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Opens Fault Locator
or
Selects T-R or R-G or T-G
Setup capacitance factors
The opens function can be used to determine the distance to
both a “full” open as well as to a “partial” open. There are
three measurements provided – mutual length, tip length
and ring length. For a “full” open ( ie tip and ring are open
at the same place ) use the mutual reading. For a “tip”
open, use the tip length and for a “ring” open, use the ring
length.
The test begins by displaying the mutual in the center box.
Pressing
moves the ‘live’ reading to one of the other
boxes showing the ring length in the upper left box or the
tip length in the lower left box. The boxes not currently
‘live’ retain their last measurement on the screen from
memory.
Leakage on the pair effects the accuracy of the length
reading. For pairs under 1km (3000') in length, the
945DSP will tolerate 20K ohm of leakage resistance and
will measure to a ‘dirty open’ with as much as 20K of
series resistance. For longer pairs, leakage should not
exceed 200K. Do not measure distance through a load coil.
When the unit displays ---- in the result box, there is a fault
on the pair that prevents the 945DSP from making a
measurement.
Ring Length
Tip Length
Mutual
