Amazing!
Gary Schafer wrote:
>Some may be surprised upon opening up one of those whole house
>protectors to find that most are nothing more than a can filled with
>sand and a heavy duty spark gap inside. The sand is there to quench the
>arc after the surge is over. They do work though.
>
>73
>Gary K4FMX
>
>
>Jim Brown wrote:
>
>
>>On Thu, 29 Sep 2005 14:52:11 -0500, Dave NØRQ wrote:
>>
>>
>>
>>
>>>I've never had a problem with it -- no RFI from it, and it has never acted
>>>up, even with 1kw of RF quite close to it. Nor have I had any equipment
>>>damanged by lightning --
>>>
>>>
>>It's important to understand what these devices do. These "whole house"
>>units are simply BIG MOV's that attempt to conduct the surge to "short it
>>out." In doing so, it must GO somewhere -- that is, current flows in some
>>complete path. Remember that the neutral is bonded to ground at the service
>>entrance, so there is no need for a protector between neutral and ground. A
>>line to ground protector conducts the surge to ground, so when a surge hits,
>>it will raise the potential of the safety ground (and neutral bus) by an
>>amount equal to the IZ drop between the panel and whatever lightning thinks
>>"earth" is. When you say "line-to-line," I assume you mean across the 240
>>volt secondary of a 120-0-120 circuit.
>>
>>
>>
>>
>>>but then, all the electronics plug
>>>into "real" lightning protectors (usually TrippLite) before plugging
>>>into the wall
>>>
>>>
>>Your definition of "real" in this case is flawed. Nearly all AC line
>>"lightning protectors" are nothing more than MOV's connected as noted above.
>>When they take a hit, they shove the surge into the equipment ground wire at
>>the outlet where they are plugged in, raising the potential at that outlet
>>in the presence of a surge. If equipment plugged into a "protected outlet"
>>is connected by low voltage wiring to equipment plugged into another un-
>>protected outlet, or even a DIFFERENT protected outlet, there can be large
>>potential difference between outlets that can blow up equipment. Thus,
>>typical power-strip MOV protectors are NOT "real" protectors.
>>
>>The "real thing" includes 1) a good whole house protector and/or 2) a
>>SERIES-mode protector like those that SurgeX makes. I use SurgeX boxes, and
>>plan to add a "whole house" unit at the service entrance.
>>
>>And, as has been pointed out on several occasions, it is critical that other
>>lines (telco, antennas, etc.)that can bring lightning into the house be
>>bonde and/or protected AT THE SAME POINT as the power line. Tom Rauch has
>>pounded on this for quite a while, and he is right on. That's often a lot
>>more difficult in some installations, but it's the right way to do it.
>>
>>Jim Brown K9YC
>>
>>
>>
>>
>>------------------------------------------------------------------------
>>
>>_______________________________________________
>>
>>See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
>>Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
>>questions and ask for Sherman, W2FLA.
>>
>>_______________________________________________
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>>TowerTalk@contesting.com
>>http://lists.contesting.com/mailman/listinfo/towertalk
>>
>>
>
>
>
>_______________________________________________
>
>See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
>Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
>questions and ask for Sherman, W2FLA.
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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