Making A Measurement (Resistance Of Legs) - AEMC GROUNDFLEX 6474 User Manual

NOTE: To increase measurement sensitivity, we recommend when possible,
wrapping a maximum number of turns (up to 4) around the structure.
3. Set the INPUT SELECTION switch accordingly. You can measure the current
flowing through one GroundFlex
sensors (1, 2 or 1, 2, 3), or through all of the sensors (1, 2, 3, 4).
4. Select how many times the sensor is wrapped around the conductor to be
measured (from 1 to 4 turns) using the SENSOR TURNS switch.
5. Set the SENSITIVITY switch to the desired sensitivity: x1/10, x1, or x10. The
choice of sensitivity depends on the expected current value. As a precaution,
always start with the lowest sensitivity, x1/10, and increase it as needed.
2.3.2

Making a Measurement (Resistance of Legs)

1. Place auxiliary electrodes H (Z) and S (Y) on opposite sides of the pylon, as
far away as possible (100 - 150 ft) and, if possible, perpendicular to the high-
voltage line (depth is not important). This will eliminate interference with the
measurement by stray voltages or currents induced under the high-voltage
line.
2. In order to avoid electromagnetic interference, it is best to unwind the full
length of each cable from the reel, to keep the cables as far apart as possible
on the ground, taking care not to form loops, and to avoid placing the cables
near or parallel to metallic conductors (cables, rails, fences, etc.). Effects of
interference are measured in milli-ohms.
3. Connect these auxiliary electrodes to terminals H (Z) and S (Y).
4. The terminals ES (Xv) and E (X) must be connected to a conducting metallic
part of the pylon located above the GroundFlex
surement of the current flowing downward and towards the earth (otherwise,
you would measure the current flowing upward, from the earth to the tip of the
pylon).
GroundFlex™ Adapter Model 6474
To the Model 6472
sensor (1, 2, 3, or 4), or through several
™
6474
sensors. This ensures mea-
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