13
®
®
14
H.i55
I i0
EARTH-
TESTER
0
10
20
30
40
C
MEM
AL
CLR
SET
START
FUNCTION
OFF
EARTH
R
EARTH
EARTH
VOLTAGE
OFF
C
(H)
E
P
ES
(S)
AC 600V Max
Rs232
V
P
(S)
ES
ES
P
(S)
Green
Yellow
N
L
4. Earth Voltage Measurement :
Earth voltage measurement need to use one auxiliary
earthing rod.
The meter connect with the earth only by testing wires
and auxiliary earthing rods. Other tester wires of
meter’s interface can’t connect with commercial
power line L, N, otherwise may cause leakage, the
breaker may start, it is dangerous.
Earth voltage measurement can’t exceed 600V.
Earth voltage :
That is a potential differences between zero
potential differences and earthing equipment shell, earthing wires,
earthing body when electrical equipment has a earthing fault.
Earth voltage is the potential differences between the earth. As a
reference point, the earth is zero potential.
Earth voltage measurement need to use one auxiliary earthing
rod. Please pay attention to the difference from commercial AC
voltage measurement. As shown below : meter, auxiliary earthing
rods, testing wires are all connected, rotate rotary
switch to “
EARTH VOLTAGE
” and start testing, LCD will display
the test results.
FUNCTION
H.i65
07 i
EARTH-
TESTER
0
10
20
30
40
C
MEM
AL
CLR
SET
START
FUNCTION
OFF
EARTH
R
EARTH
EARTH
VOLTAGE
OFF
C
(H)
E
P
ES
(S)
AC 600V Max
Rs232
V
P
(S)
ES
ES
P
(S)
Green
Yellow
.
Secondary
circuit
Transformer
First
circuit
Measured earthing body
Measuring earth voltage of commercial earthing body
5. 4-wires Precise Earth Resistance Measurement :
In the testing of earth resistance, should firstly confirm
the earth voltage of earthing wire, the voltage between
C
(H)
and E or P
(S)
and ES must under 20V, the meter
showing symbols when the earth voltage exceed
5V, and the measured value of earth resistance may
produce error. At this time, firstly interrupt power
supply to earthing equipment, make sure the earth
voltage decrease, and then test earth resistance again.
NOISE
4-wires Measurement :
The 4-wires method can eliminate
influence of contact resistance (usually result from dirty or rusty)
between measured earthing body, auxiliary earthing rods, test
clips, meter’s input interface. The 4-wires method can also
eliminate influence of line resistance. So it is better than 3-wires
measurement.
As shown below :
Start from the measured body, interval 5m-
20m, respectively insert
P
(S)
,
C
(H)
auxiliary earthing rods deep into
the earth in a straight line, and then connect testing wires (black,
green, yellow, red) from
E
,
ES
,
P
(S)
,
C
(H)
interfaces corresponding
to measured earth electrode
E
, auxiliary voltage electrode
P
(S)
,
auxiliary current electrode
C
(H)
.
