Bob wrote:

karsan wrote:


It is dangerous to have more than one surge protectors in you home I
have 3 surge protectors running in my home.


I have a whole house "protector" at the electrical panel and several
smaller units scattered throught the house. I have had several
lightning hits in the near vicinity and have never had electrical
damage. But I have lost 4 TV's from lightning coming in on the cable -
all damaged in the tuner sections rather than power sections. And I
have had computer modems fry from surges on the telephone line. So
from that, I deduce the whole house unit is doing it's job, but the
others are questionable.
Bob


Plug-in surge suppressors for cable TV need to have a port to include
both the power and cable TV. The multi-port surge suppressor will clamp
all voltages on power and signal wires to the common ground at the
suppressor. The IEEE guide at
http://www.mikeholt.com/files/PDF/Li...ion_May051.pdf
explains this quite well. It says the cable center conductor can be 4000
volts with respect to the shield. A plug-in suppressor will clamp this,
likely with a gas discharge tube. A bigger problem is if the cable
entrance ground block is not near, and connected with a short wire, to
the power service earthing conductor. That is also protected by a
multi-port plug-in surge suppressor and is illustrated in the IEEE guide.

Similarly, a plug-in suppressor for a computer with phone connection has
to have ports for both power and phone line.

bud--