− 8 −
5-5 Earth resistance measurement: 3-pole method
5-5-1 Preparation
①
Connect the black test lead plug into E terminal, blue test lead
plug into S(P) terminal and red plug into H(C).
②
As illustrated below, place S(P) and H(C) auxiliary earth
electrode into the ground and clip the Earth by E in one line at 5
to 10 m interval. It is better to put each test leads a little away.
EARTH TESTER
PDR4000
POWER
REL
HOLD
TEST
ACV
40Ω
400Ω
4000Ω
>
2s
AUTO POWER OFF
TEST OUT PUT
CAT.III 300V
CAT.II 400V
ACV 400V
MAX
E
S
(
P)
H
(
C)
5~10m 5~10m
Earth
Earth
Black
Black
Blue
Blue
Red
Red
E
E
S
(
P
)
S
(
P
)
H
(
C
)
H
(
C
)
Note:
Please place the auxiliary earth electrode as much as possible
into the moist area. If you place it into a place where there are
many pebbles, sandy lands, dry place, please add water and
damp it.
On the concrete, lay the auxiliary earth electrode and measure it
with water and a damp cloth. But asphalt can not be measured
because water does not penetrate.
If the auxiliary earth electrode resistance is too high to measure,
add water to it, insert deeper, clean it. If it does not decrease due
to the characteristics of the soil, please rework to another place.
5-5-2 Interference voltage check ACV
After preparation, check interference voltage at ACV function
first. The voltage is between E and S(P). If reading is 10 V or more,
earth resistance measurement can not be performed.
In this case power off equipment in the earth system, which may
be connected to ground to avoid leakage current flow.
5-5-3 Measurement
①
Set the function to 40 Ω/400 Ω/4000 Ω
②
Press the TEST button to make earth resistance measurement.