When the test is complete, summary
Pass/Fail results will be shown, similar to
this example:
Any failures will be highlighted in flashing
reverse video. To see more information about
a test, highlight the test, and press the
Details key. For capacitive length and bal-
ance results, highlight Opens test results and
press Details soft key.
Passing results:
AC Voltage < 10V
DC Voltage < 3V
Resistive Faults > 150 kohms
Capacitive Balance > 95%
Capacitive Length < 15000 ft
Longitudinal Balance > 55 dB
Metallic Noise < 30 dBrn
Power Influence < 80 dBrn
Load Coils < 1
Loop Resistance and
Resistive Balance
Tests completed:
• Measure loop resistance and balance
• Convert to loop length
Set-Ups
• Open POTS Toolbox
• Highlight Shorts and Grounds test
• Press Setups key
• Set cable gauge and estimated
temperature
• Press the BACK key to return to the POTS
Toolbox
• Using supplied strapping cord, short the
far end of the pair to ground (tip and ring
shorted together and to ground)
• At the near (test) end of the pair, connect
the 990’s tip, ring and ground leads
• Highlight the Shorts and Grounds test (in
POTS Toolbox) and press the TEST key
When the test is complete, results similar to
this example will be shown:
Verify that the tip ground and ring ground
resistances are within three ohms of one
another.
Use the Ohms to Distance function to calcu-
late pair length, shown here:
Bridgetap Detection
Tests completed:
• Identify bridge taps
• Determine number, length and distance
from subscriber
Set-Ups
• Turn on set
• Highlight TDR Auto-Test and press Setups
soft key
• Set cable gauge and type being tested
• Adjust VOP (Velocity of Propagation) as
needed. For more information, see Section
6 of the Users Guide
• Press BACK key to return to the main
menu
• Connect tip, ring and ground test leads to
the pair
• Highlight TDR Auto-Test and press TEST
When the test is complete, results similar to
this example will be shown.
If bridge taps are detected, use Cursor 1 and
Cursor to determine length and location.
Pass/fail limits:
Total bridge taps <3
Max length of longest < 2000 ft
Max length of all bridge taps < 2500 ft
Min distance from subscriber > 1000 ft
