It Could Have Been Worse…

As a post on Flickr describes, “Lightning struck my [radio antenna] tower, and while most of it went to ground through the tower, a bit of it came down the disconnected coax that was in the attic.” While damage to the building’s electrical system and equipment was significant, the building was not destroyed and there were no injuries. But it could have been worse….

Black soot on electric outlet was caused by smoke resulting from lightning damage.

…The sparks and charring caused by the lightning could have ignite a major conflagration. These images were taken by Mark Taylor, a professional photographer from Rockville, MD. He explains:

“Every GFI outlet in the house tripped. Some of the breakers tripped, both 120V and 240V. The base for the cordless phone will charge the handset, but it’s otherwise dead. The cable modem will not power up at all. The cable box (for the TV) powers up, but cannot communicate with the cable company or receive any channels. The subwoofer for the Bose Acoustimass 15 is dead. The HVAC unit upstairs will not run, even in “fan” only mode. All the power going in is good, must be a blown control board (though it looks OK)… The microwave door was blown open (interesting that it still works, though!) About 15 minutes after the strike, the smoke detectors went off. Hedgesville Volunteer FD came out and used the FLIR to determine that there was no fire.”

“The exit wound on the coax… near the damaged HVAC unit,” shows where the lightning surged out of the cable sparking a small fire that could have become a larger disaster. (Circle added to original image.)

This arc damage to white cable where it enters the HVAC unit, is probably what energized the HVAC unit and knocked it out of service.

“The HVAC unit took most of the hit, melting some of the insulation on the ductwork.”

According to the post, “The tower WAS properly grounded with a commercial ground rod.” This demonstrates that ordinary grounding is not sufficient to protect against lightning. Radio antenna’s aren’t the only adjacent conductive objects that can “invite” lightning into a building. A nearby tree, a metal dog run, underground dog fence, pipes from wells, security cameras and other appurtenances can be the place where lightning attaches to the earth and then flows into nearby buildings.

To learn more about whole-building lightning protection systems for amateur radio operators, click here.

Photos used in accordance with a Creative Commons 2.0 License.