** Reply to message from "Lewis G Rosenthal"
<os2-wireless_users@2rosenthals.com> on Wed, 03 Feb 2010 22:33:54 -0500
> Yes, I've heard horror stories of these things. Unfortunately, without
> good a arrestor, anything connected to the bus is a potential casualty.
> Good warning for all to heed. ;-)
I shudder every time I think about this kind of crap. In case you've never
fought it, you have to consider just what you have that COULD come on at the
instant power is restored. Take the case where the refrigerator, furnace, TV,
and lights (especially florescent!) come on at once. Nearly all are inductive
loads and grounded through #12 or even #14 wiring, including earth grounds so
figure on Murphy's Law. Inrush currents easily can be as high as 20x the steady
state load so inductive spikes are really high. At high risk locations I have
often gritted my teeth and gone to a motor-generator isolation setup. Those
itty-bitty surge suppressor strips are like a Band-Aid on an amputation. I
have all my computer stuff on battery backup units and those feed off a single
40 amp isolation transformer built to snub incoming surges which also gives me
a relatively "soft" restart (couple of hundred bucks new) but it's still a crap
shoot.
The cheapest and easiest thing you can do to minimize the en evitable damage is
to double check all your earth grounds. Around here, we have to drive at least
an 8' rod . The other thing you can do is to turn off the refrigerator and
such so that there is minimal load on the feed when power does come back on -
but how do you manage that in the middle of the night or while you're at work?
The utility company here tried selling me their "whole house protection"
system. That protects me from the line but doesn't do squat for the spikes
induced inside the house wiring. The best (and most expensive) home system I
ever saw was one where the service panel had humongous relays and timers that
sequenced each breaker in the panel back on line with a short delay between
each loop being reconnected.
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