10/5/15
Lightning Protection System—Quality
Installation and Maintenance
Lightning Protection System—Quality
Installation and Maintenance
Michael J. Johnston
NECA Executive Director Standards & Safety
Mark S. Harger
President/CEO Harger Lightning & Grounding
This session is eligible for
1 Continuing Education Hour
and 1 Contact Hour.
To earn these hours you must:
– Have your badge scanned at the door
– Attend 90% of this presentation
– Fill out the online evaluation for this session
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10/5/15
Why
• There is no ANSI accredited lightning
protection standard that addresses best
practices
• Less than 2% of all UL Master Label
installations get re-inspected after the 5
year date
• Most lightning protection systems on
structures are not being maintained
Outline
1.0
2.0
3.0
4.0
5.0
6.0
7.0
Scope
Definitions
Design Procedures
Installation
Acquisition of Master Label® Certificate
Inspection, Maintenance and Ground Testing Procedures
Project Management Procedures
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1.0 - Scope
• To provide a “Best Practices” Lightning
Protection System Installation Standard
that ensures the completed installation
complies with the requirements of NFPA®
780, Standard for the Installation of
Lightning Protection Systems.
• This standard will cover both new and
existing structures.
2.0 - Definitions
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Definitions
ANSIA United States standards organization
responsible for promoting and facilitating
voluntary consensus standards and
safeguarding their integrity.
Definitions
Down ConductorA main conductor that carries
lightning currents from the top
of the structure to the
grounding electrodes.
Down Conductor
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Definitions
ExothermicA process that produces a welded
connection between a conductor and
other objects.
Definitions
Ground Access WellA protective enclosure which allows the
ability to inspect and test individual
grounding electrodes or the grounding
electrode system.
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Definitions
NFPA 780An ANSI recognized installation standard
for lightning protection systems.
Definitions
Roof ConductorA main conductor located at the roof level
that interconnects strike termination
devices to down conductors.
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Definitions
Thru-RoofA connection device that assists in creating
a water tight seal when penetrating a roof.
Definitions
Thru-WallA connection device that assists in creating
a water tight seal when penetrating a wall.
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3.0 - Design Procedures
• The lightning protection design shall be in
accordance with the requirements of NFPA
780, standard for the insulation of lightning
protection systems.
Design Procedures
The company providing the design should
have a minimum of 5 years experience and
be well versed with NFPA 780.
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Design Procedures
Example of a proper lightning protection shop
drawing.
Design Procedures
Example of a proper lightning protection shop
drawing details.
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Design Procedures
Generally, it is not advisable to rely on the
lightning protection design information provided
with the original plans as shown by this
example.
Design Procedures
This is an example of a lightning protection
drawing designed to meet the requirements
of NFPA 780.
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Design Procedures
• Lightning protection systems are designed
specifically for the building or structures
they are intended to protect.
Design Procedures
The design is not only impacted by the shape
and size, but also by building systems and
structural components.
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4.0 - Installation
• The installation shall be in accordance
with the requirements set forth in NFPA
780 and installed in a neat and
workmanlike manner
4.1 Pre-Construction Site
Assessment
• When: Once the submittal drawings have
been approved and before construction
begins
• Why: To review important aspects of the
installation
• Who: Owner representative
Supervisor
Roofing contractor
Electrical contractor
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Pre-Construction Site Assessment
• Items to be discussed
• Location and placement of ground
electrodes and down conductors
• Responsibility for sealing thru-roof
penetrations
• Installation of adhesive mounting pads (if
required)
4.2 Ground Electrode Installation
and Common Bonding
• Ground electrodes shall be installed in
accordance with NFPA 780.
• Common bonding between all building
electrode systems shall be installed in
accordance with NFPA 780 and NEC 70.
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Ground Electrode Installation
• For testing and maintenance, access of
each ground electrode should be
available.
Ground Electrode Installation
• Ground rods should be
driven far enough away
from the footing and drain
tile and also past the
roof’s drip edge.
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Ground Electrode Installation
• Ground rods shall be installed into
undisturbed soil.
• If it is not practical to install ground rods
outside of the building, the ground rods
should be installed as close to the
building’s walls as practical without
damaging the footing.
Ground Electrode Installation
The correct ground rod driver adapter
should be used to avoid mushrooming or
damaging the end of the ground rod.
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Ground Electrode Installation
If the damage to the ground rod is to severe,
the top of the rod may need to be cut off so
that the ground rod clamp or exothermic
connection can be properly made.
Ground Ring Electrode Installation
If required, a ground ring electrode for the
lightning protection system shall be installed
at least 18 inches below earth unless
prohibited by ground conditions.
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Ground Ring Electrode Installation
A ground ring electrode
installed for the purposes
of electrical grounding shall
be installed to a depth of at
least 30 inches.
Ground Ring Electrode Installation
• Ground ring electrodes shall be
continuous around the structure and
connected to all down conductors.
• The ground ring electrode shall be
installed below the frost line (if present)
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Common Bonding
• Per NFPA 780, all grounding
systems and underground
metal piping that enters a
building shall be bonded to
the lightning protection
system within 12 feet of
grade level.
Common Bonding
• Other grounding systems to be bonded
include but are not limited to;
– Electrical service
– Communications
– Cable television
– Antenna systems
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Common Bonding
• The use of an intersystem bonding
termination device may help facilitate
these connections.
Common Bonding
• A master ground bar is another choice to
help facilitate these connections.
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Common Bonding
• Buildings exceeding 60 ft. in height, the bonding
connections shall be made to a ground loop
conductor.
• A ground ring conductor can serve as a ground
loop conductor.
4.3 Down Conductors & Bonding
• When installing, ensure paths for down
conductors are clear of obstructions, such
as HVAC ducts, large pipes or structural
columns or beams.
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Down Conductors
• Lightning conductors must
maintain a horizontal or
downward path from air
terminals to the grounding
electrode.
Down Conductors
• Down conductors shall be placed as
widely as practicable around the perimeter
of the building.
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Down Conductors
• Sharp bends and splices in down
conductors should be avoided.
• Bends and splices increase the
impedance of the conductor.
Down Conductors
• Down conductors shall
be securely fastened to
the structure at
maximum 3 feet
intervals.
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Down Conductors
• The conductor clips and hardware must be
the same material as the conductor or a
material equally resistant to corrosion.
Down Conductors
• When routing down
conductors through
exterior walls, a thru-wall
device should be used to
prevent moisture from
entering the structure.
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Down Conductors
• Exposed down conductors
in areas subject to
physical damage of theft
shall be protected with
guards or conduits at least
6 feet above grade.
Down Conductors
• Down conductors that are installed in long
vertical conduits or raceways should be
supported to reduce the strain on the
conductor.
– Class I conductors should be supported every
100 ft.
– Class II conductors should be supported
every 80 ft.
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Down Conductors
• Buildings with
electrically continuous
structural metal
framework, the metal
should be used as
down conductors.
Down Conductors
• When using the structural
metal as a down
conductor, the metal shall
be cleaned down to base
metal, removing all paint,
rust, and mill scale to
avoid high resistance
connections.
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Down Conductors
• When utilizing mechanical
connections, antioxidant
joint compound should be
used to prevent corrosion.
Down Conductors
• Routing down conductors in both new and
existing construction may require
reestablishing the integrity of fire-rated
walls, floors, and ceilings.
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Bonding
• Where down conductors
are run on buildings with
structural metal
framework, each down
conductor shall be
bonded near the top and
bottom.
Bonding
• Steel reinforced concrete
columns or CMU walls with
reinforcing steel. The rebar
shall be bonded at the top
and bottom of the down
conductors.
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Bonding
• Grounded metal objects
near down conductors
may require bonding if
located within the
calculated “side-flash” or
bonding distance.
4.4 Thru-Roof Installation
• Installation of thru-roof’s should be
reviewed with the roofing contractor,
roofing manufacturer, architect and
engineer prior to installation.
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Thru-Roof Installation
• Thru-roof’s are designed
to accommodate various
ranges of roof thickness.
• The thru-roof’s
assemblies should be
modified at the site so
they extend not more
than 9 inches above the
completed roof.
Thru-Roof Installation
• Thru-roofs should not be installed in low
areas of flat or gently sloping roofs.
• On pitched roofs, thru-roofs should not be
located in valleys or near gutters.
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4.5 Roof Top Installation
Location & Mounting of Air Terminal Bases
• Generally air terminal bases are first to be
mounted to the roof.
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Location & Mounting of Air Terminal Bases
• The layout of air
terminal bases
typically start in
the corner.
• The length of
the roof edge or
ridge is divided
into equal
spaces.
Location & Mounting of Air Terminal Bases
• When mounting air
terminals near
corners and edges,
the conductor must
maintain at least a
minimum 8 inch
radius bend.
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Location & Mounting of
Air Terminal Bases
• When mounting air terminals on roof-top
equipment, make sure that access panels
are not obstructed.
Location & Mounting of
Air Terminal Bases
• Air terminal bases must be securely
attached to the structure with corrosion
resistant hardware.
• If adhesive is used, the roofing contractor
and manufacturer must be consulted and
they must make sure the adhesive is
compatible with surface it is to be mounted
to.
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Routing of Roof Conductors
• Shop drawings will give the general
routing of conductors on the roof.
• The number of splices and connectors
may be minimized with some forethought.
• Conductors must be routed to avoid sharp
bends of less than 90 degrees or radius
bend less than 8 inches.
Routing of Roof Conductors
• As with air terminal bases, conductors
should be securely attached to the
structure at maximum 3 feet intervals or
less in areas where movement of the
conductor is of a concern.
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Routing of Roof Conductors
• Conductor that must run through the air for
more than 3 feet must be supported.
• Avoid routing conductors perpendicular to
the slope of pitched roofs where ice, snow
or debris can collect.
Routing of Roof Conductors
• Care should be taken when routing conductors to
account for temperature change. Copper and
aluminum conductors expand and contract.
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Routing of Roof Conductors
• When routing roof conductors
through walls, a thru-wall device
should be used to prevent moisture
from entering the structure.
4.6 Performance and Quality
Control Issues
• Materials used in the installation of a
lightning protection system must be listed
or labeled by U.L. for use in lightning
protection systems.
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Materials
• Although a component may have the UL
mark and be listed for the purpose of
electrical work, it may not be listed to be
used in a lightning protection installation.
Materials
• Lightning protection materials must be
compatible with the surfaces to which they
are mounted.
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Materials
• Confirm the compatibility of materials
when making bonding connections to
metal objects.
• Bimetallic connectors may be required.
Materials
• Adhesives used must be compatible for
two important reasons.
– The adhesive must be compatible with the
surface it is being applied to ensure that it will
not destroy the roof membrane or other
surfaces.
– Compatibility is important to make sure that
the adhesive functions properly and the
components are held in place.
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Exothermic Connections
When making exothermic connections, all
parts of the connection must be clean and
free of moisture before making the
connection.
Conductor not properly cleaned
Mold and conductor not properly dried
5.0 Acquisition of Master Label®
Certificate
• A Master Label® Certificate indicates to
the building owner that the installed
lightning protection system meets the
requirements of an installation standard.
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Master Label® Certificate
• A Master Label® Certificate remains valid
from the time of inspection until the
expiration date unless modifications are
made to the structure.
• A Master Label® Certificate expires five
years after the inspection date.
Inspection Procedure
• The installer is responsible for coordinating
access to all portions of the structure
necessary to verify compliance with the
specified standard. Some of these areas are;
– Main electrical power/distribution room
– Main communications room
– Service utilities such as sewer, fire suppression,
etc.
– Rooftop
– Attics
– Basements
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Submitting an Application
• Request for inspections shall be done
through UL’s web page.
• Submitting on line is a declaration that the
installation complies with the applicable
requirements.
Post UL Inspection Documents
• Upon successful completion and
inspection of the lightning protection
system, the Master Label® Certificate will
be issued to the building owner and the
installation contractor.
• It is the installation contractor’s
responsibility to ensure the Master Label®
Certificate is published on UL’s public
directory.
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6.0 Inspection, Maintenance and
Ground Testing Procedures
Inspection and Maintenance
• Installations should be inspected upon
completion and shall be required if the
Master Label® Certificate is specified.
• A maintenance manual should be provided
to the building owner upon completion of
the installation.
6.1 Inspection and Maintenance
• Periodic annual inspections are
recommended, more frequent inspections
may be required based on the following.
– Environmental conditions
– Classifications of the structure or area
protected
– Mounting surface for lightning protection
components.
– Lightning protection materials used.
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Inspection and Maintenance
• The lightning protection system should
also be inspected whenever any
alterations or repairs have been made and
if any lightning strikes have known to
occur.
• In-depth inspections should be conducted
every three to five years.
6.2 Visual Inspections
• Visual inspections are used to determine:
– Systems in good operating condition
– No loose connections
– No components have been compromised
– No down conductors have been detached,
severed or stolen
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Visual Inspections
• Visual inspections are also used to
determine:
– Grounding electrodes are still attached
– All conductors, fasteners and other
components are securely attached
– No alterations or additions have been made to
the structure
– Surge protection devices are still operational.
– Lightning protection system is still in
compliance with NFPA 780
• Testing should be done to verify that
concealed parts of the system are still
electrically continuous as well as to
determine if any additional equipotential
bonding is needed.
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• Ground resistance testing of the individual
grounding electrodes should be conducted
to determine if there has been any
increase in resistance since the original
installation.
6.3 Inspection Guides
• An inspection guide should be prepared and made
accessible to the party responsible for the lightning
protection system. The following data should be
covered.
– Overall condition of all lightning protection system
components.
– Presence of any corrosion or material wear.
– Presence of any loose components.
– Resistance measurements of grounding electrodes.
– Presence of any new building components
– Changes made to the system or structure noted on
the as-built drawings.
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6.4 Maintenance Programs
• A maintenance program should contain a
checklist of all items needing inspection
including the following:
– Inspection of all conductors
– Reattach any loose conductors and replace if
needed
– Inspect all fittings for tightness and corrosion.
– Test and record ground resistance of all
grounding electrodes.
– Inspect all surge protection devices
– Record any new additions made to the structure
Maintenance Programs
• Complete records should be kept of all
maintenance procedures and inspections
as they will assist in setting a baseline
assessment of the lightning protection
system and aid in establishing a
preventive maintenance program.
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6.5 Ground Testing
There are two acceptable methods to test
the resistance of a grounding electrode.
Three point fall of potential
Clamp-on test
Ground Testing
• “Fall of Potential” Method
– The grounding electrode system (if multigrounded neutral system) and
telecommunications ground must be
disconnected.
– Individual grounding electrodes must be
disconnected from the grounding electrode
system and be tested individually to
determine the resistance value.
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Ground Testing
• “Clamp-On” Method
– The grounding electrode system must be
connected to the electrical power system or a
zero reference source.
– Proper placement of the unit is essential in
order to obtain a correct reading.
– Grounding electrodes shall be tested
individually to determine the resistance value.
7.0 Project Management Procedures
Good project management procedures are
essential to the successful design,
installation and certification of a lightning
protection system.
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Project Management
• Project management begins with proper
planning that includes:
– Defining the scope of the project
– Determining the best work flow
– Having procedures in place to deal with
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Communications
Scope changes
Quality issues
Documentation
Project Management
• Project design drawings need to be
formalized into complete shop drawings
that are coordinated and confirmed by all
trade contractors as well as the architect
and engineer.
• Approved shop drawings form the basis
for the project documentation.
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Project Management
• Determining the best work flow also
requires proactive planning.
• Lightning protection systems interact with
most other building systems.
• It is important to anticipate installation of
other systems so that required
connections can be made.
Project Management
• Accurate documentation of the system
installation is critically important to
certification.
• Procedures must be in place to make
certain all concealed portions are
accurately documented on as-built
drawings as well as with dated photos.
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Questions?
Don’t forget…
• 10:15 - 11:30 am Special Session: Life on the Rock
• 11:30 am - 4:00 pm NECA Show Hours
www.harger.com
www.necanet.org
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