How long would a piece of strut (kindorf, unistrut..) have to be, when partially enclosing a grounding electrode conductor, to increase the grounding impedance to, say, 1 Ohm? Is the air gap so large that for all practical purposes the impedance is not affected by the strut?
Don't know. I would start by assuming that it is just a mild steel channel about 3/32" thick with dimensions of 1-7/8" for the three sides, and an air gap of maybe 1".
That was my initial assumption too. But then I got to thinking that since there IS a complete magnetic loop (though with a huge air gap that creates a reluctance nearly equivalent to just air) then there might be some way that there would be a choking effect. I just don't know how to figure the inductive reactance based on a magnetic circuit's characteristics..except for the text book examples for constructing filter coils. I don't know if there has to be eddy current paths along with the magnetic loops in order for there to be a large inductive reactance. Logic informs me that since there can be inductive reactance for even a straight piece of wire, then partially enclosing it in strut would certainly increase that reactance..but by how much?
