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Robert H. Hanson LAN/WAN Consultant - Internet Service Provider
Otis Orchards, Wa. Cutting Edge Communications www.cet.com
(509) 927-9541 finger: info@cet.com or email: roberth@cet.com
On Mon, 16 Sep 1996, Charles Scott wrote:
>
> Matt:
> Actually, the ONLY good way to protect your equipment IS to tie all
> your grounds together at one point. This is called (rather obviously) a
> "single point ground window". The intent is to prevent current from going
> through your equipment and is most important whenever you might be
> suseptable to nearby or direct lightning.
> The way it works is that all connections to your equipment come across
> a "ground window". This is in reality some adequate conductor, often a
> copper plate, to which the power line and phone line surge arresters are
> bonded. It's also important to bring any serial, printer or other I/O
> lines which go to other equipment, across that same window. If all of
> your computer equipment, including any terminals or other devices have
> their signal and power lines come back through that ground window, you
> can survive a direct lightning stike on your facility without loosing any
> equipment. Also, if you have your UPS on the equipment side of the
> ground window, your system may even continue to function without any
> interruptions during such a strike (although you may loose outside
> connectivity).
> Think of it this way. Electricity needs a complete circuit. If your
> equipment is in the middle of a completed circuit (sitting between the phone
> lines and the power lines), then the current will be going through it. If
> your equipment is hanging on the end of a ground window, and nothing is
> connected from your equipment to anywhere but the ground window, then you
> have no such current.
> Needless to say, there's a lot more to it that this, but it's the basic
> idea. This is the approach which broadcast and communications facilities
> use to protect their equipment, and believe me, those towers really get
> hit!
>
> Chuck
>
>
> On Mon, 16 Sep 1996, Matthew S. Crocker wrote:
>
> > > I'm a big fan of Panamax.
> > > If you get the Panamax TowerMax and the Co4x4 ( dont quote me on that
> > > number. the 4x4 is an 8 jack RJ11 surge supressor 4 lines in 4 lines out
> > > ) you can also get the CO-T1 ( again, dont quote me on that ) that protect
> > > two T1 lines. All of these have Panamax's $5 Million dollar lifetime
> > > equipment protection warranty. Unfortunatly it gets Bulky real quick but
> > > I haven't found a more dense solution yet.
> >
> > Remember,
> >
> > Surge Suppresors mean nothing if they are not installed properly.
> > Remember to ground them properly. Also don't tie all your grounds
> > together, A surge could come in through the phone line, hit the surge
> > protector which will channel it to ground. The surge will then go
> > through the ground wire and hit the equipment in the power supply.
> >
> > -Matt
> >
>