Bell System KS-8455 Operating and installation instructions
© Jeff Lamb TCI Library: www.telephonecollectors.info
BELL
SYSTEM
PRACTICES
SECTION 106-020-1
OOCA
Issue
C,
July, 1972
Bell
Canada
Standard
KS-8455
TEST
SET
DESCRIPTION
AND
USE
CONTENTS
1. GENERAL
2. DESCRIPTION OF
TEST
SET
3. INSULATION
RESISTANCE
MEASUREMENTS
4.
GROUNDS
5. SHORT CIRCUITS
AND
CROSSES
6.
BALLISTIC
TESTS
PAGE
243
243
244
244
244
245
7. VOLTMETER
TESTS
245
8.
STRAPPED
SLEEVE
METHOD OF TESTING
IN
COMMUNITY
DIAL
OFFICES
245
9. MAINTENANCE OF
TEST
SET
246
1. .GENERAL
1.01
This
section covers
the
description, oper-
ation
and
u
se
of
the
KS-8455
Test
Set
used
primarily
to
loc
ate
troubles
in
distribution
plant
in
unattended
switching
centre
areas.
This
section
is reissued
to
update
general
information.
1.
02
This
set
can also be used
to
advantage
in
other
switching
centre
areas
such
as:
-where access to local
test
desk facilities
is difficult
as
may
be
the
case when
large
P.B.X. installations
are
remotely
located;
-
where
the
test
desk cannot be reached
readily because
of
the
type
of equip-
ment
or
volume of
traffic;
-
where
the
test
desk cannot be reached
because
of
defective
plant
conditions
as
may
exist
in
floods
or
storms.
1.
03
In
loca
ting
high resistance
joints
in wires,
and
in
testing
station
grounds
and
ot
her
low resistances
it
will be found necessary
to
use
the
MD-661X
Test
Set
instead
of
the
KS-8455
Test
Set. (See
appropriate
section
in
Division
106.)
2.
DESCRIPTION OF
TEST
SET
2.
01
The
test
set
and
leat
her
carr
y
ing
case
are
illustrated
below:
KS-8455
Test
Set
The
KS-8455
Test
Set
is
made
up
of
the
following
parts
:
(a)
KS-8455
Test
Set,
List
1 - Complete s
et
except
battery
(b)
KS-8455
Test
Set,
List
2 - Volt-Ohm-
meter
only
(c) KS-8456
Carrying
Case
(d)
WlAH
Cord
(e)
NS-14369
Dry
Battery
2.
02
The
test
set
circuit consists essentially
of
a
microammeter, resistances, 45 volt
battery,
©Bell Canada, 1972
Printed
in
C
anad
a
243
TCI Library: www.telephonecollectors.info © Jeff Lamb
SECTION 106-020-1
OOCA
and switches which
permit
setting
up
the
tool
either
as
an
ohmmeter
or
a voltmeter.
With
the
ON
and
OFF
sw
it
ch on
the
ON position
the
tool
is
an
ohmmeter
and
on
OFF
position it
becom"!s
a voltmeter.
7.03
The
ohmmeter circuit
is
used
for:
(a)
Determining insulation resistance
of
a
line, between
wires
or
between one
wire
and
ground.
(b) Making ballistic
te
sts
to
detect opens
or
to
check bridged condenser connections.
The
meter
scale
is
calibrated
to
re
ad insulation
resistance directly
in
ohms, megohms,
or
"points"
which correspond approximately
to
the
"points"
reading
obtained on
the
voltmeter
in
the
No. 2
Test
Cab
inet
usually provided in community dial
offices. The
range
of
the
ohmmeter is 0 to 2 meg-
ohms
with
the
(R
-:-10) key in
the
normal po-
sition;
with
this
key depressed
the
range
is 0
to
.2
megohms.
2.
04
The voltmeter circuit is used
primarily
for
me
asu
ring
line voltage
and
foreign
EMF
.
The
range
of
the
voltmeter is 0
to
100 volts.
3.
INSULATION
RESISTANCE
MEASUREMENTS
3.
01
Before
making
insulation resistance mea-
s
urement
s
adjust
the
set
as
follows:
(1)
Turn
ON-OFF switch
to
ON.
(2)
Short
circuit
the
two cords
by
clipping
them
together.
(3)
Turn
"Battery
Adju
st
men
t"
knob until
needle is
at
100 on
the
"points"
scale.
Rep
eat
this
adjustment
from time-to-time
to
compensate
for
any
change
that
may
occur in
the
battery
vo
lta
ge.
3.02
The
procedures
for
us
ing
the
KS-8455
Test
Set
to
lo
calize insulation
faults
are
th
e same
as
those recommended
in
Section 462-
800-500.
4. GROUNDS
4.01 To
test
for
a fault-to-ground proceed as
follows :
244
(1) Open
the
line
at
a convenient location such
as
at
a cable terminal
or
bridging
point.
(2) Connect one clip to ground. A suitable
ground connection
may
be secured
from
the
suspension
strand
or
other
associated
grounded plant,
from
the
grounded side of.
an
adjacent
line,
or
from
a temporarily driven
ground rod.
(3) Connect
the
other
clip to
the
wire
to
be
measured.
(4)
Throw
ON-OFF key
to
ON.
(
5)
Read
meter
deflection.
If
read
on
the
ohm
or
megohm scale,
the
reading
indicates
the
insulation
re
sist
ance of
the
measured
wire-to-
ground;
if
read
on
the
"points" scale,
the
in-
sulation resistance is obtained·
in
terms
of
points.
ADJACENT
LINE
TO
C.0. -1
II
I I
LINE
OPEN
PRIOR
TO
TEST
\
CABLE
~--
-----;.
SUSPENSION
~
,...
..........
GROUND
SIDE
TO
STATIONS
LINE
IN
TROUBLE
STRAND
,...
.....
ri-
,...,...
~
REV
.
KEY
IN
EITHER
POSITION
GROUND
ROD
OFF
·
ON
KEY
AT
ON
5.
SHORT
CIRCUITS
AND
CROSSES
5.
01
To
test
for
short
circuits between wires
of a
pair
or
a cross between
the
wires
of
different
pairs
the
proce
dure
is
the
same
as
in
Part
4,
exce
pt
that
the
clips shall be placed across
the
wires
und
er
t
est
as
shown in
the
following
diagrams.
(a)
Te
st
.
for
short.
LIN
E
OPENED
FOR
TEST
TOC.o.-
__
_ , -
"-----
-t-
--
-TO
STATION
SHORT
CORD
OFF-ON
KEY
AT
ON
© Jeff Lamb TCI Library: www.telephonecollectors.info
(b)
Test
for
cross.
TO
C.O.-
-To
STATION
LINE
OPEN
j
CROSS
OFF·ON
KEY
AT
ON
6.
BALLISTIC
TESTS
6.01 The KS-8455
Test
Set can be used
in
the
same
manner
as
the
office voltmeter
to
detect opens
or
the
presence of a condenser
on
the line. Methods
of
making
these
tests
are
indi-
cated by
the
following sketches.
(a)
Test
for
open on
an
individual line.
TO
C.O. -
LINE
OPENED
)
STATION
OFF
-
ON
KEY
AT
ON
OPERATE
REV
.
KEY
(b)
Test
for
open on a
party
line.
TO
C.O.
----
)
LINE
-
OPENED
Off.ON
KEY
AT
ON
(c) Ballistic
test
for
grounded
ringer
s.
TO
C.O.- j
LINE
OPENED
OFF
-
ON
KEY
AT
ON
6.
02
Having
made
the
connections illustrated
operate reverse (Rev.) key back
and
forth
slowly enough so
that
needle will
return
to
zero
at
the
end of each
swing
.
If
the
needle deflects
ISS.
C,
SECTION 106-020-lOOCA
off
the
scale, keep
the
R--:-10
key depressed while
operating
the
reverse key.
7. VOLTMETER
TESTS
7.01
To
use
the
KS-8455
Test
Set
as
a d-c volt-
meter, place
the
ON-OFF key
in
the
OFF
position. Connect
the
clips across
the
circuit
on
which
the
voltage is
to
be measured.
If
the
volt-
meter
reads
backwards operate
the
reverse key.
The reading on
the
points scale is
the
value
of
the
applied potential
in
volts.
7.
02
The
R
--:-
10
key should
not
be depressed
when
taking
voltmeter readings.
8.
STRAPPED
SLEEVE
METHOO OF TESTING
IN
COMMUNITY
DIAL
OFFICES
8.01
In
m
any
instances
testing
with
the
KS-
8455
Test
Set
may
be facilitated
by
utiliz-
ing
the
operation
of
the
cutoff relay which re-
moves
battery
an
d
ground
from
the
line
in
trouble. This
permits
tests to be made
at
various
locations on
the
line both
"ahead"
and
"towards"
the
central office,
and
allows
certain
tests
to
be
made on open
wire
sections
without
cutting
the
line. This
test
is
made
as
follows:
(1)
Tie
the
sleeve of a
spare
connector
ter-
minal to
the
sleeve of
the
connector
ter-
minal of
the
line in trouble
at
a common
appearance (location
of
the
common
appear-
ance
differs
in
different
types of offices).
The
strap
may
be removed
after
the
tests,
at
the
convenience of
the
tester,
as
no trouble will be
caused while
it
is in place in
the
office '
with
a
standard
strap
or
shu
nt
cord.
(2)
At
the
testing
location
of
the
line in
trouble, connect a dial
hand
test
set
to
an
adjacent
working line,
if
available,
and
dial
the
spare
connector terminal.
-
If
a busy signal
is
encountered,
it
is
an
in-
dication
that
the
line
to
be tested
is
busy
or
has
become permanent.
-
If
a
ringing
signal is
heard,
it
is
an
indica-
tion
that
the
cut-off relay
has
operated
and
the line
to
be tested is open
at
the
central
office.
As
long
as
the
connection
to
the
spare
connector terminal is held up
and
the
ring-
ing
signal is heard,
the
line
to
be tested will
remain
in
this
condition.
246
TCI Library: www.telephonecollectors.info © Jeff Lamb
SECTION
106-020-1
OOCA
(3)
If
an
adjacent line is not available for dial-
ing the spare connector terminal, and
if
the fault on the line in trouble is not of suf-
ficient value to interfere with dialing, use the
hand test
set
on the line in trouble
to
call the
test desk or operator
at
the master office. Have
the test
de
skman
or
operator dial the spare
connector terminal and hold the connection for
a prearranged length of time, say two minutes.
With the "Talk-Mon." key on the dial hand test
set
in
the monitoring position, the combination.
man
may monitor
on
the line while the test
deskman is placing the call. Evidence of the
operation, the cut-off relay will be a click in the
re
ceivei: of the hand
set
or
a change in the vol-
um
e
of
line noise.
(4)
After
the battery and ground ha
ve
been
removed from the line, proceed with the
desired tests.
8.
02
A typical application of this method of
testing is illustrated by the following
sketch.
246
AT
C.O.
HANO
DIAL
TEST
SET
CORO
REV
KEY
AT
EITHER
POSITION
.
9. MAINTENANCE
OF
TEST
SET
L
MOV
~
.
WIRE
AND
WATCH
METER
DEFLECTION
FOR
CHANGE.
9.01 Rea
so
nable care should
be
exercised in
handling the test set. The set should be
protected against unnecessary shocks
or
jars.
9.
02
The battery should
be
replaced when
it
is
impossible to
adjust
the meter needle to
100
on
the points scale by use of the battery
ad
-
ju
stment knob.
9.
03
To replace the b
attery
remove the s
et
from
the leather case. Remove the panel on the
back of the s
et
by taking out the four screws
which hold
it
in place. Disconne
ct
the old ba
tte
ry
from the terminals (snap fasteners) and replace
it
with a new one. The terminals
are
so arranged
that
it
is impossible to reverse the polarity.
