A friend who is an electrical engineer (heavy current) told me to earth my satellite dish and its fixing pole against lightning, using a thick copper cable (6 sq.mm) and an earth spike. He also said the earth cable must have gentle bends and no sharp bends where it fits around rooftop/wall edges etc. Does this have to do with increasing the impedance of the cable thereby reducing its effectiveness?

  • \$\begingroup\$ If you're going to the trouble to put in a ground rod or plate, you should consider going to 6 or 8 AWG or better. You could also put a lightning rod on the pole at an elevation higher than the satellite. Ideally the lightning rod provides a path to bleed power out of the charged air before enough builds up for a strike. Something to consider if you're going to the trouble of working on it anyway. In practice lightning arrest cables typically provide direct connection from lightning arrestor to ground grid, and they are bent as necessary to achieve install. \$\endgroup\$ – K H Dec 26 '18 at 22:14
  • \$\begingroup\$ That said, arrestor cables (and the conduit they are run in) are typically large enough that you wouldn't put a bend in with less than a 2 or 3 inch radius, more likely 6 or 8" radius due to 21mm or 27mm conduit. For lightning arrest minimal impedance is desirable, both to "bleed" the cloud well and also to minimize damage in case of an actual strike. For this reason you should likely minimise not just bend, but also cable length. \$\endgroup\$ – K H Dec 26 '18 at 22:20

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