Installation Guide

use any clips or other devices that are conductive and form a closed loop. Closed conductive
loops form a grounding choke point during high voltage spikes that have an adverse impact
on grounding performance. Metallic clips are acceptable if they do not form a closed loop. A
metal clip that is "U" shaped but is mounted on a conductive metal surface is considered a
closed loop.
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Ground Rod. 5/8-inch x 8-feet (minimum length) steel with pure copper jacket not less than
0.0012 inches thick.
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Ground Rod Coupling. 5/8-inch ground rod coupling made of the same material as the
ground rod to prevent dissimilar metal high oxidation points.
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Chemical Ground Rod. Comprised of a hollow copper ground rod, a ground test well, a 4’-
0" exothermically welded pigtail, and conductive backfill material. The chemical ground
electrode must be made of a minimum two inch I.D. Type K copper tube with a minimum wall
thickness of 0.083 inch and must be a minimum of 10 feet in length. Fill the chemical ground
rod copper tube with non-hazardous metallic salts. The chemical ground rod must be UL
listed. In situations where drilling vertically is too difficult or costly, horizontal L-shape
chemical ground rods are acceptable.
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Ground bars. Bars must be 1/4 inch thick solid electrical grade copper and must be
electroplated with tin 0.0003 inches thick typical, 0.0002 inches thick minimum. Hole spacing
between top row and center row holes must be ¾ inch, between center row and bottom row
holes must be 1 inch (Telco), and between top row and bottom row must be 1 ¾ inch
(NEMA). Connect ground lugs as shown in Figure 2-1. Ground lugs on opposite sides of the
ground bar may share holes in the ground bar if connected properly.
Warning! Never mount lugs on top of each other on a ground bar.
The following illustration shows the installation of ground wire to ground bar.
23 June 2020 TDC-0971-012 Itron, Inc. Page 109 of 134
CCU 100 and Repeater 100 Installation Guide F Grounding Specifications