AEMC 4500 - Ground Resistance Measurement Procedures

Digital Ground Resistance Tester Model 4500 29
4.5 Ground Resistance Measurement Procedures
(3-Point)
Y
X
X
v
TEST RANGETEST CURRENT
2
10
50
2
20
200
2
20
Alligator Clips
YZX
52% 62%
72%
0%
100% of distance
between X and Z
Ground RodY Electrode Z Electrode
Ground Rod
Y Electrode
Z Electrode
Ground
Strip
-10% 3rd
Measurement
+10% 2nd
Measurement
Figure 15
Warning: Do not disconnect the ground of a live circuit.
• XandXv(C1,P1)areshorted.
• ConnectXtothegroundrodtobetested.
• ConnectY(P2)tothecentralelectrode.
• ConnectZ(C2)tothefartherelectrode.
• Usetherangeselectorswitch,andselectarangewithameasurement
capability between 2 and 2000Ω.
• Using the test current selector switch, select the highest current for
which you observe a stable reading, and for which the display is not
blinking, or use the following guidelines:
2Ω
1mΩ
10mA or
50mA
20Ω
10mΩ
200Ω
0.1mΩ
2000Ω
1Ω
2mA or
10mA
20kΩ
10Ω
2mA or
10mA
Ranges
Resolution
Recommended
Current Ranges
2mA, 10mA,
or 50mA