Supplier General Requirements and Equipment Competencies
Itron requires that all suppliers have previous telecom experience and have the following
equipment and resources:
• Certified, Clamp-On Ground Resistance testing devices (or equivalent)
• Competent trained operators readily available
• Megger DET14C/24C Clamp-on Ground Resistance Tester, or equivalent
• Maintain the capability to document ground resistance testing data by digital
photograph and be able to convert the photos to Adobe Acrobat files, to be
transmitted within 24 hours of completing testing.
Exterior Grounding System Design for Concentrators
Materials making up the grounding and bonding system must meet the following
minimum standards:
• Wire underground. Minimum No. 2 American Wire Gauge (AWG) bare, solid,
annealed, tinned copper wire (BTCW) but sized in accordance with NEC Table
250.66. Under no circumstances is stranded wire acceptable. Install all buried wire to
meet minimum bend radius. Sharp bends and kinks are never acceptable.
Note When any grounding or bonding wire runs through concrete, sleeve it in PVC.
• Wire inside. Any low halogen cable meeting the ratings of Telcordia GR-347 is
acceptable.
• Clips. When securing any ground wires, solid or stranded, insulated or un-insulated,
never 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.
• Ground Rod. 5/8-inch x 8-feet (minimum length) steel with pure copper jacket not
less than 0.0012 inches thick.
• 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.
• 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.
TDC-0971-011 CCU 100 and Repeater 100 Installation Guide 97
Proprietary and Confidential
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