For those who are interested in things electrical...
I trudged through the snow and removed the connection I had put between the
ground and neutral bars in the tower subpanel and connected the surge
suppressor wire to the ground bar (which is in turn connected to the tower
ground.) I believe the panel is now code compliant, although the surge
suppressor wiring is not what the manufacturer recommended. However, the
device (Siemens QSA2020 Type QP Circuit Breaker and Secondary Surge
Suppressor) is really designed to protect devices connected to the main
panel from surges coming in from the power lines. I believe their theory is
that since the neutral and ground are normally connected together at the
main panel, it makes sense to connect the suppressor to neutral -- that way,
they shunt surges to both the house ground and service ground. I suppose
that's a good idea if the house ground isn't so good. Note that Polyphaser's
panel protectors list "Shunt to ground, not neutral" as one of their selling
points.
My particular application, in which I'm using the device to suppress surges
from nearby (not direct) hits, and keep them from travelling up the AC lines
to the house, would seem to call for wiring the supressor a little
differently. As long as it's code, which I believe it is, I'm comfortable
with it.
Protection from a direct hit, as some have pointed out, would take something
with a rating of many kiloamps. I might put some 4kVA MOVs on the AC leads
in the subpanel for more protection. I've heard rumblings that MOVs can be a
fire hazard -- anyone know anything about that? By the way, Polyphaser makes
a unit designed to protect AC lines against surges originating outside.
Looks like it's designed to mount on or next to a towerand I would guess
it's used to protect against surges induced in tower lighting conductors.
It's rated 45KvA per phase and costs over a grand. With only 6.5kVa of
protection on the rotor and tower motor control lines, seems like MOVs in
the subpanel would be more appropriate for me.
BTW, for those who are interested in the issue of my ground electrode being
50 feet from the house, a reflector user pointed out to me that the exterior
meter panel mounted next to the pole (where the electrode is located) is the
real service entrance. The basement breaker panel, which I thought was the
service entrance and main panel (and, in fact, it was the main panel prior
to the remodelling), is actually a subpanel now. Sure enough, I pulled the
cover off the basement breaker panel and found that the electrician had
disconnected the ground and neutral bars, as appropriate for a subpanel.
Given that the electrode is out by the meter panel, I'm sure they connected
the ground and neutral inside that panel.
I think it's all code now. Thanks to those who supplied good advice.
73, Dick, WC1M
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