The first problem with braid is that the stuff forms a coating of copper
oxide around each strand that is nonconductive. This coating makes each wire
like a individual conductor with a resistance according to its gage. Now think
of the flexing due to vibration, heat cycling, or any other thing which will
cause the strands to rub against each other thus breaking the copper oxide
surface. The crossover points of the braid will be alternatively be conducting
and then reoxidizing to nonconducting state. This makes all the strands at
different resistances which when the 20,000 to 200,000 amp surge hits them will
cause some of them to take more of the current than others and vaporize. An
avalanche effect occurs and you have meltdown and arcs.
Second we have the idea that all the current will travel on surface with the
skin effect. This is true for normal current amounts but at the current levels
of lightning there are not enough free electrons at accommodate the current
flow and the conductor depth comes into account. If not enough depth is
available the current has to flow outside of the conductor in a arc as there is
no where for all those electrons to go.
The use of braided strapping to protect ammunition was to prevent a static
discharge from detonating the charges not the high current of lightning. In the
workers minds they thought it was for lightning but all you can do with
lightning is shunt the current, not stop flow. Even if you shunt 99% of current
there is enough voltage to arc at even micro amps which is enough to make
fireworks out of your munitions. The only safe place was inside of conductive
box with lid closed. (i.e. ammo boxes, metal lined bunkers, etc.)
That leaves us with either large stranded (each strand #12 or larger) or
solid conductors. Even solid has enough flex to allow a fold-over to work if
you disconnect(or never use ) the ground opposite the hinge.
Save your braid for your indoor station ground applications.
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