Surge Protectors
in [Repair]
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From: sparky on 20 Jun 2010 22:04 " A protector is only as effective as its earth ground. So bud wants to discuss airplanes to avoid reality. Where are those manufacturer specs that claim protection from each type of surge? NIST and IEEE say why bud cannot provide them. A protector is only as effective as its earth ground. " Certain ignorant people here keep perpetuating this total LIE. I won't call them liars because I believe they are not doing it inttentionally, they just have no understanding of what they are talking about. This makes them very dangerous as they are spreading False information which may be read by someone who thinks it is actually true.
From: David on 20 Jun 2010 22:40 >>>> A MOV is somewhat like two back-to-back Zener diodes. >>>> It >>>> is >>>> a voltage clamp. >>> >>> no,it's not. it does not "clamp" the voltage. >>> >>>> You do not pass energy to ground, you pass >>>> current to ground just like you do with any load. The >>>> energy >>>> is totally dissipated in the MOV. > > Uh,"passing current to ground" IS passing energy to > ground. > >>>> >>>> David >>>> >>>> >>>> >>> >>> totally wrong. >>> Wiki has a nice article on metal-oxide varistor,I >>> suggest >>> you read it. >>> >>> -- >>> Jim Yanik >>> jyanik >>> at >>> localnet >>> dot com >> >> Jim, I am not going to get into a flame war over this >> topic. >> Maybe you should check this out: >> >><http://www.cliftonlaboratories.com/metal_oxide_varistor_(mov).htm> >> >> David >> >> > > http://en.wikipedia.org/wiki/Metal_oxide_varistor > > Varistors can absorb part of a surge. How much effect this > has on risk to > connected equipment depends on the equipment and details > of the selected > varistor. Varistors do not absorb a significant percentage > of a lightning > strike, as energy that must be conducted elsewhere is many > orders of > magnitude greater than what is absorbed by the small > device. > > -- > Jim Yanik This is my final say on this topic. In the quote above, you assume the section saying that "... energy that must be conducted elsewhere ..." goes to ground through the MOV. This is where your error resides. The energy is going elsewhere but being dissipated somewhere else completely such as blowing up a transformer. The article should also use the term dissipated elsewhere to make things clearer. You also assume that passing current is equivalent to dissipating energy. Current can *move* energy somewhere, but electrical energy is only dissipated when the current causes a voltage drop. A perfect ground will not have a voltage drop so that is not where the the energy is being dissipated. David
From: Jim Yanik on 20 Jun 2010 22:56 "David" <someone(a)somewhere.com> wrote in news:hvmjej$2ep$1(a)news.eternal- september.org: > > >>>>> A MOV is somewhat like two back-to-back Zener diodes. >>>>> It >>>>> is >>>>> a voltage clamp. >>>> >>>> no,it's not. it does not "clamp" the voltage. >>>> >>>>> You do not pass energy to ground, you pass >>>>> current to ground just like you do with any load. The >>>>> energy >>>>> is totally dissipated in the MOV. >> >> Uh,"passing current to ground" IS passing energy to >> ground. >> >>>>> >>>>> David >>>>> >>>>> >>>>> >>>> >>>> totally wrong. >>>> Wiki has a nice article on metal-oxide varistor,I >>>> suggest >>>> you read it. >>>> >>>> -- >>>> Jim Yanik >>>> jyanik >>>> at >>>> localnet >>>> dot com >>> >>> Jim, I am not going to get into a flame war over this >>> topic. >>> Maybe you should check this out: >>> >>><http://www.cliftonlaboratories.com/metal_oxide_varistor_(mov).htm> >>> >>> David >>> >>> >> >> http://en.wikipedia.org/wiki/Metal_oxide_varistor >> >> Varistors can absorb part of a surge. How much effect this >> has on risk to >> connected equipment depends on the equipment and details >> of the selected >> varistor. Varistors do not absorb a significant percentage >> of a lightning >> strike, as energy that must be conducted elsewhere is many >> orders of >> magnitude greater than what is absorbed by the small >> device. >> >> -- >> Jim Yanik > > This is my final say on this topic. In the quote above, you > assume the section saying that "... energy that must be > conducted elsewhere ..." goes to ground through the MOV. > This is where your error resides. The energy is going > elsewhere but being dissipated somewhere else completely > such as blowing up a transformer. The article should also > use the term dissipated elsewhere to make things clearer. feel free to edit it. > > You also assume that passing current is equivalent to > dissipating energy. No,that's what YOU assume I said. Wrongly. > Current can *move* energy somewhere, but > electrical energy is only dissipated when the current causes > a voltage drop. A perfect ground will not have a voltage > drop so that is not where the the energy is being > dissipated. HA,now you're talking about "perfect grounds".Sheesh. you don't know what you're talking about. BTW,when a lightning strike hits a ground,it dissipates it's energy -in the ground-. literally. It even makes a fulgurite.(fused earth) -- Jim Yanik jyanik at localnet dot com
From: bud-- on 21 Jun 2010 11:19 westom wrote: > On Jun 19, 12:25 pm, Jeffrey D Angus <jan...(a)suddenlink.net> wrote: >> What the plug-in suppressors rely on is the impedance (generally >> inductive) in the house wiring to limit the rise time of thesurgeuntil the circuit breaker (or fusable parts) have time to >> react by opening up. > > And why Bud will not discuss wire > impedance and earth ground. Poor westom's religious blinders prevent him from reading what gets written. I certainly have written about wire impedance in this thread. But if westom was not hampered by religious blinders he would read in the IEEE surge guide that plug-in suppressors do not work primarily by earthing. They work primarily by clamping the voltage on all wires to the ground at the suppressor. > > bud's citation Page 42 Figure 8 shows a plug-in protecting earthing > a surge 8000 volts destructively through a nearby TV. He hopes you do > not grasp the point in his IEEE citation. I hope everyone will "grasp the point" in the IEEE example. - The TV connected to the plug-in suppressor is protected. - "To protect TV2, a second multiport protector located at TV2 is required." > > So let's put numbers to it. Let's say the plug-in protector and TV > are 50 feet of wire from the breaker box. That means it is less than > 0.2 ohms resistance. And maybe 120 ohms impedance. So that protector > will earth a trivial 100 amp surge? 100 amps times 120 ohms means the > protector and TV are at maybe 12,000 volts. With minimal reading skills westom would have read that at about 6kV (US) there is arc-over at the service panel from bus to enclosure/ground - which is connected to the earthing electrode and neutral. After the arc is established, the voltage is hundreds of volts. The same thing happens at receptacles. This is a well established action for people who are familiar with surge protection. westom makes up a 100 amp surge on the branch circuit and 120 ohm impedance - won't happen together. > Why did the protector > earth that surge 8000 volts through the TV? And the lie repeated - 5th time? In the IEEE example - of how plug-in suppressors protect - the suppressor at TV1 causes absolutely NO damage to TV2. > > Why do telcos all over the world not waste money on bud's plug-in > protectors? Ho-hum - because telco switches are high amp, hard wired, and thousands of phone circuits would have to go through the plug-in suppressor. > > Learn that no protector works by absorbing energy. True of service panel and plug-in suppressors (but they absorb some energy while protecting). If you put a MOV across a relay coil, it protects by absorbing energy. > That is why the > protector too close to appliances and too far from earth ground can > even earth that surge 8000 volts destructively through a nearby TV. The lie repeated - 6th time? In the IEEE example the surge comes in on the cable service. westom has not explained how his service panel suppressor would provide any protection. That is because it would provide absolutely NO protection. With separated service entry points the IEEE guide says "the only effective way of protecting the equipment is to use a multiport [plug-in] protector." > A > majority only believe the advertising myths - that protectors > magically make hundreds of thousands of joules just magically > disappear. Only magic if you suffer from willful stupidity. > IOW a protector > is only as effective as its earth ground. Ho-hum - still never explained - why aren't flying airplanes crashing every day when they are hit by lightning? They must drag an earthing chain. Still missing - any reliable source that agrees with westom that plug-in suppressors are NOT effective. Still missing - answers to simple questions: - Why do the only 2 examples of protection in the IEEE guide use plug-in suppressors? - Why does the NIST guide says plug-in suppressors are "the easiest solution"? - Why does the NIST guide say "One effective solution is to have the consumer install" a multiport plug-in suppressor? - How would a service panel suppressor provide any protection in the IEEE example, page 42? - Why does the IEEE guide say for distant service points "the only effective way of protecting the equipment is to use a multiport [plug-in] protector"? - Why did Martzloff say in his paper "One solution. illustrated in this paper, is the insertion of a properly designed [multiport plug-in surge suppressor]"? - Why does Dr. Mansoor support multiport plug-in suppressors? - Why does "responsible" manufacturer SquareD says "electronic equipment may need additional protection by installing plug-in [suppressors] at the point of use"? - Why don�t favored SquareD service panel suppressors list "each type of surge"? For real science read the IEEE and NIST surge guides. Both say plug-in suppressors are effective. -- bud--
From: bud-- on 21 Jun 2010 11:23
Jim Yanik wrote: > "David" <someone(a)somewhere.com> wrote in news:hvmjej$2ep$1(a)news.eternal- > september.org: > >> >>>>>> A MOV is somewhat like two back-to-back Zener diodes. >>>>>> It >>>>>> is >>>>>> a voltage clamp. >>>>> no,it's not. it does not "clamp" the voltage. >>>>> >>>>>> You do not pass energy to ground, you pass >>>>>> current to ground just like you do with any load. The >>>>>> energy >>>>>> is totally dissipated in the MOV. >>> Uh,"passing current to ground" IS passing energy to >>> ground. >>> >>>>>> David >>>>>> >>>>>> >>>>>> >>>>> totally wrong. >>>>> Wiki has a nice article on metal-oxide varistor,I >>>>> suggest >>>>> you read it. >>>>> >>>>> -- >>>>> Jim Yanik >>>>> jyanik >>>>> at >>>>> localnet >>>>> dot com >>>> Jim, I am not going to get into a flame war over this >>>> topic. >>>> Maybe you should check this out: >>>> >>>> <http://www.cliftonlaboratories.com/metal_oxide_varistor_(mov).htm> >>>> >>>> David >>>> >>>> >>> http://en.wikipedia.org/wiki/Metal_oxide_varistor >>> >>> Varistors can absorb part of a surge. How much effect this >>> has on risk to >>> connected equipment depends on the equipment and details >>> of the selected >>> varistor. Varistors do not absorb a significant percentage >>> of a lightning >>> strike, as energy that must be conducted elsewhere is many >>> orders of >>> magnitude greater than what is absorbed by the small >>> device. >>> >>> -- >>> Jim Yanik >> This is my final say on this topic. In the quote above, you >> assume the section saying that "... energy that must be >> conducted elsewhere ..." goes to ground through the MOV. >> This is where your error resides. The energy is going >> elsewhere but being dissipated somewhere else completely >> such as blowing up a transformer. The article should also >> use the term dissipated elsewhere to make things clearer. > > feel free to edit it. >> You also assume that passing current is equivalent to >> dissipating energy. > > > No,that's what YOU assume I said. Wrongly. > >> Current can *move* energy somewhere, but >> electrical energy is only dissipated when the current causes >> a voltage drop. A perfect ground will not have a voltage >> drop so that is not where the the energy is being >> dissipated. > > HA,now you're talking about "perfect grounds".Sheesh. > you don't know what you're talking about. I agree. The vast majority of energy in a lightning strike is passed on to the earth. Assume a surge of 10,000A on a service wire (maximum that has a reasonable probability), a very good resistance to earth of 10 ohms and a duration of 100 microseconds. If I am multiplying right that is 100,000 joules dissipated in the earth. If you had a service panel suppressor with UL let through voltage of 330V (measured at a specified current much lower than 10kA) the actual voltage across the MOV might be 500V and the energy dissipated for the same surge would be 500 joules. Most of the energy that was available at the cloud is dissipated on the trip down - in heat, light, sound.... In about any lightning strike there are multiple paths to earth - multiple utility earthing points, multiple houses, .... > > BTW,when a lightning strike hits a ground,it dissipates it's energy -in the > ground-. literally. Nice example. > > It even makes a fulgurite.(fused earth) > |