Quote Originally Posted by little_scrapper View Post
Why flat? Does the EMF produced by AC component of the strike cause the skin effect. If thats the case then I can understand why everyone is pimping the braided conductors (more surface area).
Science says blunt rods are significantly better than sharp pointed rods. But urban myths live on long after the science is discovered. Unfortunately most of us are only educated by advertising - much less knowledge comes from science.

Surges are not DC. Surges are radio frequency transients. Protection is always about impedance - not about resistance.

It was an old joke in engineering school. The DC transient. No such thing exists. Switched DC is a sum of sine waves (Fourier Series) - is not DC current. Lightning is about sine waves at many radio frequencies - is not DC current.

Braided wire does not have appreciable lower impedance compared to solid wire. To significantly lower impedance, each wire in the braid would be separated. Braided wire breaks down, corrodes, or fails faster. Any advantage in lower impedance is irrelevant compared to environmental damage.

Impedance is why a wire with sharp bends compromises protection. Impedance is why wire length (not wire thickness) is the relevant parameter. Why an effective protector must be located so close to single point ground. Why better protection means electronics separated from the protector. And why even splices compromise protection.

The fundamental concept. Lightning is conducted to earth via wooden church steeples. But wood is not a superior conductor. 20,000 amp lightning strike conducted by wood results in a high voltage. 20,000 amps times a high voltage is high energy. Church steeple destroyed.

Franklin simply earthed lightning rods. Rods do no protection. Protection is the earth ground connection. 20,000 amps through a conductive wire to earth is low voltage. 20,000 amps times a low voltage is low energy. No damage. Surge is harmlessly absorbed in earth.

All effective protection does that. Franklin solved lightning to earth destructively via a building. 'Whole house' protector solves lightning to earth destructively via appliances.

Essential to appliance protection is a low impedance (ie 'less than 10 foot') connection to single point earth ground. Better earthing means most energy dissipates outside. Less energy to overwhelm protection already inside every appliance. A protector - or a lightning rod - is only as effective as its earth ground. A lowest impedance (not resistance) connection.