Rev. 11/10/00
33
8.
If the needle swings to the right, then falls to a position slightly above 50; a
load coil has been detected.
a.
The first coil detected is indicated by a large needle pulse.
b.
The second, third, and fourth coils are indicated by progressively
smaller needle pulses.
9.
The
Coil Detect
test automatically recycles and restarts the test when the
needle drops to near zero, then swings to the far right again.
Loop Current Test
The
Loop Current
test is an important indicator of resistance problems on a
line’s pair. Loop current is inversely proportional to resistance. Therefore, as
resistance
increases
, a pair’s loop current
decreases
and as loop current
increases
,
resistance
decreases
.
Procedure
1.
Turn the
MODE SWITCH
to
OFF/DIAL
.
2.
Connect test leads; Black, Red, and Green to; Tip, Ring, and Ground.
3.
For Tip-to-Ring
– Turn the
MODE SWITCH
to
LOOP CURRENT
to read the
current on the meter’s black scale.
4.
For Tip-to-Ground
– Toggle and hold the
TIP
SWITCH
in the
UP
position.
Then read the meter.
5.
For Ring-to-Ground
– Toggle and hold the
RING SWITCH
in the
UP
position. Then read the meter.
Note:
The Ring-to-Ground current should be at least 1 ½ times the Tip-to-
Ring loop current. Otherwise, there may be a ground fault at the C.O.
There should be no Tip-to-Ground current.
Loop Current: Measured in mA*
Scale:
0 to 100 mA
Acceptable:
23 mA and higher
Marginal:
20 to 23 mA
Unacceptable: below 20 mA
* Per Bellcore standards. Specific company or local standards may be different.
