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STANDARDS AND GUIDELINES FOR COMMUNICATION SITES CLAMP-ON OHMMETER TESTING PROCEDURE
DISPATCH CENTER
Clamp-on Ohmmeter
FIGURE D-8 CLAMP-ON OHMMETER PLACEMENT FOR PARALLEL GROUNDING ELECTRODE SYSTEM
D.4.3.4 MULTI-BONDED/MULTI-GROUNDING (EARTHING) ELECTRODE SYSTEM TESTING
For a site using a multi-bonded/multi-grounding electrode system, perform the test as follows:
NOTE: This test requires the site grounding electrode system to be bonded to the power company neutral wire,
but may require all non-balanced (phase-to-neutral) loads within the site to be switched off.
1. Coordinate the test with the customer and/or site owner and all other affected parties. Have all nonbalanced
(phase-to-neutral) loads switched off from the system under test.
NOTE: Unbalanced current flow (current on the neutral wire) within the site may affect the ability of the meter
to achieve an accurate reading. As such, arrange for any non-balanced (phase-to-neutral) loads within
the site to be electrically de-energized, yielding a neutral connection with no current flow on it. The
easiest way to accomplish this is to completely de-energize the AC power to the site. Any current on the
neutral wire (even if less than 5 amps) can result in a false reading.
2. Disconnect any other utility connections to the grounding electrode system, such as the telephone
company ground connection or paths through metallic pipes.
3. Have the Power Company neutral wire exposed by a qualified electrician at the point of entry into
the site, ensuring that it has no secondary path to the site via a conduit or other connection.
68P81089E50-B 9/1/05 D-17