"Tie A Knot In It!" 
 Rusty - 1/22/04 

 


Ed Note: Rusty emailed this and I thought it would be interesting to others. 


While a warranty for surge suppressors and UPSs is fine, prevention is better. 


Years ago, a Navy electronics technician reasoned (rightfully, as it turned out) that the major source of fried electronics was from the surge current (not voltage), and that it created an accompanying magnetic field. He thought that if the magnetic field could be suppressed (or better, reversed), the surge current could be neutralized. 


His solution was simple - in all wires - power, net, modem, etc. he tied a simple knot in each cable. A few months after, a major lightning storm swept through the area (Washington, DC). The Army and Air Force lost a lot of equipment. The Navy, none. 


Tie a knot in each cable. I implemented this in our office about fifteen years ago. We took a direct lightning hit on our phone - while it fried the telco's box, we lost nothing. 


Incidentally, a lightning strike can cause more damage with an indirect hit than a direct hit. One of my Navy Reserve officers was the Superintendent of Electrical Services at Tampa International Airport, the first with "Totally Electric" terminal systems. The "People Movers", electric shuttle cars, would frequently fail during a lightning storm; the breakers (700 A) would either fail to trip or fuse closed. 


The cause was that the lightning strike created a rising-falling magnetic field - exactly what induces a current in a conductor. So the airport, during a storm, became an huge generator! The current was generated downstream of the supply breakers. 


Rusty