New Specialty Services —Testwell now provides GROUNDING & LIGHTNING SYSTEM INSPECTIONS Installation Verification & Mapping of Grounding
Systems
Soil resistivity consists of soil composition, moisture and temperature.
It stands to reason that soil resistivity will vary through out
the year in those areas of the country where seasonal changes bring
about a change in the moisture and temperature content of the soil.
Soil that is low in resistivity is often highly corrosive because
of the presence of water and salts, and this soil can eat away at
ground rods and their connections. That is why it is highly recommended
that grounds and ground fields be checked at least annually. Although
resistance to ground will change seasonally and over time any increase
to resistance >20% or more should be investigated and corrective
action taken to lower the resistance.
The measuring procedure for Soil Resistivity and Ground Resistance
uses the universally accepted Wenner method developed by Dr. Frank
Wenner of the US Bureau of Standards in 1915. (F. Wenner, A Method
of Measuring Earth Resistivity; Bull, National Bureau of Standards,
Bull 12(4) 258, s 478-496; 1915/16.) . Note that NEC 70(2002) calls
for grounding system compliance, as does the New York City Electrical
Code.
Contact us for
Soil Resistivity measurement
Grounding Rod installation verification
Measurement of grounding system resistance
by spike less method
Verification of system grounding after
modification/cable splicing/construction alterations
To learn more, call
Paul Moretti at 914.944.2529 or AK Mishra at 914.944.2593
