Re: Soon to arrive my HDTV

BDK wrote:
> In article <f443aecb-91e8-4745-9e76-e9eac2fa12b5
> @[EMAIL PROTECTED]
>, w_tom1@[EMAIL PROTECTED]
 says...
>> On Mar 30, 12:25 am, G-squared <stratu...@[EMAIL PROTECTED]
> wrote:
>>> No sir, you're spouting BS. It's dissipated as _heat_. You've never
>>> seen an overloaded MOV explode from too much energy? This is NOT to
>>> say you _may_ get a large neutral to ground spike but you _can_
>>> dissipate line to neutral and reduce the chance of failure. Remember,
>>> the bulk of the surges come from man-made problems like inductive
>>> kicks from motors powering up or down. Mother nature doesn't hit all
>>> that often at home and when she does, we'll all wish we hade your
>>> super ground system but I have to wonder how much induced voltage is
>>> generated from the intense current in the lightning itself. If it's
>>> magnetically generated inside the units, all the grounds in the world
>>> won't do diddly.
 >>>
A close strike can induce surges on wiring inside a house either with 
the wiring acting as a 'long wire' or a 'loop' antenna. Really close 
strikes are not common. The surge occurs downstream from entry 
protectors to the house, but the surges are relatively low energy. One 
of the places they can cause damage is on alarm wiring.

Nuclear EMP can cause damage directly in equipment (as in the TV drama 
Jericho). I am not aware that can happen with lightning damage to 
equipment that is disconnected from everything.
>>
-------------------------------------------
 >>
>> What happens when a protector is grossly undersized?  See these
>> 'scary pictures':
>>  http://www.hanford.gov/rl/?page=556&parent=554
 >>
The hanford link is about "some older model" power strips, and says 
overheating was fixed with a revision to UL1449 that required thermal 
disconnects. That was 1998. There is no reason to believe, from any of 
these links, that there is a problem with suppressors produced under the 
UL standard that has been in effect since 1998. No link even says a 
damaged suppressor had a UL label.
 >>
>> A protector is only as
>> effective as its earth ground.  No short earthing connection means no
>> effective protection.
 >>
The IEEE guide explains that plug-in suppressors do not primarily work 
by earthing and that earthing occurs elsewhere.

Both the IEEE and NIST guides say plug-in suppressors are effective.

Still *no source* from w_ that says plug-in suppressors are NOT effective.

Still no answers to simple questions - like -  if plug-in suppressors 
are NOT effective why do the only 2 examples of surge protection in the 
IEEE guide use plug-in suppressors???
>>
 >>
 >>
 >>
>> The effective protector does not explode. 
>
> What you say is all well and good, but I have had about a dozen MOVs in 
> protectors explode over the years. Most of them barely had anything 
> connected to them, except a VCR or Satellite receiver, hardly a huge 
> draw..the last one made a pretty loud bang when it "popped". I was about

> 6 feet away.
> 
The size of the connected load has nothing to do with failure of MOVs. 
You are talking about MOV failure, not circuit breaker trip?
 >
> I always though it was normal for them to explode.
> 
It is certainly NOT normal. If 12 exploded something else must be going
on.
Particularly with a satellite receiver, does the entry of the satellite 
wiring to the house have ground protection as required by the NEC (US)?
Is the ground connection to the same ground system as the power service/ 
phone/cable (also required by the NEC)?
Is the ground connection to the power service by a short length wire?

What was happening? Lightning?
Which protection element exploded?  Signal? MOV from H-N? H-G? N-G?
Were the protectors UL listed?  Bought after 1998?
What were the ratings?  (Suppressors with high ratings are readily 
available.)
All at the same location?  How far from service panel?

-- 
bud--