Bell 503-603-101 Service Manual

BELLSYSTEMPRACTICES SECTION 503-603-101
AT&TCo Standard Issue 5, October 1980

2872A1M OR 2872A2M "TOUCH-A-MATIC ®'' TELEPHONE SET

IDENTIFICATION, INSTALLATION, CONNECTIONS,

OPERATION, AND MAINTENANCE

CONTENTS PAGE CONTENTS PAGE

1. GENERAL ........... 2

2. IDENTIFICATION ......... 3

A. Design Features ....... 3

B. Optional Features ...... 3

C. Ordering Guide ....... 4

D. Operating Features ...... 6

3. INSTALLATION ......... 7

STANDARD INSTALLATION ..... 7

Installation Check Procedure . . . 8

OPTIONAL APPARATUSINSTALLATION . 10

A. D-180492 Kit of Parts (With

Speakerphone) ........ 10 B. Change A Number In Memory . . 20

B. D-180493 Kit of Parts (Dial Tone C. Delete A Number From Memory . 20

Detectorand One-TouchCalling Switch)

............. 10 D. Automatically Dial A Number From

C. D-180494 Kit of Parts (2/4-Wire

Service) .......... 11 E. LAST NUMBER DIALED Feature . . 20

D. D-180818 Kit of Parts (RecordDisable F. End-to-End Signaling ..... 21

and Dial Intermix Features) . . . 11

E. Single Line Service ...... 13

• A. Trouble Analysis ....... 21

F. Head Telephone Set ..... 13

COMPONENT LOCATION AND ACCESS

INFORMATION ......... 13 C. Memory .......... 22

A. Locationof Components .... 13

B. Mounting Cord ....... 14

C. Network Terminals ...... 15

D. Power Supply (PSB) Terminals . . 15

E. Line Key Removal ...... 18

F. Faceplate Removal ...... 18

G. Handset Cradle Removal .... 18

H. Housing Removal ....... 18

4. CONNECTIONS ......... 19

5. OPERAI_ION .......... 19

A. Record A Number Into Memory . 19

Memory .......... 20

6. MAINTENANCE ......... 21

B. Battery .......... 22

Not for use or disclosure outside the

Bell System except under written agreement

NOTICE

Printed in U.S.A. Page 1

SECTION 503-603-101

CONTENTS PAGE 1.02 This section is reissued to:

D. Dial ........... 22 . Revise Table A

E. 6-Button Line Key ...... 22 • Add Fig. 6

F. Ringer .......... 23 • Add safety information for the 95B1 power

unit

G. Buzzer .......... 23

• Add 533K diode for dial restriction

H. Handset Jack ........ 23

h Handset .......... 24 • Add 2012D transformer

J. Faceplate .... ..... 24

• Show 2012B transformer MD

K. Speakerphone ........ 25

• Show 3B speakerphone MD

1. GENERAL

1.03 The 2872AIM (MD) or 2872A2M telephone

1.01 This section contains information on the set is factory-wired for use with 1A1, 1A2,

2872AIM (MD)or 2872A2M (TOUCH-TONE ® or 6A key telephone systems (KTS). They may

Dial) TOUCH-A-MATIC telephone set (Fig. 1). be converted (Table J) for use with 1A KTS.

HANDSET MEMORY

35-TYPE DIAL

HOUSING
(UPPER)

H4DU CORD FACEPLATE

Fig. 1--2872AIM (MD) or 2872A2M Telephone Set

Page 2

HOUSING
(LOWER)

ISS5, SECTION503-603-101

1.04 The telephone sets are available in the • Polarity guard (removable for dry circuit

following colors: application)

• Black (-03) • Common audible ringing

• Green (-51) • Buzzer

• White (-58) • Busy lamp diode

• Lt. Beige (-60). • Line pickup buttons convertible to nonlocking

1.05 The 2872A1 (MD) faceplate is available in

satin-silver (-87) color only. • Memory buttons from which to select

1.06 The 2872B1decorative faceplates are available automatic dialing

in the following colors:

• Teak Woodgrain (-108) 31 telephone numbers of up to 15 digits

• Walnut Woodgrain (-109)

• Matte Aluminum (-122).

2. IDENTIFICATION

2.01 The 2872AIM or 2872A2M telephone set tones during automatic dialing (WAIT input)

provides all standard features of a 6-button

key telephone set plus (manual) TOUCH-TONE • End-to-end signaling for data application.
dialing, automatic dialing of 31 frequently called

numbers, and a LAST NUMBER DIALED scratch
pad memory.

2.02 The 2872A2M telephone set differs from

the 2872AIM set only in the battery circuit. 2.04 Optional Features (Refer to Table A):

The 2872A2M set has a battery interlock circuit
that prevents the set from dialing automatically if

the battery is not plugged in. Also, the 2872A2M • Speakerphone--either $3B (MD)¢ or 4A
telephone set utilizes a newly coded battery speakerphone systems may be added to

(KS-20390L4) which can not be used in the 2872AIM stations
set.

A. DesignFeatures

2.03 Design Features: detector and speakerphone)--depressing one

• Modular key telephone set speakerphone, detect dial tone, and dial

• Integrated circuit RCTOUCH-TONE oscillator

• Integrated circuit memory process of placing a call must be precise

• Surge protector completed automatically.

signal buttons

preprogrammed telephone numbers for

• Capability to record and automatically dial

each

• Last number manually dialed memory

• Plug-in battery

• Capability to pause for subsequent dial

B. OptionalFeatures

• Dial Tone Detector--automatically starts
dialer when precise TOUCH-TONE dial tone

(350 Hz and 440 Hz) is present.

• One-Touch Calling, (requires both dial tone

memory button will automatically turn on

complete number.

Note: All dial tones encountered in the

TOUCH-TONE dial tone if the call is to be

Page 3

SECTION 503-603-101

• IPD-180818 Kit of Parts provides the following C. Ordering Guide

features.

2.06 Ordering Guide:

Note: Telephone set must be equipped with

2870B memory. (a) The 2872A2M telephone set is a modular

(a) Record Disable--turns off recording complete and ready to install as:

feature to prevent accidental erasures

of previously stored numbers. No recording • Set, Telephone, 2872A2M-*

possible except for last number dialed
memory which will store digits manually (b) Ordered Separately.

dialed from the telephone set.

(b) Record Disable and Dial Intermix of the automatic dialing feature).

Feature--digits dialed manually from

the telephone set dial and digits dialed Note: One power unit is required for each
automatically from memory may be telephone set.

intermixed without depressing RECORD
OFF button. Memories cannot be altered • Decorative Faceplate, 2872B1-108 (Teak
and LAST NUMBER DIALED feature is Woodgrain) or2872Bl-109 (Walnut Woodgrain).

inoperative.i

• Station Busy Lamp (busy lamp diode wired component parts:
in set)

• 2/4-Wire Service

• Add-On-Conference 2872B1 faceplate)

type telephone set and may be ordered

• Unit, Power, 95B1 (required for operation

(c) The 2872A2M set is comprised of the following

• Housing, Lower, 870A1-*

• Housing, Upper, 870AIU-* (used only with

• Exclusion (multiline) • Faceplate, 2872B1-122 (matte aluminum)

• 'T' Hold • Handset, G15A-*

• Signaling • Cord, Handset, H4DU-*

• Bridged Ringing • Base, Telephone Set, 2872A2M (includes the

• Restricted Dialing

• Amplifying Handset

• Decorative Faceplate

• Head telephone set operation using jackset. Ringer, PIB

2.05 AII options are implemented by:

• Wiring changes in the telephone set

• Installation of appropriate additional items. *Add appropriate color suffix (paragraph 1.04).

Page 4

following):

Dial, 35AG3A

Key, 635BT5

812365039 (P-23F503) Collar

Network, 425K (MD) or 4228-type

Buzzer, KS-20419L1

Cord, Mounting, D50BB-87

ISS 5, SECTION 503-603-101

$ TABLE A 0

OPTIONS

, , | i , , , , , ,, ,

OPTION ADDITIONAL ITEMS REQUIRED

CONNECTION PER

FIGURE TABLE

, , , , , , , , , ,, , , , , , , , , , ,, , , , ,

108AA Loudspeaker 12 D, E

680AE Transmitter 12 D, E

4A 82B Connecting Block 12 D, E

85B1 Power Unit 12 D, E

D-180492 Kit of Parts 9(C) D, E

Speakerphone*

760A (MD) Loudspeaker 11 B, C

666B (MD) Transmitter 11 B, C

3B (MD)

55-Type (MD) Control Unit 11 B, C

2012D Transformer 11 B, C

149B Adapter B, C

D-180492 Kit of Parts 9(C) D, E

D-180492 Kit of Parts 9(D, E)

One-Touch Calling .¢ C, E

Speakerphone 9(B)

Dial Tone Detector D-180493 Kit of Parts 9(D) C, E, F

Station Busy Lamp 10
"I" Hold 10

Signaling H

Exclusion (Multiline) 10

Ad d- On-C on fere nce 10

Amplifying Handset G6BM, O7BM, or G8BM Handset 9(H)

2/4 Wire Service* D-180494 Kit of Parts 13 G

Dry Circuit (without Polarity Guard) 9(B)

1A Key Service J

Restricted Dialing 533K Diode, Capacitor (_. 5MF) 14

Bridged Ringing L, M

Record Disable

D-180818 Kit of Parts (See Note 1) K

Dial Intermix

Page 5

SECTION 503-603-101

, $ TABLE A (Contd) e

-- , ,, , , , , , ,, , , ,, ,,, ,

OPTION ADDITIONAL ITEMS REQUIRED

,,, ,, , , , , ,,, ,,, , ,, , , ,, , , ,, , , ,,, ,,, , , ,, , , ,

Decorative Faceplate

,, , , , , ,,,, , , ,

CONNECTION PER

FIGURE TABLE

2872B1-108 (Teak Woodgrain)t

2872B1-109 (Walnut Woodgrain)t

Plantronics Jackset Model Tables provided with

JS0180-1A or JS0180-2A Plantronics Jackset

Head Telephone Set Operation I

OPTIONS

. . ,,,,,, , . ,,. . . . . ,, ,

Desired Head Telephone Set

Note 1. If set is equipped with the 2870A memory, replace with a 2870B memory.

Note 2. Set must be equipped with 4228-type network.

* D-kits for 2/4-wire service and speakerphone are designed to mount in the same place in the set. If both services

are to be provided simultaneously, consult your Telco engineer.

An 870A1U- upper housing may be required(paragraph 6.11).

The KS-19796, KS-20778, 52o, 53-, and 60-type headsets are registered with the Jackset Models.

Battery, KS-20390L2 [may be used in either • Kit of Parts, D-180818 (Record Disable and
2872A1M (MD) or 2872A2M sets] Dial Intermix)

Battery, KS-20390L4 (2872A2M sets only) Note: This kit of parts may be used only

Jack, Handset, 616B

with sets equipped with a 2870B memory

• Faceplate, 2872Bl-t

Memory, 2870B

Note: If set is equipped with 2872A1-87
840393581 Power Supply Printed Wiring faceplate, then an upper housing (870AIU-*)
Board (PSB) Assembly [2872AM (MD) base] of the appropriate color must also be ordered.

841382658 Power Supply Printed Wiring • Handset, Amplifier (G6BM, G7BM, and
Board (PSB) Assembly (2872A2M base) G8BM)

840393672 Directory Sheet Set • Set, Head Telephone [using Plantronics Jackset

Model JS0180-1A (1-1/2 foot cord) or JS0180-2A

Booklet, Instruction, Subscriber, SIB-2455B (6 foot cord)].

(d) Optional Apparatus (order as required):

D. Operating Features

• Kit of Parts, D-180492 (must be used for

speakerphone service) 2.07 Operating Features (Fig. 2):

• Kit of Parts, D-180493 (Dial Tone Detector • Dial (TOUCH-TONE dial).
and One-Touch Calling switch)

• Add appropriate color suffix (paragraph 1.04).

• Kit of Parts, D-180494 (for conversion to

4-wire service) _Add appropriate color suffix (paragraph 1.06).

Page 6

ISS 5, SECTION 503-603-I01

• Line key (635BT5), 6-button key. Hold with Note: Write date of installation on label
five line pickup buttons which are convertible provided on battery.

to nonlocking. An additional momentary
contact (logic reset switch) is attached to 3.03 Install the 95B1 power unit within 150 feet

the Hold side of the key to reset the logic (24 gauge conductors) of the telephone set
circuit anytime a key button is depressed, and plug into an ac outlet not controlled by a switch

• 32-button array of low force, low travel clamp (841050818) will be shipped with the 95B-type
nonlocking memory buttons arranged in three power unit and should be mounted to the ac

columns. Left and right columns have eleven receptacle to hold power unit securely and prevent
buttons, center column has ten buttons, accidental loss of power. The power unit may be

• LAST NUMBER DIALED button located in directly into the telephone set by conductors

lower right corner of memory array, when separate from the mounting cord and connected to
momentarily depressed, automaticallyredials PSB terminals 30 and 31. Refer to applicable

the last number manually dialed, tables and Fig. 8 for particular type of installation.

• RECORD button (nonlocking), when momentarily insulate, and store the (BL-V) and (V-BL) mounting
depressed, lights the RECORD lamp and cord leads from PSB terminals 30 and 31.

enables the memory circuits to store telephone
numbers. Danger: Securely attach retaining

• RECORD OFF button (nonlocking), when screw BEFORE attempting to instaIl
momentarily depressed extinguishes the 95B1 power unit. OThe power unit
RECORD lamp, indicating that the dialer is and any other cord plugged into the

switched out of the record mode. ae outlet should always be unplugged

• WAIT button(nonlocking),whenmomentarily attempting to attach or remove the

depressed during recording operation, enters retaining clamp. This will prevent

a code into memory to initiate a halt in the possibiIity of a loosened retainer

the automatic dialing sequence [used where clamp or metallic outlet cover making
access digit(s) required], contact with the ae prongs of the

3. INSTALLATION clamps on outlets where the cover
STANDARD INSTALLATION in the box.

(continuous ac power is required). A retaining

located at the equipment end of the cable or run

When separate power conductors are used, disconnect,

eIamp to ae outIet using outlet cover

completely4 from the outlet BEFORE

power unit when partially withdrawn
from outlet. Do not use retaining

mounting screw holds the duplex outlet

3.01 Make all wiring changes and telephone set SWarning: Care should be taken to

modifications (Table A) before external trim and dress leads connecting to

connections are made to the set (paragraph 4.01). low voltage output terminals of 95B1

Warning: Do not plug in either battery connection to conducting surfaces or

or power unit until all connections other power source does not occur.
and modifications are completed. Take If more than one power unit is

extreme care not to damage the plugged into a multiple receptacle

exposed components, circuit, etc. when power strip, there must be at least

the set is opened, one inch separation between power

3.02 The set is shipped from the factory with power strips with adequate power

the battery disconnected. After all wiring rating shall be used. Use of a

changes and modifications have been completed, continuous terminal power strip that

connect the battery (Fig. 7) by tilting the set up, allows the secondary output terminals

and inserting the battery plug into the mating jack. of the power unit to be in close

power unit to assure that inadvertent

units. Only UL listed receptacle

Page 7

SECTION 503-603-101

CORD

J MOUNTING 655-TYPE KEY COVER

LINE SWITCH LABEL
PLUNGER

HANDSET
CRADLE

DIRECTORY DETAIL REMOVED WHEN
SHEET D-180493 OR D-180818

CAPTIVE HOUSING INSTALLED

SCREW (4)

INSTRUCTION

KIT OF PARTS IS

Fig. 2--2872A2M Telephone Set--Faceplate and Handset Removed

COVER

SCREw

proximity to the ac line source is not (4) Replace the caps so that small bumps on
recommended.Q side of caps fit into small holes on sides of

buttons.

Note: The 95B1 power unit must be located
no closer than 1-1/2 feet from the telephone
set in order to prevent a noise problem. Installation Check Procedure

3.04 The station number card retainer 812558039 3.07 Check telephone set installation per the
(P-25ES03) snaps into the faceplate below following tests(referto Part 5 for operation).

the dial. In case of failure, refer to Trouble Analysis, Table

N.

3.05 The directory sheets (Fig. 2) fit over the

buttons of the memory and are held in place (1) Disconnect the power unit and manually dial
by the faceplate. Additional sheets are available a known telephone number to check that
in the directory sheet set, 840393672. the telephone operates correctly in the absence

of commercial power.

3.06 To designate the buttons of the 635-type

6obutton key. (2) Reconnect the power unit to ac outlet.

(1) Use Form 5837 tabs. (3) With handseton-hook, record digits 1through

0 into consecutive memory locations, storing

(2) Squeeze the sides of the key button caps one digit per memory. Fill all memory locations

gently and remove, except LAST NUMBER DIALED and location

immediately above it [paragraph 5.01 (4)

(3) Insert the tabs. through (7)].

Page 8

ISS 5, SECTION 503-603-101

KEY TABS .............. "

TERMINAL

B0 A R D T B 2 L:_,_::_i::'.

LINE SWITCH

ASSEMBLY

TERMINAL
BOARD TBI

PIB RINGER

BUZZER
MOUNTING SCREW

:_.:; •

616B JAC

ATTACH STAYBAND

OF NONMODULAR
HANDSET CORD

KS-20419 LI BUZZER

Fig. 3--2872A2M Telephone Set With Faceplate, Handset, Handset Cradle, and Upper Housing Removed

Page 9

SECTION 503-603-101

(4) Manually dial CO dial test and ringer circuit (9) 0Go off-hook and manually dial a known

and simultaneously record into memory telephone number with a WAIT input inserted
location immediately above LAST NUMBER in the telephone number.
DIALED button [paragraph 5.01 (4) through (7)].

After depressing RECORD OFF button, and (10) Momentarily hang up the handset and then
when dial test circuit is ready, test dial frequencies automatically dial the number by depressing

by manually dialing digits 1 through 0 into the the LAST NUMBER DIALED button. The set
test circuit, should stop dialing when it reaches the stored

WAIT input. Depress the LAST NUMBER

(5) Momentarily hang up handset and automatically DIALED button again and the remaining digits

dial the test circuit number recorded in Step should be dialed._

(4) by depressing button immediately above
LAST NUMBER DIALED button and proceed OPTIONAL APPARATUS INSTALLATION

as follows.

(a) Depress LAST NUMBER DIALED button.

Digits 1 through 0 will be automatically 3.08 To install.

dialed into test circuit. Verify that correct
signal is returned from test circuit. (1) Proceed as described in paragraph 3.16.

(b) Momentarily depress the memory buttons (2) Make connections per the appropriate Tables,

used in Step (3) in the same sequence in B through E.

which the digits were recorded. Verify that
correct signal is returned from test circuit (3) Mount the kit assembly to the chassis with

after each series of numbers, the screws provided (Fig. 4). Beveled corner

be connected a minimum of five

minutes before doing Step (c).

The battery and the power unit must at lower right corner.

(c) Momentarily disconnect the power unit

(for 5 to 10 seconds). After reconnecting 3.09 To install.

power unit, depress a memory button of a
memory location used in Step (3), to verify (1) Remove the housings (paragraph 3.21), and

retention of memory, access PSB terminal board (paragraph 3.17).

A. D-180492 Kit of Parts (With Speakerphone)

of printed wiring board (PWB) should be located

B. D-180493 Kit of Parts (Dial Tone Detector and

One-Touch Calling Switch)

(6) Dial the appropriate code for ring-back to (2) Insert the board assembly from the back of

test the ringer, the set and locate as shown in Fig. 4, such

(7) Check operation of the logic reset switch the slots in the bottom of the chassis.

by pressing the RECORD button (RECORD

lamp will come on) and subsequently pressing (3) Lock the board into position by inserting
an unoperated line button. The RECORD lamp the self-threading screw through the right

must go out. side of the chassis.

(8) If equipped with one-touch calling option the dial with the two screws provided.

(D-180493 Kit of Parts and speakerphone),

and with set in on-hook condition, depress the Note: If switch for D-180818 Kit of Parts
memory button used in Step (4). The speakerphone is already present, the one-touch calling switch

should turn on, dial tone should be detected, can not be installed. The PSB terminal where
and the stored number should be automatically the switch leads should be connected (Table

dialed. C or E) shall be strapped together. (The

Page 10

that the two tabs on the board assembly fit into

(4) Mount the one-touch calling switch below

CAPTIVE MEMORY
MOUNTING SCREWS

D-180492 KIT OF NETWORK
PARTS {OPTIONAL)

ISS 5, SECTION 503-603-101

MOUNTING HOLES FOR
D-180492 OR D-180494
KIT OF PARTS (OPTIONAL)

PARTS {OPTIONAL)

CAPTIVE MEMORY KIT OF PARTS OR FEATURE SWITCH OF

MOUNTING SCREWS D--180818 KIT OF PARTS (OPTIONAL)

ONE-TOUCH CALLING SWITCH OF D-180493

Fig. 4--2872A2M Telephone Set--Dial Removed To Show Terminal Area

one-touch calling option cannot be turned off (2) Make connections per Table G.
by the subscriber.)

(3) Mount the kit assembly to the chassis with

(5) Make connections per Table C, E, or F. the screws provided (Fig. 4).

KIT OF

TERMINAL AREA

55-TYPE DIAL

(6) Break off the detail at the bottom of the D. D-180818 Kit of Parts (Record Disable and Dial

cover (Fig. 2) and trim edge as required. Intermix Features)

(7) Verify correct operation of the option. 3.11 To install.

(8) Reassemble set. (1) Remove faceplate (paragraph 3.19).

(2) Loosen the captive screw at the bottom of

C. D-180494 Kit of Parts (2/4-Wire Service) the cover around the dial and remove the

cover.

3.10 To install.

(3) Disengage the four captive memory mounting

(1) Proceed as described in paragraph 3.17. screws (Fig. 4).

Page 11

SECTION 503-603-101

LOGIC
RESET

SWITCH

BATTERY

JACK

•. MEMORY

CONNECTION PINS
FOR D-180818
KIT OF PARTS

• DIAL CONNECTOR
CONNECTOR

POW ER SU PPLY

Fig. 5--2872A2M Telephone Set, Internal View, Overall

(4) Disengage the two captive dial mounting strapped together. (The one-touch calling

screws and move dial aside, option can no longer be turned off by the

subscriber.)

(5) Rotate left edge of the memory upward as

shown by Fig. 5. (7) Connect switch lead connectors to post

terminals on memory board per Table K.

Note: If set is equipped with a 2870A
Memory, replace it with 2870B Memory and (8) With feature switch in OFF position, verify

carefully pack and return the old memory that set operates in normal manner:
according to local procedures.

(6) Mount switch below dial using the two screws

• Numbers can be recorded into memory

provided (Fig. 4). • Numbers can be changed

Note: If the one-touch calling switch (D-180493 • Numbers can be deleted from memory.
Kit of Parts) has been provided, it must be

removed. The PSB terminals where the switch (9) Set feature switch to ON position and verify
leads were connected (Table C or E) must be feature provided.

Page 12

ISS 5, SECTION 503-603-101

• Record disable feature, only. (1) Remove housing (paragraph 3.21).

(a) RECORD lamp will not light when (2) Access PSB terminal area (paragraph 3.17).

RECORD button is depressed.

(b) No telephone numbers can be recorded,

changed, or deleted in memory. (4) Thread jackset cord through hole in rear of

(c) LAST NUMBER DIALED feature is table provided with Plantronics Jackset.

operative.

• Record disable and dial intermix features.

(a) RECORD lamp will not light when

record button is depressed. _ Other optional components may be

(b) No telephone numbers can be recorded, sets, etc. Refer to the appropriate

changed, or deleted in memory, section for connection information

(c) LAST NUMBER DIALED feature is

disabled. COMPONENT LOCATION AND ACCESSINFORMATION

(d) Manually and automatically dialed digits A. Locationof Components

may be intermixed (paragraph 5.07).

(10) Reassemble set. as follows.

E. Single Line Service (a) Under the handset cradle (Fig. 3):

(3) Remove cradle (paragraph 3.20).

housing and make connections per appropriate

(5) Reassemble telephone set.

(6) Insert head telephone set plug into jackset.

used such as SPOKESMAN _ loudspeaker

for these components.

3.14 The components are located in three areas

3.12 The 2870A2M TOUCH-A-MATIC telephone • Buzzer

set is available from the factory as a single

line set. However, the 2872AIM (MD) and 2872A2M • Ringer
telephone sets may be converted to single line

service as follows. • Line switch assembly

(1) Remove the faceplate, key collar, and all • Handset jack

buttons of the 635-type key.

• Terminal boards (TB1 and TB2).

(2) Gain access to terminal area (paragraph

3.17). (b) Under the faceplate, inside the set (Fig. 4
and 5):

(3) Remove the cradle (paragraph 3.20).

• Battery jack (Fig. 5)

(4) Make connection per Table L.

• Power supply (PSB) terminal area (Fig. 4)

(5) Reassemble set and install a 2870B1 faceplate

of the appropriate color. • Network (Fig. 4)

Note: If set was originally equipped with a • Options (Fig. 4):

2872A1-87 faceplate, refer to paragraph 6.11.

D-180492 (relay kit for speakerphone)

F. Head Telephone Set

D-180493 (dial tone detector and one-touch

3.13 To install, calling switch kit)

Page 13

SECTION 503-603-101

D-180494 (2/4-wire relay kit) with 508-type plugs for terminating on the bac_

D-180818 (record disable and dial intermix end. The conductors terminated in the 508-type!
feature switch) plugs provide the major line service requirements.i

(c) Bottom of telephone set (Fig. 7). control functions or options and are terminated

• Battery. or stored.

B. Mounting Cord Note: Sets manufactured prior to fourth

3.15 The D50BB-87 mounting cord is amphenol mounting cords. The major difference in the
ended at the equipment end and equipped cords is that TIP and RING contact strips

of the 635-type key module at the telephone set

Spade-tipped conductors are provided for auxiliary'

directly on associated equipment, terminal boards,

quarter 1976 were equipped with D50AM-87

Fig. 6--$2872A1M (MD) or 2872A2M Telephone Set, Connection of D-180818 Kit of Parts, Record Disable

Feature Only_l

Page 14

ISS 5, SECTION 503-603-101

Fig. 7--2872AIM (MD) or 2872A2M Telephone Set, Bottom View

were required with the D50AM-87, whereas (3) Remove the cover.
individual conductors of the D50BB-87 connect

to the TIP and RING contacts of the 635-type (4) To replace the cover, the three tabs of the
key. cover (one at the top center and one at each

C. Network Terminals holes in the chassis before the screw is refastened.

3.16 For access to the network terminals, of the faceplate.

(1) Remove the faceplate (paragraph 3.19). D. Power Supply (PSB), Terminals

(2) Loosen the captivecover screw at the bottom 3.17 To access the terminal field on the power

of the white cover around the dial (Fig. 2). supply board, proceed as follows.

side just above the dial) must be aligned with

Failure to do this will result in improper seating

Page 15

SECTION 503-603-101

TOUCH-A-MAT I C

TELEPHONE

SET

_/ 1 '95B-TYPEI D-STATION WIRE ;

II 7 VAC _ POWER | MOUNTING CORD

(NOTES1AND 4) L UNIT J (NOTE ._)

149B ADAPTER

(NOTE 2) _"_ (NOTE 2) ___ t

,,7 VAC__ "

(NOTES \ 6) t

J 1D-STATION

' 1

,- (

--I _-TY_po_t--I_'"_ _,_

IAND4) I UNIT I I 0 I

TO KEY TELEPHONE SYSTEM _"

(NOTE 2 ) _ 31 40

NOTES: (20) t

I. THE 95B-TYPE POWER UNIT MAY BE CONNECTED 50

ADAPTER OR 66E3-25 CONN. BLOCK, OR AT KEY _ CONN BLOCK

TO AC POWER AT SET LOCATION, AT 149B I'_0 i i iI 66E3-25
EQUIPMENT END. SEE PARA. 3.03. _J,'46_I ,_;1'21_ (25) t (NOTE 2)

2. IF THE POWER UNIT IS TO BE CONNECTED AT --t'--I

THE 149B ADAPTER OR THE 66E3-25 BLOCK, I I D-STATION

INSULATE AND STORE THE (BL-V) PAIR AT THE I I 95B-TYPEI

KEY EQUIPMENT END. LI WIRE POWER LL117 VAC

3. INSULATEAND STORE THE (BL-V) AND (V-BL) UNIT • (NOTES
MOUNTING CORD LEADS FROM PSB TERMINALS. | I AND 4)

4. A 95B-TYPE POWER UNIT IS REQUIRED FOR EACH
TELEPHONE SET. _ C.O.

f NUMBERSIN PARENTHESESINDICATE

CONNECTOR PiN NUMBERS -- --

Fig. 8--2872AIM (MD) or 2872A2M Telephone Set, Alternate Power Connection Methods

,., (31) (I0) t
.j 21 30

=_.
< (36) (15) t

1

KEY TELEPHONE SYSTEM

,- ---- --- 95B-TYPE

4_ (NOTES

66B4-25 CONN BLOCK

OR EQUIVALENT

D'STATION I L

J_>W,RE I POWER L If7 VAC

IUNIT I

I AND 4)

Page 16

ISS 5, SECTION 503-603-101

TABLE B

CONNECTIONS - 2872AIM OR 2872A2M TELEPHONE SET WITH 3B (MD) SPEAKERPHONE ONLY

.... , , i ,

LEAD

TEL. SET FROM TO

CONNECT

APPARATUS (NOTE 1) 149B ADPT

CONT UNIT (D10R

DESIG COLOR CORD)

, , , , , , , ,, , = ,,,, , , , , ,,

FROM

TO PSB
TE RM. 55A 55B TERM.

(NOTE 2)

T1 V-G * 2 19 1 8A
R1 G-V * 11 28 10 7A

A1 12 2 A1

AG

LK S-V * 17 11 35 IIA

Tel Set R or R1 18 34 1B

R or R1 9 25 1A

V-S * L2_f 5 11 12A

i

| ,,,

B or B1 I 17 33 2B
B or B1 8 24 2A

Strap ] BK PSB10 *
Strap BK PSB20 *
CE BL-BK 10

B+ BK-BL 15

D-180492 SHa 1 R-BL 16

Kit LK BL-R 17

of

Parts SHi G-W 18

PrR BL-V 20

VDD W-G 21
M1 "S'BK 4 7

P1 BL-R 13 8

666B --15V BK-S 14 16

TRMTR. S O-BK 3 18

(T7A Cord) A1 Y-O 29 19

F1 i G-Y 2 17
LK BK-O 11 35

760A LSPK SP1 G 34 20

(R2FK Cord) SP2 R 335 295

95B-Type AC1 § _,

Pwr-Unit AC2 4B §

2012B (MD)or AC1 27 27

2012D Trnsf AC2 ! 36 36

.......

• Insulated and stored.
t" Terminal on network.

5 To reduce loudspeaker volume, move SP2 lead to terminal 24 (55A) or 30 (55B)

§ Insulate and store (BL-V) and (V-BL) leads in connector cable.

Note 1 • Plug telephone set mounting cord into 149B adapter.
Note 2: When 55A control unit is used, it must be the type modified for TOUCH-TONE, and strap terminals

20 and 21 (55A) or 4 and 5 (55B).

........

3B

,, ,

Poge 17