OT - are there telco lightning protection guidelines?

[Mike Rambo]

Tim Schmidt wrote:
> 
> I have similar problems at my location...  3 or 4 modems, a satelite
> reciever, etc...  phone line surge supressors are the best bet.  They're
> about $5 - $15 and instead of the $100 motherboard getting blown, a little
> fuse in the surge supressor gets blown.
> 

Thanks to all who responded. One thing I left out originally is that
this machine _is_ on a UPS. It's not a model with built in protection
for the telephone line though - guess I better add that. I do have a
telephone line surge protector on my upstairs modem and if I forget to
unplug it I can count on replacing the fuses if there is lightning
anywhere in Michigan it seems.

I've put in over 20 years now repairing electronic equipment. I have
definitely seen cases, and often repaired the resulting damage, where
lightning came in on the antenna line for tv, vcr, or stereo receiver
equipment. I've also seen cases where there was definite damage to power
supplies where the surge came in on the AC power. I could probably count
the number of cases of damage from both of the above scenarios and might
not even have to take off my shoes - hands would do. Damage from
telephone connections is an entirely different story. I spent a few
years a decade or so ago doing nothing but telco equipment repair (ans
machines, phones, dialers etc.) for the company I worked for at the
time. I have seen score upon score of equipment damaged where the surge
clearly came in from the telephone line. Some of the telephones that
were damaged had no connection to the outside world other than the
telephone line (unless you count the hand that held them) although it is
true that the predominant number of cases are in situations where there
is both telephone and power, especially ground, connections. My modem
the other day, a US Robotics external, has only a wall wart for power.
The adapter is fine. The modem itself still works - relay clicks and
tries to connect to the line but can't because all the low value
resistors in the line interface are blown. It definitely frustrates me
that all the telco says is that it isn't them. I've literally got black
marks on the counter where the answering machine got nailed and it came
through some vent slots on the bottom of the case. This is the second
time where I've had to replace the phone line running from the wall to
the device because the ends are black and charred. I've also got a
modular coupler that has the wires inside melted. The telco can say all
they want that the surge came from somewhere else - but I know better
and have the evidence to prove it.

> The problem isn't so bad at my house now, but I did just have a modem blown
> (crappy $0.50 winmodem)...   it used to be that anytime there was lightning
> within 5 miles it would zap our house.  Phones and answering machines have
> never been affected, but all modem-like devices have (hardware + software
> modems, satelite reciever (embedded hardware modem)).
> 
> Explanations?

I've never gotten anything from the telco other than to say "it's not
us". As much as I usually hate government intrusion and regulation I
wish there was some way to know whether the telco is doing all they can
do to help the situation - they sure charge me enough every month just
to provide a dial tone.

Thanks to all.


-- 
Mike Rambo
mrambo@lsd.k12.mi.us