8
9
Ground System Configurations
A ground resistance of less than 10
Ω
is required for proper operation of the
TerraStreamer
®
ESE Terminal. If, due to space constraints or high soil resistivity,
it is not possible to readily install a grounding system as recommended,
alternate grounding methods and designs shall be considered.
In order to meet safety and grounding system resistance requirements, Alltec
recommends the installation of a purpose designed and installed grounding
system such as the radial (crow’s foot) design or Delta design. Other
configurations and materials are allowed, and may be required due to local
conditions.
NOTE: Alternate grounding methods and designs are allowed by NF C
17-102, and Alltec is capable of designing a grounding system to meet
specific resistance goal in any type of soil.
D
D
P
P
B
B
D: Down-conductor
B: Building foundation loop ground
P: Grounding system
Radial
Delta
Fig. B
- Recommended Grounding Configurations
1. Installation of the Grounding System
Each radial should consist of a trench (approx. 50cm deep x 20cm wide x
10m length).
A ground rod should be driven at the end of each radial.
The use of copper conductor is recommended, with a cross sectional area
of not less than 50mm². Tin-plated copper is recommended for its corrosion
resistance.
All rods should be interconnected through the use of 1/0-19 strand bare
conductor and ground rod clamps or TerraWeld® exothermic welding. The
use of the TerraWeld® exothermic welding process is a safe and efficient
way of providing a permanent connection between conductors. TerraWeld®
connections will not rust or corrode over time.
ESE Grounding Systems should utilize TerraDyne® Electrolytic Ground
Electrodes and TerraFill® ground enhancement backfill to provide the
desired low resistance ground system and stabilize low contact resistance
at locations where the native soil has relatively high resistivity, low ground
