Bell System Practices 2682 Service Manual page 4

SECTfON 502-612-425
Brown (Line 4), Slate (Line b, Cutoff
Key,
or
Transmitter), and White (Line
6).
2.O4
Sets
may
be
equipped
for internal
speakerphone
by the addition
of
a 679A (MD) transmitter
in
the 3rd
(2682AA)
or 5th
(268g4A)
module.
Figure 5
and Table
B
show
wiring of
sets with
speakerphone when
transmitter is internal fusing
a 55-type (MD) control
unit.{
Note:
In
addition
to
any normal
conversion
for
speakerphone S
coded sets
must
have the
two (G) TIP
leads on terminal
(l)
moved to
terminal
12.
On 3-type (MD)
speakerphone
applications
only,
the
insulated and
stored
(BL-Y) lead must be
connected
to terminal
13
of terminal
board.
2.OS
To add
speakerphone
to
telephone
sets
equipped
for
4-wire
service,
a
modified
55B
(MD) control unit
and
J53041D,
Ll
control unit
must be provided. Refer
to
Section
512-620-487.
Caution: Howling may result it
speakerphone
is turned on
while
headset
is
plugged
in.
2.06
To retain the maximum number
of
keys in
these
CALL DIRECTOR
telephone sets
and
still
have speakerphone feature,
a
666A
(MD)
or
6668
(MD) transmitter and 760A (MD)
loudspeaker
may be installed as adjuncts to the
telephone
set.
Spare leads
from the
first
module are
used
to
supply the external
speakerphone
function (Table
C).
Refer
to
Section
512-620-450
for
complete
connections
to
speakerphone.
2.o7 )A
4A
speakerphone system
can also
be
connected tothe2682-
and 2683-type telephone
sets.
Refer
to
Section
512-730-460
for
both
2-
and/or 4-wire station
connections.{
2.08
All
line pickup key positions
are-convertible
to signaling
or common signaling arrangements
by removing the
812857738
(P-288773) detail from
key positions involved and making
the
necessary
wiring
changes
per Table
D.
2.O9
The
2682-
and 2683-type telephone sets
are
factory-equipped
with
a KS-20419L1 (10 volt
ac only) buzzer.
2.1O
)The hold key
in
the
first
module
is
used
for
normal hold functions or
if
required
I
Poge
2
Hold,
An additional
hold key can be installed in
the
second key module location for
Priority
HoId.
The
D-180411
Kit
of Parts
consisting
of
a
6B5A5C
key, two contact
strip
assemblies, and
a pink
plug
assembly must be ordered separately
for
Priority
HoId.
(a) Install
as follows.
(1)
Unplug and
remove existing
6B5G5C
key
from
second module.
(2)
Install
contact
strips
and
associated leads
if
applicable (see
note).
Note:
Contact strips are not
required with
sets
equipped
with
a
D120M
or
D200AA
mounting
cord or
sets equipped
with
a
modified
D120K
or
D200S
mounting
cord.
(3)
Place
the pink plug
assembly
from
the
kit
of parts into the hold
position on the
635A5C
key.
Insulate and store the white
set
plug.
Place remaining set plugs into their
proper positions on
the
key.
(4)
Make
the
necessary
wiring
connections
and modifications as shown
in
Fig.
6.{
2.11
Station busy lamp is furnished in
these
sets
as follows:
o
If
all
modules
are
equipped
with
keys,
a
D-180463
Kit
of
Parts
consisting of
a 819040388
(P-90D033) Printed Wiring Board
Assembly
and
840361836
plug
assembly
must
be
ordered. The plug
assembly
is
used
to
provide the
chaining function
for
the
last
key module (option X, Fig.
?).
o
If
all
modules
are not
equipped
with
keys,
only the
819040338
(P-90D033) Printed Wiring
Board Assembly is required.
The (O)
lead
is
connected
to
the
same terminal as
the
(G-V) chaining lead of the
last
equipped
module (option
Y, Fig.
7).
2.12
When
a
polarity
guard is required
with
these
sets,
install
a
819041971
(P-90D197)
(MD)
or
840364376
guard assembly as shown
in
Table
E.
Polarity guards should be installed only
when
authorized
by
local instructions
to
eliminate
the
affect of battery and ground reversals
encountered
in
end-to-end signaling.