1
15
15.2
Identify Split Conductor of Line #1.
a.
Remove the strap from line #1 at the near end.
b.
Connect one test clip to the split conductor of line #2 (identified in Paragraph
15.1, step f.).
c.
Connect the other test clip first to one conductor of line #1 and then the other
conductor. The conductor that does not cause a deflection of the meter is the
split conductor of line #1.
16.
TEST FOR VOLTAGE
a.
Open line in trouble to-
ward Central Office.
b.
Set the Instrument to mea-
sure voltage (ON/OFF
switch to OFF).
c.
Connect one test clip to
ground*.
*GROUND: A connection to
metallic cable sheath or wrap,
to cable suspension strand, to
ground rod, or to grounded (T)
conductor of an adjacent pair.
d.
Connect the other test clip to one conductor and then to the other. If the meter
deflects to the left of zero, the polarity is incorrect. Set the REVERSE switch to
its other position to obtain an up-scale reading.
e.
The meter will indicate the value of any DC voltage that may be present on a
line conductor (with respect to ground) or, by connecting the clips to both
conductors, any voltage present across the line. (100 POINTS = 100 volts).
NOTE:
The Instrument will not indicate the presence of AC voltage.
f.
When the REVERSE switch is in the normal position (opposite to the RE-
VERSE position) and the meter deflects upscale, the polarity of the voltage is
positive (+) at the red test lead if the leads have been connected to the
Instrument properly (refer to page 8, Section 5, step b.).
17.
CALCULATING DISTANCE TO FAULT
a.
Open conductors toward
Central Office.
b.
Set the Instrument to
measure resistance
(ON/OFF switch to ON;
“Press for Ohms” de-
pressed, 8455A).
c.
Short test clips together
and adjust BATTERY
ADJUSTMENT control
for meter reading of full
scale (100 POINTS).
d.
Connect one test clip to each conductor. The resistance value indicated is the
CONDUCTORS OPENED FOR TEST
R
T
FAULT
R
T
TO
STATION
TO
CENTRAL
OFFICE
8455
GROUND
*
LINE IN TROUBLE
OFF
CONDUCTORS OPENED FOR TEST
R
T
FAULT
R
T
TO
STATION
TO
CENTRAL
OFFICE
ON
8455
LOOP RESISTANCE
Figure 17-1. Calculating Distance to Fault
Figure 16-1. Test for Voltage
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