Earth Resistance Measurement With 4-Wire Method (R 4P) - Sonel MRU-200 User Manual

3.4 Earth resistance measurement with 4-wire method (R
The 4-wire method is recommended in the case of measurements of earth resistance of very low
values. It permits to eliminate the influence of the test leads resistance over the result of the meas-
urement. In order to evaluate the resistance of the ground it is recommended to use the dedicated
measurement function (point 3.9).
Disconnect the tested earth electrode for the object installation.
Connect the current electrode driver into ground to the H socket of the meter.
Connect the voltage electrode driver into ground to the S socket of the meter.
Connect the tested earth electrode to the E socket of the meter.
Connect the ES socket to the earth electrode In question below the E cable.
The tested earth electrode as well as the current electrode and voltage electrode
should be aligned.
MRU-200 ● MRU-200-GPS – USER MANUAL
Turn the meter on.
Set the rotational
function selector at 4P.
E ES S H
E ES S H
The meter is ready for measurement.
The auxiliary display shows the value
of the interference voltage and its fre-
quency. The setting bar shows the
mains frequency set in the MENU.
4P)
E
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