RS Pro ET-5300 Manuel D'instructions page 4

Earth Resistance Tester/English
Button Function Operation
Hold Function
The hold function freezes the reading in the display. Press the HOLD key momentarily to
activate or to exit the hold function
Backlight
Press the key to turn on the display backlight function. The backlight will automatically
turn off after 15 seconds.
Measurement of effective resistance of earth electrodes
BEFORE PROCEEDING MEASUREMENT, READ SAFETY NOTES ON PAGE 1.
1.In proceeding with measurement, if symbol
new batteries.
2.Short the tips of the leads and press the "TEST" button. Adjust the 0
control to set the reading of zero.
3.Rotate function switch to "EARTH VOLTAGE" position and press to test. Earth voltage
will be displayed on the LCD. When the earth voltage is more than 10V, it may result in
errors in earth resistance measurement. Accurate earth resistance measurement may not
be made.
4.Precision earth resistance measurement method :
(1)Connect green, yellow and red test leads to instrument terminals E, P and C with
auxiliary earth spikes P1, C1 stuck into earth "IN A STRAIGHT LINE ".(Fig.1)
(2)Rotate the function switch to suitable range then press the pushbutton to test and take
the reading.
Auxiliary
Earth
Spikes
4
appears on the display, replace with
"ADJ" turncap
Green
Yellow
Red
Earth
5-10m 5-10m
Electrode
under test
Fig.1
13/08/2017 Version No. 001
5.Simplified earth resistance measurement method :
(1)This method is recommended where an earth resistance higher than 10
or where it is not possible to drive auxiliary earth spikes. An approximate value of earth
resistance can be obtained by the two wire system (shown in Fig. 2).
(2)Rotate function switch to "EARTH VOLTAGE" position and press to test. Make certain
that earth voltage is less than 10V.
(3)First rotate function switch to "200 " position and press to test, read earth resistance.
If the display shows "1"(MSD), switch to "2000 " position and read earth resistance.
The reading obtained (Rx) is an approximate earth resistance value. There is no need for
external shorting as P and C terminals are shorted by using the test leads specified for the
Simplified measurement.
Green
Red
Fig.2
(5)Rx = Re – re
Rx = True Earth Resistance
Re = Indicated Value
re = Earth Resistance of Earth Electrode
(6)Since measuring current is as low as 2 mA, the earth leakage breaker (ELCB) does not
trip even if the earth side of the commercial power supply with an ELCB is used.
* Follow the proper connection such as Fig 2.
13/08/2017 Version No. 001
Earth Resistance Tester/English
is measured
Earth
Electrode
under test
5