Bell System 4A User manual

(
I
( )
BELL SYSTEM PRACTICES
AT & TCo Standard
~lON 518-450-106
Issue !, December 1977
4A COMMUNICATION SYSTEM
(COM KEY* 416)
USING 981/2981- AND ... /2913-NPE TEti:PHONE SETS
CONTENTS
1.
GENERAL
2.
IDENTIFICA liON
BASIC FEATURES
OPTIONAL FEATURES
TELEPHONE SETS
PBX INTERFACE
ORDERING GUIDE
A. Basic Apparatus
B. Optional Apparatus
c.
•••- t l.lillitr''lfPi''fili~. ··
3.
INSTALLATION AND CONNECTION
PlANNING
•·
POWER REQUIREMENT$,
CABLING RESTRICTIONS
SYS1'EM CABLING AND CONNECTIONS
TELEPHONE SETS
Primary Sets
Basic Sgtellite
and HFAI Desk Sets
BIS Desk Sets
Basic Satellite Wail
Sets
*Trademark
2
4
4
CONTENTS
~~·_WaD S.ts
AN HFAI Sets
PAGE
23
• .. · ~- 25
25
. BASIC. FE4.,~
26
8
10
10
11
11
12
fl
17
17
18
18
"'
19
19
19'
20
20
Printed in U.S.A.
CO/PBX and Intercom 'if.lt AssigniJI~J$
(Primary Sets Only) . . • . . . 26
CO/Rl.X Rll\fiWft and DSS Code
Assignments ,(All Sets) 26
OPti&NAL FEA lURES
27
....
Supplementary Power Using l~
Power Unit 27
Music-on-Hold 28
,..-on-Hold
;.,.1'2
Paging Using 109A Loudspeaker
~a
Paging Using 27 A Apparatus Ultlt
and Customer Paging SysteJJ'I vfi!UJA}
Power ""\ut:• Ringing {24A '"' 2 ..
Apparatus Unit) • . . . : . •
-' ~.....-:.:-. ~ ,"" /',
Supplementary Alerting Device Access
31
31
. .
35
37
(25A Apparatus Unit) 38
:::. " ·.t·d\-~
Preset Multiple Voice Sitlnali~ .. ·(26A
Apparatus Ufljt) '· r• •. i;t~K~ 38
Station' Dial Restridion
~l.uifJ
u!.'
40
41

SECTION 518-450~ 106
CONTENTS PAGE
Personal line
41
Code Busy
DSS Key
46
4A Speakerphone
47
Repertory Dialing
49
External Ringing
50
FINAL SYSTEM CONNECTIONS
50
4.
METHOD OF OPERATION
51
ANSWERING CALLS USING HANDSET
51
PLACING CALLS USING HANDSET
51
HOLD OPERATION
52
ANSWERING CALLS USING BUll T-IN
SPEAKERPHONE • • . • 52
PLACING CALLS USING BUILT-IN
SPEAKERPHONE . • . • • . . • 52
Built-In Speakerphone Operating Features
52
ANSWERING INTERCOM CALLS AT HFAI
STATION • . . . . • 53
•
HFAI Operating Features 53
CALLING AN HFAI STATION
53
4A SPEAKERPHONE OPERATION
54
MISCELLANEOUS OPERATING TECHNIQUES
54
5. MAINTENANCE 55
DIAGNOSTIC
PROCEDURES
56
DISASSEMBLY AND ASSEMBLY OF TELEPHONE
SETS
56
Faceplate
56
Upper Housing 61
Page 2
CONTENTS PAGE
Lower Housing {All Satellite Desk Sets)
62
Wall Housing (All Satellite Wall Sets)
63
Low~r Housing (Primary Sets) 65
REMOVAL AND INSTALLATION OF
COMPONENTS 66
DSS Key 67
Dial 67
Loudspeaker Assembly 68
Handset Jack 68
Recall Key 69
Loudspeaker Volume Control
69
line Key
69
BIS Module
70
HFAI Module
71
Amplifier
71
Voice Signaling Interface Circuit
72
Interconnect Field Assembly
72
Base and Logic ASsembly
73
Power Transformer
73
1. GENERAL
1.01 This section provides identification, installation,
connection, and maintenance information for
the 4A Communication System
(COM KEY
using 981/2981- and 983/2983-type_telep!,Ione
-:.~-f'!•..:' ... ~-~:
1.02 This section is reissued to:
• Revise Table B
(
(

7
• Add installation and connection information
for
the
new model 109A loudspeaker
set
• Add installation information for
the
F
-60591
kit
of parts, a resistor network required in
some systems
• Add information on personal line ringing
• Clarify instructions for mounting BIS and
HF
AI wall sets
• Remove all information on headset operation
• Change Fig.
21
to show
the
plastic guide
block around the line assignment, music/tone,
and power connectors
•
Change
procedure
for
testing
replaced
loudspeaker
• Add installation and connection information
for
the
24B
apparatus
unit
(power failure
ringing)
• Change procedure for testing replaced voice
signaling interface circuit
• Add new Table E showing mounting cord
connections for adjunct repertory dials
• Expandinstructionsfor mounting BIS module
• Make minor changes and corrections
to
text
and illustrations.
1.03
The 4A System is a packaged, modular key
telephone system having a maximum capacity
of
16
stations with four common CO/PBX lines,
one personal CO/PBX line
per
telephone, and two
intercom paths. A wide selection of basic
and
optional features is available (see
Part
2).
The
system includes five types
of
telephones: (1)
primary sets, (2) basic satellite desk sets, (3) basic
satellite wall sets, (4) satellite sets with built-in
speakerphone (BIS), and (5) satellite sets with
hands-free answering on intercom
(HF
AI). Each
primary.
set
contains
the
control circuitry for two
CO/PBX lines and one intercom
path
and
the
power circuitry to serve itself and some combination
of up to seven satellite sets. The addition of a
second primary
set
doubles
the
capacity of
the
system; up
to
seven more satellite sets can be
connected, with each station in
the
system now
ISS
2,
SECTION
518-450-106
served by up to four CO/PBX lines
and
two intercom
paths. The satellite sets provide
the
same basic
services
as
the primary sets,
but
they do not
contain control and power circuits.
1.04
Because
the
control and power circuitry of
the
4A
System is contained in the primary
station sets,
there
is no need for separately mounted
key service units such
as
most key systems require.
The only equipment required in addition
to
the
telephone sets
are
interconnecting cables, blocks,
adapters, and small externally mounted units for
some optionalfeatures. Systems with many optional
features may require an externally mounted power
unit.
1.05
Each
4A
station can be programmed by,
the
customer to
ring
on
any
combination of
the
common CO/PBX lines. All stations have access
to all common lines in
the
system; therefore, any
set
can be assigned
as
the
attendant
station,
if
one is required. Each station also
has
direct access
to
the
ten intercom codes.
1.06
All
4A
telephone sets
are
available with
either
rotary
or
TOUCH-TONE® dialing.
The
primary
set is available only in a desk-type
model,
but
the
basic satellite sets can be ordered
in both desk and wall configurations.
~.
BIS
and
HF
AI sets
are
convertible from desk'(i(;'wall
mounting by means of a
kit
of
parts.
' ..,
'are
a
total
of
ten
telephone
set
codes in
the
9·
eries
(Table
A).
Fig. 1 through 5
illustrate
tyt)i¥1
sets.
..
1.07
The 4A System derives
its
ac power. from a
standard
117-volt 60-Hz source: The system
components
are
protected by a self-resetting
thermal
cutout in
the
power supply of
the
primary
station,
making separate fusing unnecessary
..
The
19B2
power unit, used when supplementary
de
power is
required,
has
both input and output
fusi~.
1.08
While
the
980-series telephones provide more
optional features
than
the
830-serjes used
with
the
earlier 4A System (Section
518'-Mo-105),
the
two series
are
compatible and interchangeable.
They can coexist in
the
same system, and
~-series
sets can be used to replace 830-seriea' .
sets
in
existing installations. However,
if
supplementary
power is required,
the
primary
sets
must
be from
the 980-series.

SECTION
518-450-106
TABLE
A
TELEPHONE SETS FOR
THE
4A
COMMUNICATION
SYSTEM
DESK
ROTARY
TOUCH-TONE
Primary
981A01
2981A01
Basic
981A02
2981A02
Satellite
BIS
983A01
2983A01
Satellite
HFAI
983A02
2983A02
Satellite
•Note:
In
a mixed system,
optional
code
busy
DSS keys
can
only give
busy
indications
for
980-series telephones
.•
1.09
Schematics of
the
telephone sets
and
apparatus
units
of
the
4A
System
are
contained
in
SD-69856-01, Issue 1. The
schematic
of
the
1A
transmitter-receiver
(built-in.
speakerphone
module)
is
in
SD-69800-01, Issue
1.
•
1.10
For
additional
information
on
the
following
subjects,
refer
to
the
sections listed.
4A
Speakerphone-Section
512-700-100
33A Voice
Coupler-Section
463-341-102
Adjunct
Repertory
Dials-Section
501-164-201
KS-16301, L17
Relay-Section
463-110-100
KS-16626,L12 Relay
Set-Section
463-120-100
19B2
Power
Unit-Section
167-440-201
Wall-Mounting
Fasteners-Section
080-720-105
E1-Type
Ringers-Section
501-251-100
Page
4
WALL
ROTARY
TOUCH-TONE
--
981A03
2981A03
983A01
2983A01
plus
kit
plus
kit
of
parts
of
parts
D-180747 D-180747
983A02
2983A02
plus
kit
plus
kit
of
parts
of
parts
D-180747 D-180747
2. IDENTIFICATION
2.01
The
4A
Communication
System
consists
primarily
of
key telephone
sets
and
various
connecting
hardware
and
cables. Basic
operating
features
are
supplied
as
part
of
the
telephone sets,
while
additional
apparatus,
installed
in
the
sets
or
externally, provides optional
features.
BASIC
FEATURES
2.02
The following
features
are
provided
in
all
4A
System
telephone
sets
and
require
·no
additional
installation.
(a)
Pickup,
Hold,
and
Illumination-Standard
key
system
pickup, hold,
and
line
status
lamp
·indications, including
flash
on incoming
CO/PBX line calls,
steady
on
answered
calls,
and
wink-on-hold
are
provided.
Systems
with
one.
primary
set
are
limited
to
two
common
CO/PBX lines;
systems
with
two
primary
sets
can
have
up
to
four
lines.
(b)
2-Path
Intercom
With
Direct
Statioo
Selection
(DSS)-Two
paths
are
prQvi.W:
for
intercom
calls, each associated
with
an
IG.
button
in
the
pickup key. A
busy
path
is
indicated
by
a
steady
lamp
adjacent
to
the
I~
button. DSS
buttons
allow one-wayvoice
signaliae
(

ISS 2, SECTION 5 18-450-1 06
Fig. 1-Primary Telephone Set
Fig. 3-Built-ln Speakerphone Satellite Telephone Set
Fig. 2-Basic Satellite Wall Telephone Set
Page 5

SECTION
518-450-
1
06
LEAD
GUIDE
HFAI
MODULE
Fig.
4-.Hands-Free-Answer-on-lntercom
Satellite Telephone
Set.
of called
stations
without dialing. A 2-way
conversation is established when
the
called
party
goes off-hook and picks up
the
intercom
path.
Ten codes
are
available; in systems with more
than
ten
stations, codes
must
be shared.
•The
intercom code is
set
at
each
station
by means
of a programming switch and may
be
reprogrammed
by
the
customer..
Systems
with
one
primary
set
are
limited to a single intercom path; systems
with two
primary
sets have two paths.
(c)
Automatic
Button
Restoration
(ABR)-Depressed
line or intercom
buttons
are
mechanically
returned
to
the
unoperated
position when
the
handset
is placed on-hook.
This prevents breaking into calls in progress
Page
6
when
handset
is picked up and prevents lines
from being left bridged
after
a conference call.
(d)
Built-In
Loudspeaker-Th
e
built-in
loudspeaker is bridged across
the
incoming
line when
the
locking SPKR button is operated,
permitting
other
people in
the
area
to
hear
both
sides of a conversation. The loudspeaker
has
a
thumbwheel volume control on
the
front
of
the
telephone. This loudspeaker also receives tone
and voice signaling.
•Note:
In BIS sets and
HFAI
sets with
4A
speakerphone added,
the
bridging feature is
di
sabled
for
the
built-in
loudspeaker a
nd
provided by
the
speakerphone.
•

ISS
2, SECTION
518-450-1
06
Fig. 5- Basic
Satellite
Desk Set
Wi
th Facep
late
a nd U
pp
er
Housi
ng
Removed
(e)
Tone
Signal
i
ng
-The
alerting
signal for
incoming
CO
/PBX lines is a tone source
rather
than
conventional ringing.
It
is supplied
through
the
built-in loudspeaker. Each
station
can be individually programmed by
the
customer
to
be
tone-signaled
on
any combination of incoming
CO/PBX lines.
(f) Vo
ice
Sign
ali
ng
-Voice
signaling
rather
than
ringing or tone is provided on
the
intercom paths. The calling
party
alerts
the
called station by voice while holding down
the
appropriate DSS button. The called
station
receives
this
voice signal
through
its
built-in
loudspeaker. Multiple
stations
may be signaled
by depressing more
than
one DSS
button
at
a
time. When
the
called
station
picks up
the
handset,
the
loudspeaker is
attenuated
.
(g)
Multiline
Con f
erencing-T
wo or more
CO/PBX lines can be conferenced by a
station
by
simultaneously
depressing
the
associated
locking buttons. Transmission quality is degraded
as more lines
are
added.
Note:
Intercom lines cannot be conferenced
wit
h CO/PBX lines.
(h)
Recall-The
R button, located below and
to
the
left of
the
dial on each set,
has
two
functions:
(1)
To
drop a line
and
reoriginate
dial tone without going back on-hook;
(2)
to
signal [flash]
the
attendant
when
the
4A
System
is behind a PBX
or
Centrex.
(i)
Outgoing
Serv
i
ce
During
Power
Failure-Outgoing
CO
/PBX calls can
be
Page
7

SECTION
518-450-106
made from
the
4A System even when local
power
has
failed.
OPTIONAL
FEATURES
(TABLE
B)
2.03
The
following
options
are
available
as
separately installed items
or
as
features
of
specific telephones:
(a)
Personal
Line-Each
station
in
the
4A
System can be provided
with
one noncommon,
personal CO/PBX line. Each such line requires
the
installation
of
a separately mounted 30A
apparatus
unit
which provides
standard
key
system
pickup, hold,
and
line
status
lamp
indications for
that
line. The personal line is
assigned
to
a
button
in
the
line pickup key. A
given personal line
may
be
shared
by more
than
one
station
in
the
system,
•and
it
will
ring
at
every
station
where
it
is connected.. Music-
or
tone-on-hold is available
as
an
option
with
this
feature.
(b)
TOUCH-TONE
Dialing-Rotary
dialing
can be replaced by TOUCH-TONE dialing
by
ordering'appropriate
telephone codes. Rotary
and
TOUCH-TONE dial
sets
may
be intermixed
in
the
4A System without additional equipment.
(c)
Privacy/Privacy
Release-A
station
equipped with
the
optional privacy feature
is prevented from
entering
a CO/PBX call
in
•
TABLE
B.
OPTIONS
AVAILABLE
WITH 981/2981-
AND
983/2983-TYPE TELEPHONES
TELEPHONE
SETS
OPTIONS
PRIMARY
SATELLITE
BIS
HFAI
DESK DESK
WALL
DESK
WALL
DESK
WALL
Personal line • • • • • • •
TOUCH-TONE dialing • • •
• • • •
Privacy/Privacy release • • •
• • • •
Station
restriction • • • • • • •
•
Music-on-hold*
Tone-on-hold*
Supplementary alerting*
Paging*
Preset
intercom
signaling • • • • • • •
Code busy DSS
key
• • • • • • •
Power failure ringing*
Hands-free answering • •
on
intercom
Built-in speakerphone •
•
4A
speakerphone •
Repertory
dialing • •
•
External ringing*
* System
option.
Page
8
(

progress. Privacy is implementedon a
per-station
basis by installation of a D-180729
kit
of
parts.
The
station
can be released from
this
condition
by
the
operation of
the
privacy release
feature
at
the
other
station(s) on
the
call
..
All980-series
telephone sets have
the
factory-wired PRIV RLS
button, which should be designated only when
at
least
one
station
in
the
system
has
privacy
installed.
Note:
The privacy
feature
applies to all
CO/PBX lines
but
not
to
intercom lines.
(d)
Station
Restriction-Placing
of
outgoing
CO/PBX callsfrom a
station
can be prevented
by
shorting
bar
changes inside
the
set.
(e)
Music-on-Hold-Music
from customer-pro-
vided music source is supplied
to
CO/PBX
lines placed on hold.
Installation
of
one 33A
voice coupler
per
system
and
a D-180730
kit
of
parts
in
each
primary
station
and
each 30A
apparatus
unit
is required.
(f)
Tone-on-Hold-An
alternative
to
music-on-hold,
it
provides
intermittent
bursts
oftone to CO/PBX lines placed on hold. Installation
of
a D-180731
kit
of
parts
in each
primary
station
and
each 30A
apparatus
unit
is required.
(g)
Supplementary
Alerting
Device
Access-The
operation
of
an
external
relay
to control bells, gongs, horns, etc, by incoming
ringing on CO/PBX lines
and/or
by depression
of
an
assigned DSS
button
is provided. This
feature
requires installation
of
a 25A
apparatus
unit,
an
external
relay,
and
a signal
with
its
power source.
(h)
Paging-Voice
announcements can be made
over
109A
loudspeaker sets
or
a customer-owned
and
maintained
paging system.
The
latter
arrangement
requires
the
use of a
27
A
apparatus
unit
to provide proper interface
with
the
4A
System. Background music
may
be provided by
means
of
customer-provided music
and
a 33A
voice coupler (same source
and
coupler used
for
music-on-hold). The paging
path
is activated by
operation of a DSS
button
assigned to
this
feature. The 109A loudspeaker contains two
customer-accessible volume controlsfor
adjusting
background music and pagingvolume; background
music is automatically muted
during
paging.
ISS
2,
SECTION
518-45()..1
06
(i)
Preset
Intercom
Multiple
Voice
Signaling-Allows
any number of preselected
stations
and/or
paging
loudspeakers
to
be
voice-signaled simultaneously by means of a
designated DSS button. A 26A
apparatus
unit
is
required
for
this
feature.
Remember
that
a
DSS
code
used
for
supplementary
signaling,
paging,
or
preset
intercom
signaling
is
no
longer
available
as
a
station
code.
(j)
Code
Busy
DSS
Key-Lamps
i:n
the
DSS
key indicate
'that
one ormore stations assigned
to
a DSScode
are
off-hook
or
beingvoice-signaled.
This
feature
can be implemented on a per-station
basis by replacing
the
factory-installed DSS key
with
an
identical size
664C
key which contains
LEDs.
Note:
In
systems where 980-series sets
are
mixed with 830-series sets,
the
664C
~·
will
indicate busy 980 sets only.
(k)
Power
Failure
Ringing-The
24B
a~tus
unit
(24A
in
early
installations) provides
two
C4B
ringers
and
associated circuitry to
connect
the
ringers
to
the
CO/PBX lines!:lin
the
event ac power to
the
4A Systemfails. Inst;eilation
of
a
24B
for each
primary
station
is·:recttrlred.
.
10?
(l)
Hands-Free
Answermg
on
I._lllf!ltun-
HFAI
is available only
as
a
built-in.feature
of
two 4A telephones (983A02
and
~-~
It
allows incoming intercom calls
to
be
·~red
without
any
manual
action by
the
c&llil
,_.ty,
whose microphone is
turned
on
by
•
4~oming
call. The
HF
AI
station
user
can operate a
"mike-off"
button
to disable
the
~ophone
while still receiving voice signaling
or
use a
"do-not-disturb"
button
to
both
disable
the
microphone
and
block voice signaling;
(m)
Speakerphone-Speakerphone··
~ice
permits
hands-free conversations on
<Je/PBX
and
intercom lines
and
is available itr·
the
4A
System
in
two configurations only: ·
·.r;;
(1)
Built-in
speakerphone
telephotw
sets
(983A01
and
2983A01).
(2)
An
external 4A speakerphone oonnected
to
the
HF
AI telephone set.
The~llatio:h
of
a D-180732 relay
kit
of
parts
is
r..,ect.
l
i.
I

SECTION
518-450-106
The
4A
speakerphone cannot be used with
anyother
4A
Communication System telephone
sets.
In
all
telephones
with
speakerphone,
the ability to bridge the
set
loudspeaker
across
the
iucomiug
line
with
the
SPKR
button
is
disabled.
(n)
Repertory
Dialing-This
feature
is
provided by connection of
an
870Al (rotary)
or 2870Al (TOUCH-TONE) adjunct repertory dial
with
DlOY-50
cord to desk models of satellite
telephone sets.
It
allows numbers stored
in
the
dial memory to be called by
the
operation of a
single button.
(o)
Supplementary
Power-A
19B2
power
unit
can be used to increase
the
basic power
capacity of
the
4A
System and to compensate
for
the
additional power required for
HF
AI sets,
code
busyDSS keys, and
109A
pagingloudspeakers.
If
any of these optional features are employed
in
the
4A
System, supplementary power may be
required.
Note:
The
19B2
power
unit
supplies only
24V
battery to
the
4A
System. The built-in
power supplies in
the
primary sets continue
to provide lamp power to
the
system and
control circuit power to the
primary
sets when
a
19B2
is connected.
(p)
External
RiDging-This
feature is provided
by connecting
an
external ringer (such as
an
ElC) across
the
CO/PBX tip
and
ring leads
at
the
primary station.
TELEPHONE
SETS
2.04
The 980-series telephone sets
are
completely
new in design; all components
are
connected
by means of plugs and jacks for quick assembly
and replacement. Primary and basic satellite sets
are
packaged in housings of
the
same width,
but
the
primary sets are somewhat deeper because of
the
control and power circuitry they contain.· BIS
and
HF
AI satellite sets require a wider housing to
accommodate
their
additional features.
2.05
The basic features described in
2.02
appear
in all sets. The
663A2
line key contains
ten
buttons-hold,
four common CO/PBX lines,
an
optional personal line, two intercom paths,
an
Page
10
optional privacy release, and built-in loudspeaker
on/
off control. LED
status
lamps
are
associated
with each line and intercom
path
button. The
664B
DSS key consists of two horizontal rows of five
buttons, each of which may be assigned to one or
more stations, a paging loudspeaker, supplementary
ringing
or
preset multiple signaling. Between
the
two rows of DSS buttons and under a hinged cover
are
the
pr9gramming
switches
for
DSS code
assignment
and
CO/PBX line ringing control. The
built-in loudspeaker is located under
the
handset,
and
its
volume control is below and to
the
right
of
the
dial. The recall (R) key is below and to
the
left of
the
dial. All sets employ
the
KlC
modular handset. The
rotary
dial is standard,
but
TOUCH-TONE is available.
2.06
The internal arrangement of
the
telephones
is based on
the
use of a molded plastic
chassis to which
the
components of
the
set
are
attached and
an
electrical interconnect field into
which
the
components are plugged (Fig.
5).
The
interconnectfield also contains positions for plugging
in optional features and switches A through H for
adapting
the
set
to options. Outside connections
are made by way of
the
set
mounting cord
or
separate cords for such optional features
as
personal
lines,
4A
speakerphone,
and
repertory dialing. In
primary sets (Fig. 6),
the
mounting cord plugs
'into
a wiring harness which distributes leads to
the
line
key and
the
control logic board. In
the
cit~r
desk-type sets,
the
mounting cord plugs directly
into
the
line key. ·The system connector cable is
intended to be plugged directly into
the
wali
~ets
without
the
use of mounting cords, which are' not
supplied with wall sets.
2.07
Mounted on the base of each primary
set
is
a logic board co)ltaining control and power
circuitry for two CO/PBX lines and one intercom
path, and a transformer for supplying ac
pow~r
to
the logic board (Fig.
6).
Up to seven satellite
telephones can derive
their
power from one primary
set. Each primary
set
contains a polarity guard
circuit which prevents
battery
reversals on
the
CO/PBX lines from interfering with TOUCH-TONE
dial operation
and
multiline conferencing.
PBX
INTERFACE
2.08
The
4A
System will interface with all PBXs
except
that
it
cannot provide for ground-start
operation of
CO
trunks which bypass
the
PBX
in
the event of PBX power failure. In all
other

UPPER HOUSING
WITH CHASSIS
PERSONAL
LINE
CORD
AMPLIFIER
IS
S 2, S
EC
TI
ON
518-4
50
-1
06
TRANSFORMER
LOWER HOUSING WITH
BASE AND
LOG
IC ASSEMB
LY
Fig
. 6- Primary
Set
Disassembled
respects, the system performs on PBX
li
nes in
th
e
sa
me manner as on
CO
lines. For PBX use,
the
only restriction on the number of
te
lephone
sets is
that
each 25-
pair
connector cable system
can ser
ve
a maximum of 2
primar
y
stat
ions and
14 satellite stations. Although
4A
telephone
sets
behind a
PBX
have full capabilities, they can contact
telephones in
ot
her systems only via PBX lines.
To signal the PBX ope
rator
,
the
recall button
must
be used.
ORDERING GUIDE
A. Basic
Apparatus
2.
09
Se
ts,
Telephone
Note:
Sets are supplied in ivory only and
are
shipped with E-6
723
ke
y designation
tabs
and disposable facepl
ates
. Order
the
desired
permanent facepla
te
s separately.
(a)
Prim
ary
Sets-Ord
er one for a system
with one or two
CO
/PBX lines and one
intercom
path
; order two for a
system
with three
or four
CO
/PBX lines and two intercom
pat
h
s.
• 981A01 (desk
mo
del, r
otary
dial; includes
D50AB-50 mounting cord)
•
2981A01
(desk model,
TO
UCH-TONE; in
cl
udes
D50AB-50 moun
ti
ng cord).
(b)
S
ate
llit
e
Sets-Ord
er
as
required.
(1
) Basic
Sat
ellite
Desk
Sets:
• 981A02 (desk model,
rotary
dial; includes
D50AW-
50
mounting cord)
•
2981A02
(desk model, TOUCH-TONE; includes
D50AW
-50
mounting cord).
Page
11

SECTION
518-450..106
(2) Basic Satellite
Wall
Sets:
•
981A03
(wall model, rotary dial; mounting
cord not included)
•
298.1A03
(wall model,
TOUCH-TONE;
mounting
cord not included).
(3)
BIS
Satellite. Sets:
•
983A01
(desk model, rotary dial; includes
D50A
W
-50
mountingcord,
D8W
-50
speakerphone
power cord,
2012B
transformer,
and
86A
connecting block)
•
2983A01
(desk model, TOUCH-TONE; includes
D50A
W
-50
mountingcord,
D8W
-50
speakerphone
power cord,
2012B
transformer, and
86A
connecting block).
Note:
Desk model of
BISset
can be.converted
to wall set by use of
kit
of
parts
listed in
2.10.
(4)
HFAI
Satellite Sets:
Keep
in
mind
when
ordering
HFAI
sets
that
each one consumes
as
much
power
as
any
other
two
statons;
therefore,
either
the
total
number
of
stations
in
the
system
may
have
to
be
reduced
or
supplementary
power
used.
See
3.06.
•
983A02
(desk model, rotary dial; includes
D50A
W
-50
mounting cord)
•
2983A02
(desk model, TOUCH-TONE; includes
D50AW-50
mounting cord).
Note:
Desk model of
HF
AI
set
can be
converted to wall set by use of kit of
parts
listed in
2.10.
2.10
Order
the
following as required depending
on the types of telephones being installed:
• Block, Connecting,
91A
(order one for each
primary station)
• Faceplate,
61C-*
(for 981-type sets)
• Faceplate,
261C-*
(for 2981-type sets)
• Faceplate,
63D-*
(for 983-type sets)
Page 12
• Faceplate,
263D-*
(for 2983-type sets)
*Add color code suffix
as
follows:
Avocado
-100
Teak
-108
Walnut
-109
Gold
-111
Orange
-112
Brown
-113
Red
-114
Blue
-115
Black
-118
• Kit
of
Parts,
D-180747
(order one for each
BIS
or
HF
AI satellite setto be wall-mounted).
•
•Kit
of
Parts,
F-60591 (order one for each
system
where
the
primary
sets
were
manufactured prior to August
1977
and
the
installation
environment
is
expected
to
produce severe static discharges; see
3.13)
.•
2.
11
Order
the
following
as
needed depending on
the
job wiring requirements (refer to Fig. 7
and 8 for typical connection arrangements):
• Adapter, Bridging, KS-19252,L1
• Backboard,
184B2
(includes four
66B4-25
connecting blocks)
• Block, Connecting, 66E3-25
• Cable, Connector, A25B (specify desired
length; single-ended)
• Cable, Connector, A25D (specify desired
length; single-ended)
• Cable, Connector, B25A (specify desired
length; double-ended)
• Cord, Mounting, D50AB-50
(7
feet
or
18
feet; extension mounting cord)
B.
Optional Apparatus
2.12
The following optional apparatus may be
ordered as required (see Table
B):
(a)
Personal
Line:
• Kit of
Parts,
D-180758
(consists of
86A
connectingblock,
D8W
-50
cord, jackassembly,
(
(
(
(

(
(
(
(
PRIMARY
* t
STATION
I I I
(NOTE 1)
00 00
[~
TO
CO/PBX
T2, R2
91A
APPARATUS
CONN BLK (NOTE 4 )
UN IT {NOTE 2)
p
*
**
TELEPHONE SET MOUNTING CORO
K5-19252, L1 {C-P-C)
109A
LOUD-
BGM
t
NO
1
2
4
5
BRIDGING ADAPTER
SPEAKER
B25A CONN. CABLE
MOH
(DOUBlE -ENDED)
TO CUSTOI£R
HA
PROVIDED -
VOICE
MIJSIC SOURCE
COUPLER
TES:
• PRIMARY STATIONS CAN BE BRIDGED IN ANYWHERE
IN SYSTEM IF
CABLE LENGTH DOES NOT EXCEED LIMITATIONS IN TABLE C•
•
24A OR B, 25A, 26A, OR 27A APPARATUS UNITS CAN BE INSERTED
ANYWHERE IN SYSTEM AS REQUIRED.
• 66E~-25 BLOCK AND A25B S1 NGLE-ENOED CABLES CAN BE USED
INSTEAD OF K5-19252 ADAPTERS IF DESIRED.
• EACH PRIMARY STATION MUST BE
r
91A
CONNECTED BY WAY OF 91A CONN BLOCK.
'"'"0' '""'.
• SYSTEM MAY HAVE UP TO 16 STATIONS,
TO
BUT OSS Ll NES MUST BE SHARED WHEN
CO/PBX ....ll.....!!!
THERE ARE MORE THAN 10 STATIONS.
PRIMARY
* t
STATION
(NOTE 1)
** I
P - PAGING
DQD
BGM - BACKGROUND MUS IC
MOH - MUSIC ON HOLD
66£3-25
'~Q'
SATELLITE
*
A25B CONN. CABLE I
STATION
I
A25D CONN. CABLE.,-
**
BGM
000
274A-
ADAPTER
109A
LOUD-
I
SPEAKER
r" ,
HEADSET
p
91A
CONN BLK
000
APPARATUS
Q0
UNIT (NOTE 2)
0D I I
t
I t
ISS 2, SECTION 518-450-106
t
TO
T R (PERSO~ L ltE)
-
CO/PBX
000 'OA
APPARATUS
UNIT
I
_u *
'""-"" i[
86A
r -
STATION
CONN BLK
noo D8W-50
CORO
r-:
*
SATELLITE
STATION
000
r:
*
SATELLITE
STATION
0 BIS
t t *
WALL
-STAr
ION
0 0
t *
HFAI
4A
-
SPEAKER-
STATION
1-
AIM
000
t *
HFAI
STATION
t
SATELLITE
WALL
STATION
t SATELLITE
WALL
STATION
Fig. 7 -·Typical Installation Using Bridging Connection MethocM
Page 13

SECTION
518-450-106
<
T,
R
(PERSONAL
Ll
1'£)
~OA
H
86A I
08W-50
CORD
TO
CO/PSX
APPARATUS
**
UNIT
CONN
BlOCK
I I
(
*
PRIMARY
STATION
-
I
(NOTE
1)
I
(T1,
R1
0
I
TO
CO/PBX
.~
HA
TO
DD
VOICE
-
CUSTOI£R
PROV
I
OEO
1109A
f
91A
CONN
BLK
COUPLER
MUSIC
SOURCE
LOUDSPEAKER
(NOTE
4)
(
APPARATUS
L
BGM
UNIT
(NOTE
2)
B25A
CONN
CABLE
I
SATELLITE
*
I
STATION
MOH
109A
STATION
WIRE
(+V,
COli,
DSS)
p
LOUDSPEAKER
**
I * SATElliTE
I
STATION
-
HAFI
l
*
L
STATION
**
HAFI
I
*
I
STATION
-
* BIS
I
I
STATION
**
BIS
I
*
STATION
-I
I I l
D D *
PRIMARY
["·~
109A
STATION
TO
p
lOUO
(NOTE
1)
CO/PSX
T4
R4
SPEAKER
.....!........;
91A
CONN
BLK
(NOTE
4)
**
HAFI
I
*
l
STATION
-
I
*
HFAI
I
STATION
P -
PAGING
BGM.-
BACKGROUND
MUSIC
MOH
-
MUSIC
ON
HOLD
"
f"
0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0
SIG
GRD
0 0 0 0 0 0 0 0 0 0 0 0 0
39
19B2
-0 0
040
POWER
UNIT
--
24VOC
0
0
0 0 0 0 0 0 0
0 0
0 0
0 8
SIG
0
0
0
0 0 0
0 0
0
0 0
0 0 0
0
0
0
0
0 0 0 0
0
0
0
0 0 0
*
TELEPHONE
SET
MOUNT
I
NG
....
....
....
CORD
P/0 6684-25 P/0 6684-25 P/0 6684-25
**
A258
CONN
CABLE
CONN
BlOCK
CONN
BLOCK
CONN
BLOCK
(S
I
NGLE-ENOED)
(
STRAPS
STRAPS
SEE
NOTES
1,
2,
4,
AND
5
18482
BACK
BOARD
OF
FIG.
7.
Fig.
8-.Typical
Installation Using "Home
Run"
Connection
Meth~
Page 14

(
(
(
plug retainer, and mounting bracket; order
one for each primary, basic satellite, or
HF AI satellite set to be equipped with a
personal line; do not order
for BIS satellite
set to be equipped with a personal line)
• Unit, Apparatus, 30A (order one for each
personal line
to be installed; includes 95B1
power unit).
(b) Music-on-Hold:
• Coupler, Voice, 33A (order only one per
system when music-on-hold is provided
and/ or when background music is provided
on paging system)
•
Kit of Parts, D-180730 (order one for each
primary station and each personal line to
be equipped with music-on-hold).
(c) Tone-on-Hold:
• Kit of Parts, D-180731 (tone-on-hold circuit
board; order one for each
primary station
and each personal line to be equipped).
(d) Paging:
• Set, Loudspeaker, 109A t(order quantity
required for paging and background music;
includes wall mounting
bracket with 85A
connecting block attached, D8W cord,
and
four rubber washers~
Each 109A loudspeaker consumes as
much power as a primary, basic sateBite,
or BIS set. Refer to 3.06.
• tcoupler, Voice, 33A (one is required for
background music on any paging system;
can be same one used for music-on-hold)t
• Unit, Apparatus, 27A (order one for interface
between 4A System
and a customer-owned
and maintained [COAM] paging system)
Note: The 27A will not drive COAM speakers
directly.
• Relay, KS-16626,L12 (order one for use
with
COAM paging system that requires a contact
closure).
ISS 2, SECTION 518-450-1 06
(e) External 4A Speakerphone (order one of
each of
the following for each HF AI station
to be equipped):
• Adapter,
223C (includes D16H-50 cord and
M2FG cord)
•
Kit of Parts, D-180732 (includes relay board
and button stop for SPKR button)
• Kit of Parts, D-180508 (provides ivory housing
for loudspeaker and ivory
trim for transmitter)
• Loudspeaker, 108A (any color)
•
Transmitter, 680A (any color)
• Unit, Power, 85B1-49.
(f) Supplementary Power:
• Unit, Power, 19B2 (order one if the power
requirements of
the system being installed
exceed
the capacity of the built-in power
supplies in
the primary sets; refer to 3.07
for details
of calculatingpower requirements)
• Cord, Power (order one of required
length
for 19B2 power unit):
824013262 (P-40J326)--1-1/2
feet
824013270 (P-40J327)--2 feet
824013288 (P-40J328)--4 feet
824013296 (P-40J329)--6 feet
824010995 (P-40J099)--12 feet
(g) Supplementary Alerting:
• Relay Set, KS-16626,L12 or Relay, KS-16302,L17
(order one for use with 25A apparatus unit
to operate an auxiliary signal)
• Unit, Apparatus, 25A
(order one for each
supplementary signaling device to be
operated).
(h) Repertory Dialing:
• Dial, Repertory, Adjunct, 870A1 (rotary) or
2870 1 (TOUCH-TONE) (order one for each
desk- satellite
station to be equipped
for reperto dialing)
Page 15

SECTION 518-450-106
• Cord, D10Y-50 (order one for connecting dial
to telephone; 2 feet long)
• Unit, Power, 95B1 (order one for each
repertory dial).
(i) Code Busy Indication:
• Key, 664C (code busy DSS key; order one
for each station to be equipped for busy
status indication; includes E-6873 key
de3ignation tabs)
Each 664C key consumes as much
power as a primary, basic satellite, or
BIS set.
(j) Privacy:
• Kit of Parts, D-180729 (privacy circuit board;
order one for each station to
be locked out)
(k) External Ringing:
• Ringer, E1C (order up to three for each
CO/PBX line to be equipped with external
ringing but no more than two if power
failure ringing is provided)
(1) Power Failure Ringing:
• Unit, Apparatus, •24B• (order one for each
primary
set to be provided with power
failure ringing)
(m) Preset Multiple Voice Signaling:
• Unit, Apparatus, 26A (order one for each
preset intercom voice signaling arrangement
to be installed) .
C. Replaceable Components
2.13 All Sets:
• Amplifier, 841009103
• Assembly, Dia.l, Rotary, 841010770 (includes
STA-119 dial)
• Assembly, Dial, TOUCH-TONE,
841010762
(includes 35AU3A dial)
Page 16
• Assembly, Loudspeaker, 841009053
• Connectors, 963E-2 (shorting bars for
interconnect field)
• Cord, H4DU-50 (handset cord)
• Form, E-6723 (key designation tabs for line
keys and
standard DSS keys)
• Form, E-6873 (key designation tabs for code
busy DSS keys)
• Handset,
K1C-50
• Jack, 616JK (handset jack)
• Key, 663A2 (line key)
• Key, 664B (DSS key)
• Key,
683C (recall key)
• Potentiometer, 841009061 (loudspeaker volume
control).
2.14 Primary Sets:
• Assembly, Base andLogic, 841009087 (includes
base, control logic board, and wiringharness)
• Assembly, Field, Interconnect,
841009954
• Cord, D50AB-50 (mounting cord)
• Housing, Upper, 61AU-50
• Housing, Lower,
61BL-50
• Transformer, KS-21361,L5 (includes 6-foot
power cord and heat sink).
2.15 Basic Satellite Sets:
• Assembly, Field, Interconnect, 841009954
(wall sets only)
• Assembly, Field, Interconnect, 841009988
(desk sets only)
• Cord,
D50AW-50 (mounting cord, desk sets
only)
• Housing, Lower, 61AL-50 (desk sets only)
(
(
(
(

• Housing, Upper, 61AU
-5
0
• Housing, Wall,
61A
Y
-50
(wall sets only).
2.16
BIS
Satellite
Sets:
• Assembly, Field, Interconnect,
8410
1
5449
• Circuit, Interface Signaling, Voice, 841010788
• Cord, D8W
-5
0
• Cord, D50AW
-50
• Housing, Lower, 63AL-50
• Housing, Upper, 63AU-50
• Transformer,
2012B
• Transmitter-Receiver,
1A
(BIS module)
2.17
HFAI
Satellite
Sets:
• Assembly, Field,
Int
erconnect, 841015050
• Cord, D50AW
-50
• Housing, Lower, 63AL-50
• Housing, Upper, 63AU-50
• Module,
HF
AI,
841010
796.
3. INSTALLATION AND CONNECTION
PLANNING
3.01 Consult with
the
customer to
determine
where
the
4A
System
stations
should be
installed, optional features desired,
the
best routes
for interconnecting cab
le
s,
intercom
code
assignments,
paging requirements, and the optimum locations
for connecting blocks,
apparatus
units, adapters,
etc.
•caution
:
Remind
the
customer
that
after
installation
has
been
finished,
primary
station
power
cords
must
remain
plugged
in
or
service
will
be
interrupted
.•
3.02
Either
the
bridging method of connecting
stations (Fig.
7)
or
the
"home-run" method
(Fig.
8)
can
be
used when
the
4A
System is powered
ISS
2, SECTION
518-450-106
entirely from
its
primary
sets.
However,
if
supplementary
power
from
a
19B2
unit
is
needed.
the
"home-run"
method
must
be
used.
Each
primary
station
must
be
connected
into
the
system
by
way
of
the
91A
connecting
block
(Fig.
9)
where
the
associated CO/PBX lines
are
terminated;
do
not
attempt
to
c
onn
ect
primary
sets
in
any
other
manner.
Satellite stations can
be
connected
through
KS-19252
bridging
adapters
or extension cables
with
66E3-25
blocks or a
184B2
backboard.
KS-16671,
LIO
PLUG
MOUNTING HOLES
Fig.
9-91A
Connecting
Block
3.03
Apparatus
units
24A
or
B through
27
A can
be mounted where
there
is convenient access
to system cabling. Each
unit
ha
s
input
and
output
connectors which
mate
with
the
system
cable
connectors, allowing
the
unit
to be
inserted
between
stations or
at
the
end of a cable run. Specific
Page
17

SECTION
518-450-106
instructions for the location of apparatus units and
other optional external equipment are included in
the installation instructions for particular features.
3.04
Select and order
the
appropriate apparatus
according
to
the
job
requirements
(see
ORDERING GUIDE).
POWER
REQUIREMENTS
3.05
The customer is responsible for providing
suitable
117V
60-Hz power outlets not under
control of switches for
the
following components
of the
4A
System installation: each primary set,
19B2
power unit, BIS station,
4A
speakerphone,
repertory dial, and
30A
apparatus unit.
Primary
sets and
the
19B2
power unit require a grounded
ac receptacle which is separately fused.
Except
for
the
117V
power
cords
and
the
33A
voice
coupler,
make
no
connection
between
any
point
in
the
system
and
building
ground.
Supplementary Power
3.06
Sufficientpower isavailable from
the
built-in
power supplies in
the
primary sets for most
4A
System installations. However, a concentration
of optional features (HFAI sets,
109A
loudspeakers,
code busy DSS keys) can make
it
necessary to
install a
19B2
power
unit
for supplementary power.
3.07
In
order todetermine whether supplementary
power is required, follow this procedure to
get
the
station
equivalent
number
of
the
installation:
(a) Calculate the values below based on the
particular equipment being installed: ·
(Number of non-HFAI sets, including primary
sets)
X
1 =
_.
(Number of HFAI sets)
X
2 =
_.
(Number of
664C
code busy DSS
keys·
in
excess of two per system)
X
1 =
_.
(Number of
109A
loudspeakers) X 1 =
_.
Sum =
_(station
equivalent number).
Page
18
(b)
If
the
system has one primary station
and
the
station equivalent number is
greater
than
8,
install a
19B2
power
unit
and use
the
"home-run" method of system connection.
tNote:
Refer to
3.30
for detailed installation
and
connection
instructions
for
the
19B2
power
unit
.•
(c)
If
the system has two
primary
stations and
the
station equivalent number is
greater
than
16,
install a
19B2
power
unit
and use
the
"home-run" method of system connection.
Example:
Installation has one primary set,
four basic satellite sets with code busy DSS
keys, two
HF
AI sets, one BIS set,
and
one
109A
loudspeaker. ·
6 X 1
=
6 (non-HFAI sets)
2 X 2 =
4
(HFAI sets)
2 X 1 = 2
(664C
keys)
1 X 1 = 1 (loudspeaker)
Sum=
13.
Therefore, a
19B2
power
unit
is required.
Supplementary
power
cannot
extend
the
system
capability
(either
1
or
2
primary
sets)
beyond
16
station
sets
or
32
station
equivalents.
CABUNG
RESTRICTIONS
3.08
Station
Interconnection-No
more
than
2000
running feet (total) of cable should be
used for connecting together
the
stations in any
installation.
In
installations where bridged cabling
is used (Fig.
7),
the
maximum distance between
any satellite station and both
primary
stations
or
between primary stations must not exceed
the
restrictions in Table
C.
In a small system where
only one primary station is required and bridged
cablingis used, the total number of station equivalents
must not exceed eight since supplementary power
cannot be used. When two primary sets
are
used
with bridged cabling,
the
limit is sixteen.
3.09
Personal
Line
Cabling-Personal
lines
do
not utilize the system interconnection
(
(
(
(
(

(
(
(
(
{
TABLEC
LIMITATIONS
ON
CABLE LENGTH
AND
SYSTEM SIZE
NUMBER
MAXIMUM
CABLE
FEET
FROM
OF
SATELLITES
TO
BOTH
STATION
PRIMARY
STATIONS*
EQUIVALENTS
10
or
less
1000
11
900
12
800
13
700
14
600
15
500
16
400
*Total number
of
feet in any installation
shall
not
exceed
2000
feet.
cables
but
require separate connections between
stationsand
30A
apparatusunits. Fig. 10 illustrates
the limitations on
the
connection of personal lines.
Bridged cabling can connect a maximum of
16
sets
to a
30A
apparatus unit. Refer
to
3.51
for detailed
instructions on installing personal lines.
SYSTEM
CABLING AND
CONNECTIONS
3.
1
0
Install
the
necessary connecting blocks,
bridging adapters,
apparatus
units,
and
backboard
at
the
desired locations and connect them
with appropriate connector cables. Use
the
shortest
possible lengths of cable consistent with
other
requirementsof the installation. Where single-ended
cables
are
used, cut them down on
the
connecting
blocks in standard color-code sequence (Table D).
TaEPHONE
SETS
3.11 Carefully unpack the telephone sets and
install them
at
the locations requested by
the customer. When placing desk-type telephones,
allow enough room adjacent to
the
sets for headset
adapters, repertorydials, and external speakerphones
if these options
are
to
be
installed.
Put
the
ISS
2,
SECTION
518-450-106
appropriate designation
tabs
in
the
buttons of
the
line
and
DSS keys.
N.ote:
Do
not install PRIV RLS
tabs
in
any
sets unless
at
least one
station
in
the
system
is equipped with
the
privacy feature. On BIS
satellite sets
•and
HF
AI sets to be equipped
with
4A
speakerphone,. do not install
the
SPKR tab;
this
button is inoperative.
Primary Sets
3.12
Place each primary
set
within power cord
length
(6
feet) of a suitable ac receptacle.
Do
not
plug
in
the
primary
station
power
cords
until
all
installation
is
complete.
Connect each
primary
set
into
the
system by
plugging the attached D50AB-50 mounting cord into
its assigned
91A
block.
3.13
•F-60591
Kit
of
Parts-This
kit
is a
resistor network used to provide additional
static
discharge protection. Install one resistor
network
as
shown in Fig. 9 on
the
91A
connecting
block of one primary telephone set
per
installation
if
either
of the following conditions exist:
(a) The installation is provided with hands-free
answering on intercom.
Note:
The F-60591
kit
is shipped loose with
the
HF
AI sets.
(b) The installation environment is expected to
produce severe static discharges, ie, very
dry carpeting through
the
area, etc.
3.
14
Primary
sets manufactured
or
repaired
after
July
1977
will have
an
equivalent static
protection added inside
the
set. Therefore,
if
any
primary
set
at
a given installation bears a
date
stamp
later
than
July
1977,
do
not install
the
F
-60591
kit
of
parts
.•
Basic Satellite
and
HFAI Desk Sets
3.15 Connect each set into
the
system with
the
attached
D50A
W
-50
mounting cord; plug
its
free end into· its assigned bridging adapter
or
extension cable.
Page
19

SECTION
518-450..106
SOA
APPARATUS
liiiT
PERSIIIAL
LirE
TEIIIWL
6ROlPS
(11
(2)
(3) (4)
CA
,
IIAXIIUI
4
STATIIIIS
BRIDGED
ACROSS
IDE-Rill
CABLE
TO
30A
~~-o+-~-4r+----~----~----~----~
LP
o+--+--o+--
1---++--
SAlE
AS
ABOVE
A
o+--+--o+--
t--1---+-1---
SAlE
AS
ABOVE
R
o+--+-4+--
t--+--+---+-+--
SAlE
AS
ABOVE
JliAXIIUI
CABLE
LErlnHS
Ill.
OF
SETS
MX.
CABLE
FEET
BRIDGED
PER
FRill
30A
TO
TEIIIINAL
FARTI£ST
IIROUP
STATION*
1 1800
2
BOO
3
500
4
400
*
TOTAL
CABLE
LENGTH
FRill
30A
TO
ALL
STATIONS
I'IJST
lilT
EXCEED
2000
FEET.
Fig. 1
0-Personal
Line
Cabling Limitations
BIS
Desk Sets
3.16
Connect each set into the system with
the
attached
D50A
W
-50
mounting cord; plug its
free end into its assigned bridging adapter or
extension cable. BIS satellite desk stations require
an
additional connection to provide power for the
built-in speakerphone. Mount the
86A
block (Fig.
11)
supplied with each BIS set in a convenient place
near
the station,
and
plug
the
D8W-50 cord
extending from the back of the set into it. Use
inside wire to connect terminals 7 and 8 of the
86A
block to the
2012B
transformer supplied with
the set.
Do
not
plug
the
2012B
into
an
ac
receptacle
until
all
installation
is
complete.
Basic Satellite Wall Sets
3.17
The wall model ofthe basic satellite telephone
is a separately coded set and is equipped
with a wall mounting plateand appropriate hardware.
It
is intended to be connected directly to a system
connector cable and is, therefore, not supplied with
a mounting cord.
Page
20
3.18
There are three basic methods of connecting
a wall set into the
system-(a),
(b), and
(c):
(a) A system cable can be
run
along the wall
surface to the location where the set is to
be mounted and connected directly to the
set
(Fig.
12)
..
(1)
Attach the wall mounting plate to the wall
using four
#8
screws. Place a spacer,
supplied with the set,
on
each screw so
that
the plate stands off from
the
wall.
(2)
If
the cable connector has a screw
at
the
end, remove and discard the screw.
(3)
Remove the connector mounting screw
(Fig.
13)
from
the
top of
the
connector
bracket
on
the wall plate and save for step
(6).
(The lower bracket screw is captive to
the bracket and should be left
in
place.)
(4)
Position thecable connector
on
the mounting
brackets with the flange on
its
outer end
between
the
stationary· upper bracket and
(
(