Wes Attaway (N5WA) wrote:
> The prior comments indicate that having MOVs at the service entrance is the
> way to go to get "whole house" protection. There are a number of commercial
> products available. I use the following, and have had excellent results:
>
Something we have to remember that is often taken for gospel and that is
the whole house rising to a given voltage together, which isn't quite
true as it's phrased and isn't true at all in some older homes.
The entire house does not rise and fall to the same potential at the
same time! BUT if all is wired properly the ground, neutral, and hot
along with telephone and data lines "at any given spot" (or location)
rise and fall together (more or less) . However the potential between
this point and one on the other side of the house might be several
thousand volts. An important point though is that when "induced voltage"
from a nearby strike is taken into account there may be substantial
differences between the different wires.
73
Roger (K8RI)
> These are Cutler-Hammer products and model numbers:
> CHSPMAX (AC power lines)
> DHW4PT (4 Telco lines)
> DCXCAB2 (2 cable/sat coax lines)
>
> ------------------ Wes Attaway (N5WA) ------------------
> 1138 Waters Edge Circle - Shreveport, LA 71106
> 318-797-4972 (office) - 318-393-3289 (cell)
> Computer Consulting and Forensics
> -------------- EnCase Certified Examiner ---------------
>
>
> -----Original Message-----
> From: towertalk-bounces@contesting.com
> [mailto:towertalk-bounces@contesting.com] On Behalf Of HansLG@aol.com
> Sent: Friday, March 19, 2010 6:31 PM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] Shack wiring
>
>
> Hi Jim,
>
> I still don't get it (maybe because I am dumb). At my service entrance is
> a protector that connects has two MOVs, one from each leg to ground. Ground
>
> in this case is the same as neutral At the water pump is also a protector
> that has MOVs frm the two legs (the pump is a 240 V pump) and ground. In the
>
> shack I have a protector that connects MOVs from neutral AND the hot 120 V
> leg to ground. It also incorporate a protecting circuits for my phone, it
> has two gas discharge tubes between the line and ground.
>
> Should I disconnect al MOVs that are connected to ground ??? As I wrote to
> you earlier, my house has had two registered lightning hits (and possible a
> couple of more we don't know about) and everything survived.
>
> Can anyone describe the failure mode that makes the MOV from the hot leg to
> ground bad?
>
> Hans - N2JFS
>
>
> In a message dated 3/19/2010 1:33:50 P.M. Eastern Daylight Time,
> jim@audiosystemsgroup.com writes:
>
> Hi Dick,
>
> I don't know "the Soft-Start kit" or it's application, so I can't comment
> beyond
> what I've said here. But MANY products are designed with serious
> engineering
> mistakes. The "pin 1 problem" is a glaring and very common example -- it
> causes
> hum, buzz, and RFI. Putting an MOV between line and safety ground is
> another one
> -- it can blow up equipment! The only safe place for an MOV (or other
> shunt-mode
> protector) in the power system is at the main service entrance where power
> comes
> into the building from the street. This is the so-called "whole house"
> protector,
> and it's a very good idea if done well.
>
> 73,
>
> Jim K9YC
>
> On Fri, 19 Mar 2010 17:22:37 +0000, RICHARD SOLOMON wrote:
>
>
>
>> Are you saying we should not use the ones that come with the Soft-Start
>>
> kit ??
>
>
>> 73, Dick, W1KSZ
>>
>
>
>>> From: jim@audiosystemsgroup.com
>>> To: towertalk@contesting.com
>>> Date: Mon, 15 Mar 2010 22:50:45 -0700
>>> Subject: Re: [TowerTalk] Shack wiring
>>>
>>> On Mon, 15 Mar 2010 21:34:10 -0400, hanslg@aol.com wrote:
>>>
>>>
>>>> A good surge protector has three MOVs, one from each leg and one
>>>>
> between
>
>>>> the legs.
>>>>
>>> WRONG! An MOV from Phase (hot) to Ground (Green Wire) is more likely to
>>>
> BLOW
>
>>> UP equipment than protect it. To understand this, see my earlier post
>>>
> on
>
>>> this.
>>>
>>> 73,
>>>
>>> Jim K9YC
>>>
>
>
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