over
16

feeders is used to illuminate lamps. The following table indicates the lettered code of 22 type units
that should be used for various conditions:
Type of Battery Supply
FOR SIA LAMPS
Local battery 9 cells l·i-20V
9 Cell building battery l6-22V
10 Cell building battery l8-24V
ll Cell building battery 20-26V
2:::1 Cell regulated cent. off. battery 41.5-SOV
FOR K2 LAMPS
23 Cell regulated cent. off. battery 47 . .'i-SOV
Type of KTU Req'd.
22F
22:G
22H
22J
22K
22]
The~C' units like the 3A 1\:TC must be mounted on bracket P37B204 when it is de~ired to mount
the units on lSA or 16A Apparatus Mountings.
Q. The 2:3A is an angle bracket type unit on which a condenser i,; mounted and wired to a
terminal panel with soldered terminations on the wired side and screw type t<'nninals for connection=-
outside the unit. The condenser is wired across the key telephone sy ,;tt'm battery supply when the
source is poorly filtererl or when noise caused by switching opnations in the system is objectionable.
This unit, like the 3A KTU must be mounted on bracket. P-:nB20-L when it is desired to mount the
unit on 15A or 16A Apparatus Mountings with panel type key telephone units.
R. The 26B and 29A are angle bracket type units on which the relays are mounted and wired
to terminal panels with ~oldered terminations on the wired ~ide and screw type terminals for connec-
tions outside the units. Combinations of the 26B and 29A Key Telephone (Tnits are used to provide
automatic cut off of stations associated with an individual line appearing at several stations. Four
optional arrangements can be provided as follows:
1-A
2--A
3-A
,j, -~-A
station
station
station
station
can cut-off others and can not be cut off.
can cut-off others and can be cut-off except during a call.
or group of stations cannot cut-ofT others and can be cut-off except during a call.
cannot cut-off others and can lw cut-off at any time.
The Key Telephone Units required to provide the ahove conditions are respectively as follows:
1- One 26B Key Tel. l nit per line and one 29A Key Tel. Unit per station
2- One 26B Key Tel. Unit per line and one 29A Key Tel. Gnit per station
3
--One 26B and one 29A Key Tel. Unit per line and one 29A Key Tel. Unit per station or
groups of stations
4 -----!\one --This condition applicable only to one of tlw >'lations that can he cut off in accordance
with condition~ 1. 2. :3. above.
The 26B and 29A Key TC'lephone Units like the 3A KTll must he mounted on a bracke• P-37B204
when it is de;ireJ to mount the units on 15A or 16A Apparatus Mountings with panel type key tele-
phone units.
When th(' automatic cut-off feature is required with a dial intercomm line it is provided by furnish-
ing one 26U Kry Tel. l_lnit per line which in conjunction with a 203A Key Telephone l-nit automati-
cally cuts off all other stations on the line and reconnects only the called station to the calling station.
S. The ::11A is an angle bracket type unit on which a battery feed rela) is mounted and wired to
a terminal pand with ~oldered terminations on the wired side and 5CTew type terminals for connec·
tions outside the unit. Thi~ unit is used to light busy lamps steady at stations on a manual intercomm
line. The 31A KTU like the 3A KTU must be mounted on a bracket P-37B20J 11 hen it j,; desired to
mount the unit on 15A or 16A Apparatus Mountings with panel type units.
17

T. The 211A is a single panel unit on which a pparatus for the manual interc omm signaling ckt,
the common audible signal control circuit, the
rin ging lamp circuit, the batt ery feed noise suppres·
sion circuit and the intercomm battery feed circuit is mounted and wired to an associated terminal
panel with soldered terminations on
the wired side and screw type terminals for connections outside
the unit. This unit provid
es all of the features covered by paragraphs K, M, P and R.
U. The 212A Key Telephone Unit is a single panel unit on which is mounted the apparatus and
wiring for three Ce ntral Offic e or PBX Line circuit s and fla shing and time out circuit apparatus com-
mon to the three lines. This common apparatus will accommodate 5 lines. Apparatu s is wired to
associated terminal
pan els with soldered terminations on the wired side and screw type terminals for
connections outside th e unit.
V. The 200DW and 200EW Key Telephone Units ar e packaged units mounted and wired in a
c
abinet consisting of a l6A Apparatus Mounting and a 117AW Cover with equipment for 3 or 4
Central Office or PBX Lines respectively. The 200DW unit consists of the 212A Unit mounted in a
cabinet.
The 200EW unit consists of the 212A unit plus a ·202B unit mounted in a cabinet. Adequate
s
pa ce is available in the cabinet for units required to complete a key telephone system in .which addi-
tional lines or additional operating features are d es ir ed.
CABINETS AND MOUNTING ARRANGEMENTS
Cabinets per Figure 5 are available for housing the panel type key telephone units of the 200
series. The 200DW and 200EW Key Telephone Units are assembled units mounted and wired in a
c
abinet since it is exp ec ted that a high percentage of lAl Key Telephone System installations will
require one of these basic units. Cabinets consisting of a l6A Apparatus Mtg and a 117AW Cover
are part of the 200DW and 200EW Units or can be o rdered separately when desired.
18
16A Apparatns Mounting on Metal Stand
ED-95023-70 Groups 2 & 4 16A Apparatus Mounting and
117AW Cover
on Metal Stand ED-95023-70 Groups 2 & 4
FIGURE 5

Extension
ED-95023-70 G-6 Foot ED-95023-70 C-2
FIGURE 6
Cover
ED-95023-70 G-4
The assembly of the 16A Apparatus Mounting includes a wood backboard which serves to insulate
the
cabinet from any surface on which it is mounted. When it is desirable to mount the cabinet on the
floor a floor stand, ED-95023-70 Group 2, can be used and where appearance is a factor a cover for
the base of
th e stand, ED-95023-70 Group 4 can be provided. One floor stand foot and cover are
shown in Figure 6. One ED-95023-70 Group 2 and 4 is required to provide the two foot assemblies
and covers neces3ary to support one cabinet.
The 16A apparatus mounting and cover have overall dimensions of 26
1
~" x 16-it;" x 9%". The
cover has a beige gray wrinkle finish and is furnished with an inner lining of sound absorbent material
for noise reduction purposes. The apparatus mounting has a hinged gate assembly affording easy
access to
the terminal side of mounted apparatus , the gate assembly providing two rows of mounting
space each 7" high {see Fig. 7) each row having horizontal space available for any number of key
telephone units with a total horizontal
requirement of 21
1
~" or less.
19

co .... ' ft.
200EW Key Telephone Unit with an Additional
202B Key Telephone Unit (Cabinet Cover Removed)
FIGURE 7
II •u
The gate assembly is also arranged for mounting six 2" x 23" apparatus mounting plates which
permits a combination of panel type
and mounting plate type units to be mounted in the same cabinet.
The shorter
19" mounting plates may be mounted in the cabinet by using adapters per P-36B209. Two
adapters
are required for each plate to be mounted.
For small installations of panel type key equipment units a smaller cabinet consisting of a 173A
Backboard, a 15A
Apparatus Mounting Assembly and ll6A W Cover is available. This cabinet is 16%"
high and l3:lV' wide and 9%" deep. The apparatus mounting assembly provides two rows of mount·
ing space each 7" high, each row having horizontal space available for any number of key telephone
units with a total horizontal
requirement of lOTt; inches. Although the cabinet is primarily intended
for wall
mounting and not arranged for floor support, the floor stand ED-95023-70 Groups 2 and 4
can be used by drilling the cabinet backboard as required.
20

Small individual angle bracket type
key telephone units such as the 3A, 11A,
16A, 31A, (Fig. 8) etc. can be mounted
on the 15A or 16A apparatus mounting
by using a mounting bracket assembly
P37B204. Using this assembly three single
space
or one double space and one single
space key telephone units of the angle
bracket type can be mounted on the front
and rear of the bracket.
Extension
auxiliary uprights, ED-
05023-70 Group 6 can be provided when
it is desirable to
mount the l01G Power
Plant on the same stand with the cabinet.
With this
arrangement the l01G Power
Plant will be located above the equipment
cabinet with approximately 2" separating
the two units. Should it be desirable to
mount the 101G Power Plant on a separate
floor stand a metal stand ED-95023-70
Group 3 is used.
Three other apparatus cabinets which
are available can be used for mounting
key telephone units of the angle bracket
Fig. 8-2-31A Key Telephone Units m-ounted front
and rear on P-37B204 Angle Bracket mounting.
or mounting plate type .. These cabinets which have a capacity of 4, 1%/' x 19" Mounting Plates or 11
or 18 mounting plates 1%" x 23" are available per ED-91472-70, ED-91194-70 and ED-91180-70
respectively. When it is necessary to mount angle bracket type units in these cabinet bent bars per
ED-60143-70 Group 1 for 19" mounting plates or Group 2 for 23" mounting plates are used. The
hent bars, furnished in pairs, are designed to occupy the space of one or two 13,4" mounting plates
and provide for mounting three single space or double space key telephone units on both front and
hack, thereby giving a capacity of six key telephone units per set of bars.
The 4-plate cabinet uses bent mounting bars 19" long per ED-69143-70 Group 1 and the 11
and lB-plate cabinets use bent mounting bars 19" or 23" long as required. The 11 and 18 plate cab·
ind>~ are arranged for 23" mounting plates but each may be equipped with auxiliary framework to
p(~rmit the mounting of 19" mounting plates. By using special adapter angle, mounting angles
l':r; A502 for 23" spans or P37 A823 for 19" spans, the 200 series Key Telephone Units and the
bracket P:17B204 may be mounted in the eleven or 18 plate apparatus cabinets or on relay rack
dc~igned for 19" or 23" mounting plates. Two mounting angles are required for each row of panel
type units or brackets.
STATION SET CONNECTIONS
i\ ten ltmninal connecting block, 44A, is used to terminate key telephone set cords having more
than four conductors. The 44A Connecting Block may be used individually or in a group arrange-
ment of up to four blocks.
The No~. lOlA-4 (Ivory) or 101A-9 (Brown) covers are used with a single No. 44A Connecting
Block and two or three No. 44A Connecting Blocks may be mounted under the No. 101C-4 (Ivory)
or lOlC-9 (Brown) covers. The Nos. 168A-4 (Ivory) or 168A-9 (Brown) Backboards are arranged
21

for mounting one No. 44A Connecting Block and the Nos. l68B-4 (Ivory) or _l68B-9 (Brown) Back-
boards are arrang ed for mounting two or three No. 44A Connecting Blocks. Th e Nos. l68C-4 (Ivory)
or l68C-9 (Brown) Backboa rds are arranged for mounting four No. 44A Connecting Blocks. One
lOlA Type and one lOlC Type Cover are used when f our 44A Connecting Blocks are mounted on a
l68C Type Backboard.
Three No. 44A Connecting Blocks
and No.
lOlC -4 Cover
FIGURE 9
One No. 44A Conn ec ting Block
and No.
lOlA-4 Cover
The following table associated with Fig. 10 indicat es the terminals on which the various pairs
of inside wiring cable and key telephone set cord conductors are terminated on No. 44A Connecting
Blocks. The first group of ten conductors is for th e first connecting block (on e nearest butt of cable)
and the second, third and fourth groups are for the second, third and fourth connecting blocks respec-
tively. The cord attach es to th e last block on the side opposite the side where the cable enters.
FIGURE lO
Four No . 44A Connecting Block~. One Nos. lOlA and 101C Co vers Required
22

-
•
TypeD
TypeC
Inside
Inside
Connecting Wiring
Wiring
Block Block
Cable
Cable
Cord
No. Terminals
Pairs
Pairs
Conductors
l Blue / Blue Red
2 White White Green
4
Orange)
Orange Yellow
5 White White Black
1 6 Green ) Green Blue
7 White White White
-"9'\ Brown)
Brown *Brown-Red
I 10/ White White *Brown-Green
,__..-3
Slate ) Slate *Brown-Yellow
8 White White *Brown-Black
l Blue Blue-White Brown-Blue
2 Red White Brown-White
4 Orange Blue-Orange Red-Green
5 Red White Red-Yellow
2 6 Green Blue-Green Red-Black
7 Red White Red-Blue
9 Brown Blue-Browjl Red-White
10
Red'
White Green-Yellow
3 Slate Blue-Slate Green-Black
8 Red White Green-Blue
-.
l Blue Orange-White Green-White
2 Black
'White
Yellow-Black
4 Orang'e Orange-Green Yellow-Blue
5 Black White Yellow-White
3 6 Green Orange-Brown Black-Blue
7 Black White Black-White
9 Brown Orange-Slate Blue-White
lO Black White Slate
3 Slate Green-White Slate-Red
8 Black White Slate-Green
l Blue Green-Brown Slate-Yellow
2 Yellow White Slate-Black
4 Orange Green-Slate Slate-Blue
5 Yellow White None
4 6 Green Brown-White Slate-White
7 Yellow White None
9 Brown Brown-Slate Slate-Brown
10 Yellow White None
3 Slate Slate-White Brown
8 Yellow White None
* Double red, double green, double yellow and double
black in cords with
rubber insulated conductors. These
conductors have ribs to distinguish them from the others
in the cord.
FIGURE lOA
23