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   © Dr. Ray Franco, PhD, PE  -  208 Fairways Dr., Vicksburg, MS 39183

Lightning Damage


Lightning

Lightning is the transfer of electrical charge from cloud-to-cloud or cloud-to-ground. When lightning strikes the earth, it heats and expands the air. The expanding air causes a shock and pressure wave.

As electrical charge from a cloud approaches the ground, streamers from objects on the ground rise to meet the charge from the cloud. When the charge and streamer meet, electrical charge is moved from the cloud to the earth. An object that is taller has a higher probability of producing a streamer that will combine with charge from the cloud. Hence, taller objects are more likely to be struck by lightning.

Lightning is the transfer of electrical charge from cloud-to-cloud or cloud-to-ground. When lightning strikes the earth, it heats and expands the air. The expanding air causes a shock and pressure wave.

As electrical charge from a cloud approaches the ground, streamers from objects on the ground rise to meet the charge from the cloud. When the charge and streamer meet, electrical charge is moved from the cloud to the earth. An object that is taller has a higher probability of producing a streamer that will combine with charge from the cloud. Hence, taller objects are more likely to be struck by lightning.

Lightning Statistical Data

According to the National Fire Protection Association (NFPA), from 2007 through 2011, there were an average of 4,300 home structural fires per year caused by lightning. The average per annual property damage was $305 million dollars, and there were 7 deaths per year.

NFPA's Lightning Fires and Lightning Strikes, Marty Ahrens, June 2013

National Weather Service - Lightning and Fires

National Weather Service - Lightning Deaths

Lightning TreeDamage

When lightning strikes a tree, most of the electrical current takes the path of least resistance. The area just under the tree bark contains moisture in the form of sap and water. This area is more conductive than the bark on the outside of the tree. The path that lightning current took will often be depicted by missing bark on the tree.

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Missing Tree Bark depicting the Path of Lightning Current
Lighting Damage runing down the Trunk of a Pine Tree (F16-047).
Lighting Damager Higher in the Pine Tree
Lighting Damage Higher Up in the Pine Tree (F16-047).

Lightning Damage at My Mother's House

On 2014-06-09">June 9, 2014 at approximately 3:00 AM, lighning struck a large oak tree at the side of my mother's home: 1437 Westeria Drive, Vicksburg, MS 39183. Athough I could not find any phyical damage in the top of the tree, at the tree trunk were burned bark and boiled tree sap. The only items damaged inside the home were AT&T Internet and televison boxes (U-Verse).

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Tree on the Side of my Mother's Home
Tree on the Side of my Mother's Home (F14-VioletFranco).
Lightning Damage to the Trunk of the Tree
Lightning Damage to the Trunk of Tree (F14-VioletFranco).
 
Boiled Tree Sap at the Trunk
Boiled Tree Sap at the Trunk (F14-VioletFranco).
 

Lightning Damage to the AC Condenser and Furnace

Lightning damaged the AC condenser, the furnace, a refrigerator, a TV and other appliances in this home. The only physical signs of lighting damage were to the AC condenser and the furnace.

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Lightning Flash Burn Marks on AC Condenser Frame
Lightning Flash Burn Marks on AC Condenser Frame (AC06-001).
Lightning Flash Burn Marks on Top of AC Compressor
Lightning Flash Burn Marks on Top of AC Compressor (AC06-001).
Flash Burn Marks on Electric Furnace Door
Lightning Flash Burn Marks on Electric Furnace Door (AC06-001).
Flash Burn Marks inside Electric Furnace
Lightning Flash Burn Marks inside Electric Furnace (AC06-001).

Lightning Damage to an Electric Kitchen Range

Lightning struck the ground and indirectly damaged the kitchen range, washing machine and television set. There were signs of lightning damage to the ground and the kitchen range.

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Where Lightning Stuck the  Ground
Where Lightning Struck the Ground (F14-047).
Burn Marks Where Lightning Struck the Ground
Burn Marks where Lightning Struck the Ground (F14-047).
Lightning Damaged Kenmore/Roper Range
Lightning Damaged Kenmore/Roper Range (F14-047).
Flash Burn to the Range Power Plug
Flash Burns to the Range Power Plug(F14-047).
Flash Burns to Wiring Harness Cover
Flash Burns to Wiring Harness Cover (F14-047).
Flash Burns to Wiring between the Wiring Harness Cover
Flash Burns between the Wiring Harness Cover and other Componets (F14-047).
Flash Burns to One of the Oven Wire Terminals
Flash Burns to one of the Oven Wire Terminals (F14-047).
Flash Burns where Wiring Harness made a Sharp Turn
Flash Burns where the Wiring Harness made a Sharp Turn. The Yellow Wire Insulation was ripped (F14-047).

Lightning Damage to an Avion Camper

This 1981 Avion Camper was parked under a tree. The tree was hit by lightning, and lightning flashed from the tree to the camper. Two holes, about half the size of dime, were present on the roof where lightning flashed to the camper. There was also melted aluminum at the waste tank door where the lightning current exited the camper. In line with where the lightning entered and exited the camper, is the door to the power converter. Although the power converter did not take a direct hit, it was damaged by induced lighting current. The changing magnetic field associated with lightning can induce electrical currents into nearby wires without coming in contact with then. Because the frequency of the lightning current is much greater than 60 Hz, the majority of it travels on the outer edge of the wire. Electrical engineers refer to this as the skin effect. High electrical currents induced into wires can heat the wire enough to change the color of the wire insulation, or it can melt or tear the wire insulation.

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1981 Avion Camper Hit by Lightning
1981 Avion Camper Hit by Lightning(F06-012).
Holes on the Roof Where Lightning Entered
Holes on the Roof Where Lightning Entered (F06-012).
Exit Point - Melted Aluminum on the Waste Tank Door
Exit Point - Melted Aluminum on the Waste Tank Door (F06-012).
Exit Point - Melted Aluminum on Edge Waste Tank Door
Melted Aluminum on Edge of Waste Tank Door (F06-012).
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Flash Burn Marks on Waste Tank Door
Flash Burn Marks on Waste Tank Door (F06-012).
Damaged DC Power Supply
Damaged Power Converter - 120 VAC to 12 VDC (F06-012).
Lightning Damaged Wires Inside Power Converte
Abnormal Black Marks on Wire Insulation (F06-012).
Wire Shadows Marks caused by Lightning
Wire Shadows Marks caused by Lightning (F06-012).

Lightning Damage to Backup Generator Crossover Switch

Lightning Damaged the Control Board on a Transfer Switch for a Backup Generator (Case No.: F21-036).

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Generator Transfer Switch and Control Board
Generator Transfer Switch and Control Board on the Door.
Location ofLightning Damage to the Generator Transfer Switch Control Board
Location of Lightning Damage to the Generator Transfer Switch Control Board.
Close UP of Lightning Damage to the Generator Transfer Switch Control Board
Close Up of Lightning Damage to the Generator Transfer Switch Control Board.
Damage to Surface Mount Integrated Circuit on the Generator Transfer Switch
Severe Damage to Surface Mount Integrated Circuit (IC) on the Generator Transfer Switch Control Board.

Lightning Fire and Damage to a Ground-Fault Receptacle

Lightning current entered the electrical system this home and caused a small attic fire (F21-047). The home was not properly grounded. Had the residents not been home and immediately called the fire department, this could have been a major fire. By the time of my inspection, an electrician had already made repairs. He left behind a Ground-Fault receptacle that he replaced.

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Outside of Lightning Damaged Home
There was no Observable Lightning or Fire Damage to the Outside of the Home.
Small Attic Fire caused by Lightning
Lightning current caused a small attic fire. Had the residents had not been home, this could have been a major fire.
Outside of GFCI Receptacle and Bus Bars
There was no Observable Damage to the Outside of the Ground Fault Receptacle or the Bus Bars.
Differential Current Transformer and Solenoid
There was no Observable Damage to the Differential Current Transformer or Solenoid.
GFCI Receptacle MOV (varistor)
There was no Observable Damage to the Metal Oxide Varistor (MOV) that should have suppressed the Surge and prevented Damage to the Electronics.
Lightning Damage ro Surface Mount PCB of a GFCI Receptacle
There were Lightning Flash Burn Marks on the Surface Mount PCB of the GFCI Receptacle.

Lightning Damage to Apple TV (3rd Gen) Power Supply

Lightning damaged the direct current (DC) power Supply in an Apple TV (Case No.: F19-025). The Metal Oxide Varistor (MOV) was NOT damaged, and the fuse did NOT melt.

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DC Power Supply in Apple TV 3rd Generation
DC Power Supply in Apple TV 3rd Generation.
Lightning Damage was on the Back Side of the Printed Circuit Board for Apple TV Power Supply
The Lightning Damage was on the Back Side of the Printed Circuit Board for Apple TV Power Supply.
Lightning Damage to Surface Mount Components in the Apple TV Power Supply
Close Up of Lightning Damage to Surface Mount Components in the Apple TV Power Supply.
The Fuse in the Apple TV Power Supply did NOT Melt
The Fuse in the Apple TV Power Supply did NOT Melt or Blow.

Lightning Protection System

In areas with frequent lightning, a lightning protection system should be considered. A lightning protection system consist of lightning-rods (air terminals) and equipotential bonding.

NFPA 780: Standard for the Installation of Lightning Protection Systems

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Lightning Struck the Chimney and Destoryed this Home.
On , Lightning struck a Chimney and Completely destoroyed this Home in Lafayette, LA (F11-007).
10 Lightning Rods on Adjacent House
The Adjacent House in Lafayette, LA had a Lightning Protection Sysem. 10 Lightning-Rods are depicted in this Photo (F11-007).
10 Lightning Rods on Adjacent House
Lightning struck the Chimney of this Home in Birmingham, AL and caused over $100K of damage to the electrical system (F14-045).