Fozzy;643035 Wrote: > In this case grounding at the customers premises probably acts more to > protect the cable company's equipment and that of neighbouring customers > that it does to protect your equipment. If any wire enter your house without being earthed, then all household appliances (even the furnace) are at risk. That cable company wire is earthed so that a surge does not enter via their cable. All telephone wires (not just one) are earthed by a 'whole house' protector installed for free by the telco. Earthed also to protect all appliances.
But wires that most often carry surge currents into the house are AC electric. If you have not earthed all (typ. three) incoming AC electric wires using a 'whole house' protector, then no effective surge protection exists. Dr Standler discusses this in his book "Protection of Electronic Circuits from Overvoltage": > This situation could be resolved by the use of mandatory standards ... > At this time this book was written (1988), the author saw no hope of > such standards being adopted in the United States for overvoltages on > the mains. Assume two buildings are interconnected by an Ethernet cable. And that cable is not earthed at the service entrance of both buildings. Then a lightning strike to one building acts like a lightning rod connected to all computers inside the second building. Damage because that cable was not properly earthed where it entered each building. Every wire (all eight inside an Ethernet cable) must connect to earth. -- westom ------------------------------------------------------------------------ westom's Profile: http://forums.slimdevices.com/member.php?userid=39650 View this thread: http://forums.slimdevices.com/showthread.php?t=88797 _______________________________________________ discuss mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/discuss
