Tempo Communications 1155-5003, Instruction Manual

Page: 22 / 108

22
Sidekick
®
Plus Test Set
Measuring Loop Current
Loop current is inversely proportional to resistance. If a
pair’s loop resistance increases, its current decreases.
Measuring the loop current, therefore, provides an
important indicator if there are any resistance problems
on an active pair.
To measure loop current, perform the following steps:
1. Connect the test leads: black to tip, red to ring, and
green to ground.
2. Move the rotary knob to the VOLTS position and
press Fn .
Note: The ring-to-ground current should be at least 1.5
times the tip-to-ring loop current. If it is not, there may
be a ground fault at the central office. There should be
no tip-to-ground current.
The following is a guideline for pair performance for
DC current:
• Scale: 0 to 110 mA
• Acceptable: 23 mA and higher*
• Marginal: 20 to 23 mA
• Unacceptable: below 20 mA
*per Bellcore/Telcordia standards; specific company or
local standards may be different.
A single pair measurement appears on the LCD screen.
To change the single pair measured or make another
choice, use the following function keys:
•
F1 T-G displays tip-to-ground; “T-G” now in the
upper left corner and “T-G” button is highlighted.
To return to tip-to-ring, press F1 again.
• F2 R-G displays ring-to-ground; “R-G” now in the
upper left corner and “R-G” button is highlighted.
To return to tip-to-ring, press F2 again.
• F3 3-Lead accesses the 3-lead screen.
• F4 AC toggles between AC and DC. “AC” is high-
lighted when the AC measurement is primary.
To exit the LOOP CURRENT function, move the rotary
knob to any other position.