ANSI A300 (Part 4)-2014 Lightning Protection Systems
This part of the A300 standards applies to installation and maintenance of Lightning Protection Systems in Trees.
Part 4 Lightning Protection Systems addresses:
- Tools and equipment
- Connectors and Fasteners
- Ground terminals
- Installation practices
A300 Part 4 Lightning Protection Systems standards recognize three basic ground systems:
- Single ground rod: A ground terminal composed of one ground rod.
- Multiple ground system: A ground terminal composed of two or more ground rods or copper ground plates.
- Horizontal ground system: A ground terminal composed of
ground rod(s) or copper ground plate(s) that are not fully driven or
installed in the ground due to site conditions.
The objective of a tree lightning protection system is to provide a
preferred path to ground for the electrical charge; protected trees
shall not be considered a safe haven from lightning strikes.
When considering tree lightning protection systems, the user has to
keep in mind that the purpose of the ANSI A300 (Part 4)-2008 standard is
to provide standards for developing specifications for tree lightning
protection system installation (43.1). The only reason for installing a
tree lightning protection system is to reduce the risk of damage to
trees from lightning strikes (43.2). Tree lightning protection systems
do not protect buildings or property from damage or provide safe havens
from lightning. The user needs to understand that the only objective for
a tree lightning protection system is to provide a preferred path to
ground for the electrical charge (46.1).
If there is danger from side flash or other lightning-induced damage
to non-tree components, property, buildings, etc., or, the trees owner
or owners agent have a different objective than outlined in this
standard (46.1), then the appropriate standard practices must be
followed as detailed by this standards normative references (44).
Which trees should be protected from lightning strikes?
- Trees with trunks within 10 feet (3 m) of a structure, or with
branches that extend to a height above the structure, should be equipped
with a lightning protection system because of the danger of side flash,
fire, or superheating of the moisture in the tree, which could result
in the splintering of the tree. (NFPA – 780 F-1)
- Trees of historical interest; trees of unusual value; shade trees
within 10 feet (3 m) of a building; trees with branches overhanging
buildings; tall trees in recreational or park areas; trees that are more
likely to be struck by lightning due to their location, such as
isolated trees on a hill, in a golf course, or in a pasture, etc.; and
similar trees; should be equipped with lightning protection systems.
- Lightning protection for trees is intended to safeguard trees
against damage caused by lightning; protected trees should not be
considered a safe haven from lightning strikes.
Part 4 Lightning Protection Systems Resources:
Download "Providing Lightning Protection
" a TCI Magazine article written by Guy Meilleur.
Learn about lightning protection systems
In this video, Steve Nagy of Davey Tree advises why lightning protection systems are necessary to safeguard against damage, and
recommends materials needed to create an effective system.