Hi all,
Getting ready to put my ground system in shortly but will be shopping
for Polyphasers, etc at Hamvention next week.
Here's what I have. One 70' crank-up tower about 5 feet from the back
wall of my house. I've driven in a bunch of ground rods ~16 apart
(most are down all 8', some only 5 feet due to rocky soil, however)
going around my house on 3 sides. The fourth side is a paved
driveway, so that's not happening any time soon. It will eventually
connect to the service panel once I can get an electrician to come by
and hook it up, per NJ code.
I also have a bunch of Cadweld one-shots for AWG-4, but I haven't
purchased the wire yet. I'm guessing AWG #4 solid is the right choice
for this application? Given copper prices, 2-gauge is too expensive.
Questions:
1) How far below ground should I run these wires? I'm just using
hand-tools to trench, not a ditch-witch, so the plan was about 3 or 4 inches.
2) Polyphasers. This is a big question mark. Most things I've read
say to mount 'em all on a single-point panel inside the house,
strapped with a 2" or 3" copper bus to a ground rod outside the
house, which in turn is connected to the ground rod system. I 've
seen lots of pics online of polyphasers outside, in a NEMA box on
a tower leg, others saying I should have them physically connected
to the tower and the top and bottom, AND inside the house on the SPGP
panel, etc.
3) TVSS (transient voltage surge suppressors): Yes? No? Maybe??
Guys, am I over-thinking this or over-engineering this project for a
70; crankup?? I've got 3 trees higher than that on the property, as
do most of my neighbours, 250kV transmission lines at the end of the
street and a 20 year history of never taking a direct hit at this
house (100' tower by the previous owner with one ground rod and 4 GA
round green wire). the only lightning hit that did anything came in
on the power line as a surge that cooked my motherboard on the radio
PC, despite an APC UPS.
I'll be at the lightning panel in Dayton next week (probably asking a
lot of questions afterwards, too), but can always use more guidance.
Cheers,
Peter,
W2IRT
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