OT - are there telco lightning protection guidelines?

[David Hamilton]

Be aware that if you add protection to your phone line, you can severally lower your modem connection speeds.





Mike Rambo extolled:
> 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
> _______________________________________________
> linux-user mailing list
> linux-user@egr.msu.edu
> http://www.egr.msu.edu/mailman/listinfo/linux-user