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Posted by CL (dnoyeB) Gilbert on July 11, 2005, 9:46 am
w_tom wrote:
> MOVs don't open the circuit. Even grossly undersized power
> strips that have vaporized MOVs still connect an appliance to
> AC mains. Where is this disconnection that Pop claims? It
> does not exist.
>
> A vaporized MOV operates outside of what the manufacturer
> has intended and designed. Pop, if he had used facts rather
> than post insults, would have first read those MOV datasheets
> rather than learn from a BestBuy salesman.
>
> Effective 'whole house' protectors install sufficient
> joules. The owner never knows a surge exists AND the protector
> remains functional. Power strips that are undersized will
> vaporize leaving the appliance exposed to that surge. Then
> the naive will recommend them and buy more useless protectors
> at tens of times more money per protected appliance.
>
> The naive will declare, "the protector sacrificed itself to
> save my computer." Protection already inside the adjacent
> computer saved that computer. The surge was too small to
> overwhelm internal computer protection. But the same tiny
> surge vaporized an undersized, overpriced, and ineffective
> protector. Why put sufficient joules inside a protector when
> less joules means Pop will recommend it?
>
> If MOVs worked as Pop claims, then removed MOVs (same as
> vaporized MOVs) would cause the power strip to stop working.
> Reality: even the OK light remains illuminated after all MOVs
> are removed:
> http://www.zerosurge.com/HTML/movs.html
> Why do power strips with vaporized MOVs still provide power?
> Because they do not operate as Pop has posted.
>
> Meanwhile code demands that all surge protectors not create
> flames even if operated beyond its specs. Pop instead tells
> us that "That surge ... was large enough to jump the gaps of
> the MOVs once they opened up" Therefore a fire is
> acceptable? When MOVs vaporize, the spark can continue
> jumping across the vaporized MOV. That can mean fire. MOVs
> are not designed to operate open circuited and are not
> designed to vaporize. MOVs that vaporize - go open circuit -
> can even create house fires. Why? Because the protectors was
> so grossly undersized; too few joules.
>
> Learn from what Rob Mills has posted. The last place you
> want a grossly undersized power strip protector is on a desk
> full of papers, in dust balls behind furniture, or on a rug.
> Some pictures demonstrate the problem with grossly undersized
> plug-in protectors:
>
> http://www.westwhitelandfire.com/Articles/Surge%20Protectors.pdf
>
> http://www.nmsu.edu/~safety/programs/gen_saf/surgeprotectorfire.htm
> http://www.ddxg.net/old/surge_protectors.htm
> http://www.ehs.washington.edu/LabSaf/surge.htm
> http://www.cob.org/fire/safety/surge.htm
> http://www.hanford.gov/lessons/sitell/ll00/2000-02.htm
>
> And finally: http://www.rbs2.com/fire.htm
>
>>A particularly horrifying fact is that many commercial surge
>>suppressors in the USA put the thermal disconnector and
>>varistor in series, so that — after the disconnector opens —
>>the vulnerable equipment downstream from the suppressor is
>>exposed to whatever voltage killed the varistor.
>
>
> Funny. That is not how Pop said they work. Funny. Pop
> would even call plug-in protector house fires acceptable when
> the surge is too large. Funny. He is so knowledgeable that
> he insults rather than provide numbers, science concepts, or
> citations. Worry about those grossly undersized power strip
> protectors as even Rob Mills demonstrates.
>
> Pop wrote:
>
>>===> Undersized how? They're rated for x joules, more
>>than that causes the MOVs to conduct, until they open
>>the ckt. If you mean undersized to protect against
>>monsrous surges, OF COURSE!! The sentence means
>>nothing.
>>...
>>
>>
>>>Rob Mills demonstrates, can even create a house fire.
>>
>>===> NO surge protector can protect beyond the number
>>of joules it's rated at, and it would very UNlikely to
>>have started a fire if nothing else in the house was
>>bothered. That surge, if it really happened, was large
>>enough to jump the gaps of the MOVs once they opened
>>up, and thus was capable of jumping many other gaps.
>>Sometimes though, a protector CAN sacrifice itself for
>>the equipment, which sounds like what happened, but ...
>>it wouldn't have started a fire unless it was sitting
>>inside a pile of tinder that sparks could have ignited.
>>The plastic would nto have melted or other equipment
>>would have been damaged. Black stuff only indicates
>>spark, not flame.
>>
>>> The effective protector earths a surge; and the
>>>homeowner
>>>never knows it happened.
>>
>>===> No, protectors do much more than that; they are
>>wye-connected varistors usually with inductive walls to
>>keep the lines within safe ranges of each other whether
>>it's earth or hot to neutral or ... and so on.
>>
>>> Protectors that provides effective protection are
>>>located
>>>close to earth ground AND are properly sized.
>>
>>===> What the hell do you mean by "properly sized"?
>>And what the heck does "close to ground" mean anyway?
>>
>>You have no idea what you're talking about, do you?
>>
>>This is called
>>
>>>a 'whole house' protector. Where it is located? Not
>>>on a
>>>pile of papers on a desk, or behind the furniture, on
>>>a rug,
>>>or within dust balls. Just more reasons why plug-in
>>>protectors (that cost so much money) are so
>>>ineffective.
>>
>>===> Wrong, proton breath; they are quite effective and
>>useful and are recommended for very good reasons. I
>>hope you aren't using any and that you shortly suffer
>>several power and phone line lightning hits within 5
>>miles of your home or less, preferably the transoformer
>>you're fed from. You're a moron in this area.
>> So, uhhh, just where is it located, by the way? Do
>>you even know?
>>
>>Pop
I agree with all stated here except the retributory insults to Pop.
Transformers have a way of mellowing out a surge. A surge typically has
to pass through a couple of transformers before it reaches a damageable
component.
A surge protector does not function like a circuit breaker. In fact
breaking the circuit can be worse as it can effectively create a
negative surge or an additional voltage spike.
The hardest work for a relay or a switch is breaking the current flow.
--
Respectfully,
CL Gilbert
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