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Field applications – ERICO EST401 ERITECH Clamp-on Ground Resistance Tester User Manual

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Field Applications

Service Panel

If we clamp-on the grounding electrode conductor in Fig. 20, the multi-grounded system
required to complete the circuit may be from different sources. These sources may include
the following: Electric Neutral, Phone, CATV, and Water.

The Electric Utility Neutral should be the principle conductor of the low-impedance signal
return path required to test the resistance of this ground electrode with the EST401. This
can be verified by removing other ground connections, noting if any changes appear in the
readings. If by removing one of these signal return paths a much higher reading is noted,
it could mean that the primary signal return path (the Electric Neutral) is defective or open.

Warning: For safety reasons do not remove any ground source without first
de-energizing the service panel.

!

Figure 20

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