GroundFlex™ Adapter Model 6474
13
To display the measurement parameters, press
DISPLAY
several times.
The device displays the following parameters:
R
SEL
, U
S-ES
and its frequency, I
SEL
, R-Act (R
PASS
), U-Act (U
S-ES
and its frequency,
U
H-E
and its frequency), I-Act (I
SEL
and its frequency).
To measure the resistances of electrodes
H (Z)
and
S (Y)
, or if the resistance of
the electrodes is too high, start the measurement by a long press of the
START/
STOP
button.
R
H
, R
S
, U
H-E
, I
H-E
will be displayed.
2.3.3 Other Measurements
As explained above, terminals
ES (Xv)
and
E (X)
must be connected to a metallic
part of the pylon above the GroundFlex
™
sensor in order to measure the current
flowing ISEL
downward
through the sensor, therefore to the earth to measure
ground resistance of the leg. If connections
ES (Xv)
and
E (X)
are placed below
the GroundFlex
™
sensor, the latter measures the current flowing towards the top
of the pylon via the overhead earth wire at its tip, and you can in this way evaluate
the
quality of this counter poise
. You can even make this measurement without
moving the contacts of
ES (Xv)
and
E (X)
on the pylon by simply passing the 2 con
-
necting cables through the GroundFlex
™
sensor. The current in connecting cable
E
(X)
and the current through the leg of the pylon then cancel each other out.
You can also measure
any leakage currents
(I-Act) flowing through each leg of
the pylon in normal operation of the high-voltage line. If you find different leakage
currents in each leg, but they cancel out when added together, you can conclude
that these currents, induced by the rotating field of the high-voltage lines,
indicate
an earthing fault
of the pylon
via the overhead earth wire at the tip of the
mast
.
2.3.4 MANUAL Mode and SWEEP Mode
Use the
Hz/OPTIONS
button and ► button to change to
MANUAL
mode. The
following parameters can be modified:
128Hz blinks
•
Change the test frequency
Test voltage blinks
•
Switch between 16 and 32V
You can also perform a frequency sweep and a smoothing.
In the sweep mode, the measurements can be made at frequencies up to 5kHz.
On a single pylon, frequencies of the order of 5kHz do not always entail inductive
effects, but the "current loops" formed by the adjacent pylons and the return chan
-
nel through the ground may result in inductances that can be detected only at high
frequencies.
