Bell system Ks-8455 Operating and installation instructions

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

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

(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

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.

Bell System KS-8455 Operating and installation instructions

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