16
3.1 Normal Grounding Resistance Test
a.
Setting up the connection
Refer to the Figure, align the auxiliary earth bar P1, the auxiliary earth bar C1
and the earth electrode E in a line. C1 and P1 must be 5 to 10 meters apart, P1
and E must be 5 to 10 meters apart.
Drive the auxiliary earth bare C1 and P1 into the ground. Connect C1 to "C"
terminal using the red normal-test lead, connect P1 to "P" terminal using the
yellow normal-test Iead, connect the earth electrode E to be measured to "E"
terminal using the gram normal-test lead.
The grounds where P1 and C1 are driven must have high water content. For the dry
ground, send ground and gravel ground, you must add water to the auxiliary earth
bare' positions. For cement ground, place the auxiliary earth bars an the ground, add
water to the bars' positions, then respectively cover the bare with damp towels, then
do
the
measurement.
b. Checking the connections
b1.
Checking the connection between "C" and "E" terminals: Set the
function/range switch to a resistance range, then press "TEST" button. lf the
LED gives green light, the connection between "C" and "E" terminals is good
and the grounding resistance of the bar C1 is in permitted range.
lf the LED gives red light, do the following steps until the LED doesn't give red
light when you measure grounding resistance:
Check the connection of the red normal-fest lead. Check the connection of the
green normal-fest lead. Change the bar C1 to another permitted position.
Add water to the bar C! position to reduce the bar's grounding resistance to a
appropriate
value.
b2.
Checking the connection of the yellow normal-test lead: Remove the red
normal-fest lead from "C" terminal, move the plug of the yellow normal-test
lead to "C" terminal ( the yellow clip is still connected to bar P1). Set the
function/range switch to a resistance range, then press 'TEST" button. If the
LED gives green light, the connections are good, and the grounding resistance
of the bar P1 is in permitted range.
If the LED gives red Iight, check the connections or change the bar P1 to
another permitted position or add water in the position of bar P7 to reduce its
grounding
resistance.
b3.
Checking with a known resistor
Use a resistor of 1000 to check. Connect the red clip and the yellow clip to one
terminal of the resistor, connect the green clip to the resistor's another
terminal. Set the Function/Range switch to "200 Ohm" Position, press "TEST"
button. If the reading on the display is about "100.0 Ohm", the three normal-
fest Ieads are good, otherwise the fester or at least one normal-test lead
connection is bad. Note: The red normal-fest lead is connected to "C"
terminal, the yellow normal-test Iead is connected to "P" terminal, the green
normal-fest Iead is connected to "E" terminal.
