Re: is x10.com dead?

["Jeff Volp" <JeffVolp@xxxxxxx>]

"Marc F Hult" <MFHult@xxxxxxxxxxxxxxxxxxxxx> wrote in message
news:1onb02h43ejn59qd3qlc7l3voo52qclla4@xxxxxxxxxx
> On Wed, 01 Mar 2006 16:43:27 GMT, "Jeff Volp" <JeffVolp@xxxxxxx> wrote in
> message  <PakNf.482883$qk4.116787@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>:
>
> How on earth (pun intended) does being coupled to power lines that stretch
> from your house to the power plant afford you with "some measure of
> protection" ?
>
> It is precisely because RS-485 is readily isolated using optical couplers
> that RS-485 is an excellent and common choice for what you want to do.

The ADI modules do not include opto-isolation.  I had considered using
opto-isolated SSRs at the output of the SECU16, but the Rain8 was a simpler
solution.  Opto-isolators are only good for a couple KV, and I'm concerned
about high induced voltage in a relatively high impedance circuit.  That's
what took out part of our alarm system at the other house.  The bolt itself
hit a tree across the driveway from the house and blasted a hole in the
ground near the trunk.  The powerlines were underground, and nothing at that
house was ever effected by transients on the AC line. A similar condition
exists here.

If a close strike does induce high voltage in the switched 24V line, that
could take out the irrigation controller.  But the powerline and whole house
surge protector should dissipate the induced energy better than that 485
link back to the Ocelot.

Like I said earlier, all bets are off if there is a direct strike.

Jeff