Choosing surge protectors

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Elrast
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Choosing surge protectors

Post by Elrast » Sun Mar 11, 2012 9:26 pm

Doing research on surge protectors, would like any comments / experience please:

* Novaris plug in series - uses a 3 stage MOV / LC filter / MOV scheme; relatively expensive, not easily available to everyday consumers
* Eaton POD - uses a 3 stage MOV/ LC filter / MOV scheme; around $40 ish, seems decent on specs
* SurgeX - detailed design not disclosed; $500+ easily; consumes power. IMHO, the product and marketing sounds a bit like Monster cables... happy to be proven wrong
* Isobar Tripplite - multistage incl. LC filter, apparently has integral noise filtering. Availability of 230V version seems limited.
* Ferroresonant transformer - too big, too expensive, waste too much power
* Thor smart filter duo C2 - $100, seems to have some reactive components in there w/ the MOVs. Is it worth it?

Re: connected equipment warranty - seems to have so many conditions on them that its not worth accounting for it in the selection process. i.e. ignore it completely

Re: MOV failures. MOV failing open circuit seems to be the main issue, which is not detectable. Is there a recommended replacement schedule? every 3 years?

Thanks

m0002a
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Re: Choosing surge protectors

Post by m0002a » Sun Mar 11, 2012 9:58 pm

Excuse my lack of expertise, but isn't a UPS (with built-in surge protection) much more important? Seems like most damage to a system (especially damage to disk which can make a system un-bootable) is likely to occur when there is a power outage, and most UPS units provide adequate surge protection.

Elrast
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Re: Choosing surge protectors

Post by Elrast » Sun Mar 11, 2012 10:18 pm

Bit of an unusual case here - I've got a UPS that's already in use - but its a battery charger. Not sure how much protection was built into the charger itself.

Looking to enhance system protection by preventing overvoltages from getting into the battery charger (UPS).

ces
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Tripp Lite Line Conditioners

Post by ces » Sun Mar 11, 2012 10:32 pm

I have been using Tripp Lite Line Conditioners
http://www.tripplite.com/en/products/pr ... riesID=838

It is supposed to provide not only surge protection, but also condition the electricity. If there is a brown out it will increase the line voltage and if line voltage is running a little to high, it nudges it down.

"Premium automatic voltage regulation (AVR), power conditioning and AC surge suppression"
"Maintains regulated 120V nominal output over an input range of 89 to 147V"
"Prevents equipment damage and power related performance problems for computer accessories, printers, home theater equipment, a/v components and other sensitive electronic devices. Network-grade AC surge and EMI/RFI noise suppression."

Is using line conditioners smarter than using just a surge protector.... or is it dumber?

I wonder how long they last and if they eventually wear out. Does anyone have any opinions on this?

Elrast
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Re: Choosing surge protectors

Post by Elrast » Sun Mar 11, 2012 11:07 pm

Line conditioners have some smarts in them to adapt to changes in line voltage.

Would think that a "pure" line conditioning function does not have surge protection and vice versa. That being said, I'd doubt there's any commercially available piece of kit that only does line conditioning. At the minimum I'd expect it to have a MOV in there, and if you're lucky some other low pass filtering elements as well. But exactly how much surge protection circuitry is integrated into the line conditioner, only the manufacturer knows.... unless you can get a hold of the schematics.

As to longevity, its the MOV (metal oxide varistor) thats the issue. It degrades over time as surges damage the internal device structure through thermal stress. AFAIK, a MOV's useful life can be non-existent (ie won't help with next surge) and yet not be detected.

If anyone is intimately familiar with these devices, please yell out - I'm curious as to what those "health indicator" lights are on the surge protection power strips.

Edit:
Switch mode power supplies (eg most computer PSUs) have a pretty good tolerance to line voltage variations; line conditioning has limited impact. As mooo pointed out, brown outs can be a major issue, which is worse than just a transient undervoltage. Unfortunately, no line conditioner can mitigate against a "sustained" brown out, only a UPS can do that (energy gotta come from somewhere!)

Some analog AV equipment that relies on a stable voltage level - in this case line conditioning can become more important.

ces
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Re: Choosing surge protectors

Post by ces » Mon Mar 12, 2012 5:22 am

Elrast wrote:Switch mode power supplies (eg most computer PSUs) have a pretty good tolerance to line voltage variations; line conditioning has limited impact. As mooo pointed out, brown outs can be a major issue, which is worse than just a transient undervoltage. Unfortunately, no line conditioner can mitigate against a "sustained" brown out, only a UPS can do that (energy gotta come from somewhere!)
The specs on the Tripp Lite line conditioners certainly seem to indicate that they can adjust to brownout on a sustained basis. And I have seen one of mine do that (it has lights indicating the input voltage)

I have always assumed that it is not creating energy, but just converting one voltage into another, like a transformer does. The interesting thing is that the Tripp Lite warranty is a lifetime warranty. So they must think that (a) it won't wear out, or (b) the sales benefits resulting from the warranty exceed the cost of fullfilling the warranty.

Klusu
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Re: Choosing surge protectors

Post by Klusu » Mon Mar 12, 2012 1:02 pm

A MOV costs half a dollar. All the rest is marketing.
The best bet is to buy just a MOV.
Yes, your MOV may be dead after one big surge (or several not so big surges). Replacing after 3 years, whatewer, seems stupid. Just buy a bigger MOV (or connect 2 or more in parallel).The voltage at which the MOV kicks in should not be too close to your line voltage.
Brownouts (or some overvoltage) should not be a problem for today's computer PSUs.

Falkon
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Re: Choosing surge protectors

Post by Falkon » Mon Mar 12, 2012 1:12 pm

I use Panamax surge protectors/line conditioners. You could pick up something like the M8-EX for ~$70 and it should do everything you need and then some.

westom
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Re: Choosing surge protectors

Post by westom » Mon Mar 12, 2012 7:53 pm

Elrast wrote:Line conditioners have some smarts in them to adapt to changes in line voltage.
You are concerned about things that are trivial. And confusing them with others that may be a concern. Mostly because every concept must come with a perspective - the numbers. Any conclusion without numbers can be both true and false.

Line conditioners - electronics takes the cleanest or 'dirtiest' electricity. Converts 120 volts to well over 300 volts DC. Then converts that to the dirtiest electricity in the building - high voltage radio waves. Eventually converts all that to rock solid and cleanest DC.

Any conditioning done on a power cord is completely undone. And then done better inside electronics. Why do so many recommend conditioning? They don't know how a power supply works. Do not know those numbers such as high voltage and radio frequency power. Then recite subjective claims from advertising as if fact.

Claims with integrity include numbers such as those found in the specifications.

MOVs degrade. Then we temper that claim with numbers. One can put near zero protection inside a power strip or UPS. Then hype it into 100% protection using advertising (subjective claims). View manufacturer spec numbers. How do its hundreds of joules absorb transients that are hundreds of thousands of joules? Simple. By undersizing it, then its failure gets many to recommend that high profit product.

Many UPSes simply have enough (near zero) joules so that advertising can hype it as a protector. Since destructive surges occur maybe once every seven years, then many will claim it must work due to no damage for three years. Again, hearsay exposed by numbers.

Degrading is a problem when a protector is undersized. For example, a test defined by one MOV manufacturer:
> The change of Vb shall be measured after the impulse listed below is applied
> 10,000 times continuously with the interval of ten seconds at room temperature.

Can your expensive protectors withstand 10,000 surges and not degrade?

Discussions about line conditioning must also address many electrical anomalies. For example, it must discuss longitudinal and transverse currents. A longitudinal current could pass right through a UPS. The current on both sides of a battery means the battery never sees that transient.

Other anomalies include power factor, floating grounds, noise, voltage variations, harmonics, ground loops, short circuits, sags, etc. Most are already made irrelevant by existing solutions. No one device solves all. Many are made irrelevant by solutions already inside appliances.

For example, AC voltage can drop so low that incandescent bulbs dim to 50% intensity. That is ideal perfect voltage for all electronics. And may be harmful to motorized appliances such as a refrigerator.

Bottom line: separate useful replies from those invented by advertising and hearsay. Useful replies include numbers. No perspective (no numbers) - also called subjective claims - is why junk science is alive, well, and promotes so many scams.

ces
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Re: Choosing surge protectors

Post by ces » Mon Mar 12, 2012 8:35 pm

westom wrote:You are concerned about things that are trivial. And confusing them with others that may be a concern.
I am highly confident that what you have to say is highly important, but you said it so cryptically that it was hard for me to get a lesson out of it. I probably am not alone. May I ask you to expand on when you should buy a surge protector, a line conditioner or a UPS, what specific numbers you would look for when selecting from different surge protectors, line conditioners or UPSs, and what specific brands or models you might recommend. Thanks

westom
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Re: Choosing surge protectors

Post by westom » Mon Mar 12, 2012 9:32 pm

ces wrote: I am highly confident that what you have to say is highly important, but you said it so cryptically that it was hard for me to get a lesson out of it. ... May I ask you to expand on when you should buy a surge protector, a line conditioner or a UPS, what specific numbers you would look for when selecting from different surge protectors, line conditioners or UPSs, ...
You are basically asking for a solution to all anomalies. Which one do you want to solve? A few of the many different anomalies were listed. Nothing will solve all.

Also stated - any recommendations without numbers are best assumed useless.

When should you buy a line conditioner, surge protector or meteor shield? Please define the problem. No solution is possible without first defining the problem. Even brand names say little. Too subjective. Solutions are found in specification numbers; not in a name.

Most anomalies are already solved. For example, a best line conditioner is already inside appliances. Obviously demonstrated in that previous post. So why are you still asking about a line conditioner? Because the example apparently was something new? That means reread it at least three times.

If you understood that post in a first reading, then you already knew it. If something is new, then at least three rereads are necessary. It was not cryptic. Much was previously unknown. That post explained why line conditioners are rarely needed. Reread it a few times.

How many dBs of noise must a line conditioner quash? How large is your voltage sag? Nobody can provide a useful solution to a subjective problem. Must we solve a surge called lightning or one sourced by your finger (static electric discharge)? Each sentence is an example perspective - a problem defined by numbers. Which one is your anomaly?

But again, most anomalies are already solved despite hearsay that says otherwise ... subjectively.

ces
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Re: Choosing surge protectors

Post by ces » Mon Mar 12, 2012 10:22 pm

westom wrote:If you understood that post in a first reading,
Actually I don't... but you seem to be knowledgeable about a subject many of us are ignorant about. The key question is when, if at all, should someone consider buying surge protector, a line conditioner or a UPS? What are the most common anomalies?

I think basically, you may be overestimating the knowledge of a huge portion of readers of your posting.

If you don't want to bother sharing your knowledge that's fine. If you do, I think many of us would find it helpful. You might even want to start your own thread on it.

Elrast
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Re: Choosing surge protectors

Post by Elrast » Tue Mar 13, 2012 4:09 am

Klusu might have a point there. I'll grab just an Eaton POD for now.

Gonna look up some application notes for MOVs - then maybe its just a matter of getting a few digikey parts (and I can replace after storms).

westom
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Re: Choosing surge protectors

Post by westom » Tue Mar 13, 2012 8:32 pm

ces wrote: What are the most common anomalies?
A most common anomaly is probably the blackout. Despite popular myths, blackouts do not damage appliances. Due to industry standards that have existed long before computers existed. Blackouts are a threat to unsaved data. Purpose of a UPS is to provide time to save unsaved data. It outputs temporary and dirty power during a blackout to save data. It does virtually nothing for hardware protection.

Another less common anomaly is a brownout or sag. Sufficient voltage for any electronics appliance is voltage so low that incandescent lights may even dim to 50% intensity. Sufficient voltage for electronics might also be too low (harmful) to motorized appliances.

To protect motorized appliances, the utility disconnects power if voltage drops that low. An example of an anomaly solved elsewhere.

Another anomaly is noise. Sometimes a pop is heard in speakers. Noise that should be quashed by circuits existing inside electronics. However, if the noise is incoming on some other path (ie audio cables, antenna), then a solution must be implemented by appropriate filters, grounding, or other methods. Even better and much simpler is to solve a noise problem at the source.

Noise is an irritation. Not a reason for appliance damage. Many mistakenly assume a loud noise must be a violent hardware threat. Rarely if ever.

Harmonics can cause problems especially for motorized appliances. Excessive harmonics should never be incoming on AC mains. That solution is best solved by the utility.

Some have felt shocks between their TV and TV cable. That voltage difference should never exist due to single point grounding required to exist in all buildings. The TV cable, telephone, satellite dish, and AC electric all must share a common ground. Some will spend money on isolators or other gizmos when the solution is best accomplished by inspecting and correction defective grounds.

EMI/RFI/EMC can become a complex problem. However FCC regulations require all appliances to have appropriate filtering. Difficulty begins when first identifying the source of interference. Only then can appropriate measures be recommended to solve it.

Some far less common anomalies are indicated by dimming (or brightening) incandescent bulbs. No bulb should dim when any major appliance power cycles. This may be as simple as finding the loose wire in that branch circuit or receptacle. However, if that condition occurs on multiple circuits, then a potentially serious human safety problem exists (ie a floating neutral). Someone with sufficient knowledge should be consulted. There is no acceptable reason for lights to change intensity.

Tripping breakers are a common anomaly. Most anyone can understand a short circuit that trips the standard breaker. More difficult are more expensive (ie GFCI) breakers. This type breaker also trips due to leakage currents. All appliances leak currents. But many on the same breaker should never leak anywhere near enough current to trip that breaker. Again, a solution begins with the hard part. First identifying the leakage. For example, a wire in soil nibbled on by a critter might only cause tripping when the ground is most wet. Or multiple leaking appliances might leak just enough to intermittently trip a breaker. Rarely is the breaker itself defective. But finding the anomaly can be difficult without additional knowledge or maybe some simple tools.

High voltage can cause premature light bulb failure. For example, 120 volt mains at 127 volts can half a bulb's life expectancy. A voltage of 130 volts is quite safe and sufficient for any appliance - especially electronic appliances. Ideal voltages for all electronic appliances are both well below and well above what any utility is permitted to supply. Overvoltage can only be solved by the utility. The hard part is identifying that the anomaly exists.

Static electric discharges (ie less than 18,000 volts) can be a serious threat to electronics. Newest electronics are now required to withstand 2000 and 15,000 volts transients without damage. Notice spec numbers for the individual parts. A logic chip can be damaged by over 40 volts. But when that same chip becomes part of a larger system, then its abilities might increase to those 2000 or 15,000 volt numbers.

Better still is to not have static electric discharges. One most common solution is humidity. At least 20% or ideally a 40% relative humidity is the first line of protection for electronics.

These are some of the most common anomalies. Surges, for example, were not listed since a potentially destructive surge might occur typically once every seven years. A number that can vary significantly even in the same town. Many venues may not see a surge even in 20 years. But many will blame a surge rather then a far more common reason for appliance failure - manufacturing defects. How great is your risk? One way to obtain a number is to survey the neighborhood for at least ten years of history.

Klusu
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Re: Choosing surge protectors

Post by Klusu » Wed Mar 14, 2012 10:42 am

westom wrote:...Line conditioners - electronics takes the cleanest or 'dirtiest' electricity. Converts 120 volts to well over 300 volts DC. Then converts that to the dirtiest electricity in the building - high voltage radio waves. Eventually converts all that to rock solid and cleanest DC...
Written cryptically indeed. If somebody tries to read this as a clear text, after the third time they may think you don't know what the radio waves are.
The bottom line: almost nobody needs a surge protector, nor a line conditioner.

westom
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Re: Choosing surge protectors

Post by westom » Wed Mar 14, 2012 3:32 pm

Klusu wrote: If somebody tries to read this as a clear text, after the third time they may think you don't know what the radio waves are.
Some may foolishly think radio waves are only in the air. What is DSL? Radio waves on copper telephone lines. How do electronics create cleanest power? Convert cleanest AC mains power into radios waves on copper PC traces. Does not matter if a radio wave is in the air or on wires. It is still a radio wave. Electronics routinely create cleanest DC voltages by first making that incoming power very 'dirty' - a radio wave at tens or hundreds of kilohertz.

Any cleaning done by a line conditioner is first undone inside a power supply. Because a best line conditioner is inside each power supply. To convert those radio waves into pure and stable DC voltages.

A solution cannot be recommended until the anomaly is first defined. Which electric anomaly must be solved?

Klusu
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Re: Choosing surge protectors

Post by Klusu » Thu Mar 15, 2012 1:10 am

You really don't know what you are talking about. Radio waves are a "type of electromagnetic radiation", waves in wires are not radio waves. 100kHz equals to a wavelength of about 3km, how would you place that inside a PSU? Pure and stable 300V 100kHz power is not dirty. Power is dirty, if it contains surges, spikes, sags, any irregularities.
westom wrote:Any cleaning done by a line conditioner is first undone inside a power supply.
Nothing is undone. A conditioner makes the job easier for the PSU, the end result must be a little better.
Last edited by Klusu on Sat Nov 24, 2018 3:45 am, edited 1 time in total.

westom
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Re: Choosing surge protectors

Post by westom » Thu Mar 15, 2012 8:37 am

Klusu wrote: Power is dirty, if it contains surges, spikes, sags, any irregularities.
And again. 'Dirty' power is filtered. Then converted to an even higher voltage DC. Then converted to very spiky, high voltage radio waves. Then more filtering. Converted to a high current. And eventually converted to a low voltage, rock stable, DC voltage. Multiple conversions and filtering routinely done inside electronic appliances make surges, spikes, sags, and other irregularities irrelevant. Anything a line conditioner might do is routinely done better inside electronic appliances.

If you don't like the word radio wave, then propose a better one. Contribute to the discussion rather than just posting empty denials.

Any conditioner that eliminated spikes; those spikes are made even worse inside a supply before creating a rock sold DC voltage from those radio wave spikes. A sag is simply converted to a much higher DC voltage to eventually result in a much lower and rock solid DC voltage - as you already noted.

Those various anomalies - 'dirty' electricity - are already made irrelevant inside electronic appliances. Listed were common anomalies and how they are already solved.

As you noted, MOVs are cheap. More like five or ten cents rather than 50 cents. Are mostly hyped by marketing when inside power strips. But can be part of a major solution when properly implemented. Which means MOVs must not fail. Failed MOVs means compromised protection and a possible house fire. Experimenters should learn why MOVs best are implemented with a thermal fuse.

The OP asked about a power strip which may be $4 with some ten cent protector parts. That sells for $25 or $100. Profit centers rather than surge protectors. How much was that Panamax or Isobar? Voltage adjuster (for some reason mislabeled as a line conditioner) does not use MOVs and was irrelevant to the OP's question about surge protectors.

Surge is an anomaly (ie once every seven years) made irrelevant by first defining the problem. Most important is where MOVs are implemented and what gets connected.

Klusu
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Re: Choosing surge protectors

Post by Klusu » Sat Nov 24, 2018 3:44 am

DC is converted to AC. Not to radio waves.

Let's take a rectifier, followed by a capacitor. An input spike would appear on the capacitor. Would appear on the AC. Perhaps would appear on the "rock stable" DC output.
AC is not dirty. AC with a 100V spike on top of it is dirty. Might kill the switcher transistor. PSUs die. Who knows why. How many are killed by spikes.

westom
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Re: Choosing surge protectors

Post by westom » Sat Nov 24, 2018 12:25 pm

Klusu wrote:DC is converted to AC. Not to radio waves.
DC is converted to AC - at multiple radio frequencies. Multiple frequencies that create spikes. And that exceed 300 volts.

'Dirty' is a vague expression for layman whose eyes glaze over with every number. That created AC is spikes that occur at radio frequencies. That are far 'dirtier' than anything found on AC mains. Due to superior filters, galvanic isolation, and regulation, well over 300 volt spikes result in rock stable, low DC voltages

300 volt volt radio frequency spikes are nothing more than a sum of AC waves at many frequencies. All are converted to rock stable DC that has no spikes and must not vary by even 0.2 volts. What part is confusing?

Klusu
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Re: Choosing surge protectors

Post by Klusu » Sat Nov 24, 2018 2:36 pm

So no more radio waves. Good.
PFC circuit converts the mains voltage to some 380V DC. Typical half-bridge converter converts this voltage to plus minus 190V pulses. You call them spikes? You call this dirty? I don't. This is intentional.
westom wrote:Any conditioning done on a power cord is completely undone.
Are you saying MOVs on the power cord are completely superfluous?

westom
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Re: Choosing surge protectors

Post by westom » Sat Nov 24, 2018 4:20 pm

Klusu wrote:So no more radio waves. Good.
What you have called AC are radio frequency waves or spikes. No difference. It is not a DC current. Is it a wave, spike, or 'dirty' AC waveform at radio frequencies. Nobody was saying anything about active PFC. Where did that come from?

Typical power supply is powered from any AC voltage from 85 to 265 volts. (Some do it automatically; some require a switch). Those create rock stable, low DC voltages from well over 300 volt radio frequency waves - even with only passive PFC.

MOVs on a power cord are obviously ineffective once one learns the technology and numbers. Better manufacturers stop doing that long ago for a long list of reasons. For example, how many joules does that MOV claim to 'absorb'? A hundreds joules surge, routinely converted by a power supply into those rock stable, low DC voltages, can also destroy that tiny joule MOV. Any protector that fails on a non-destructive surge is ineffective. Also called a near zero joule protector.

Effective MOVs are only connecting devices to what does protection. MOV on a power cord must either 'block' or 'absorb' a surge. It clearly cannot.

Third, an MOV too close to an appliance and too far from earth ground simply gives that surge even more paths to find earth ground destructively through adjacent appliances. Plenty more reasons also demonstrate why a tiny joule MOV does nothing useful.

A power supply is so robust as demonstrated by numbers. Adjacent MOVs only exist when myths are promoted by subjective reasoning such as hearsay, wild speculation, and advertising. Informed consumers know any effective solution always answers this question (again with numbers). Where do hundreds of thousands of joules harmlessly dissipate?

Anything that MOV might do is already done better by existing and standard circuits that even create well over 300 volt waves and then convert them into rock stable DC voltages that do not vary by even 0.2 volts. Informed consumers know that the existing, internal, robust protection (without using protectors) can be overwhelmed by a rare transient if a 'whole house' solution is not properly earthed.

Klusu
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Re: Choosing surge protectors

Post by Klusu » Mon Nov 26, 2018 7:27 am

Waves and spikes are not synonyms.
"That created AC" is not spikes. More like a square wave. The pulses have certain duration.
westom wrote:Converts 120 volts to well over 300 volts DC.
Who converts, if not active PFC?

westom
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Re: Choosing surge protectors

Post by westom » Mon Nov 26, 2018 2:41 pm

Klusu wrote:Who converts, if not active PFC?
Waves. spikes, and AC waveforms ('dirty' or not) are all a sum of sine waves. Please relearn Fourier Series as taught in high school math. All are subjective expressions for a same thing. If you disagree, then I am viewing numbers and mathematics that says otherwise.

Also apparent is a lack of knowledge; how power supplies work. A long discussion to teach this must not be here. You are expected to learn, for example, from the so many applianction notes attached to so many different power supply controller datasheets.

This executive summary from those app notes: AC electricity is first filtered (with or without active or passive PFC). Then converted to DC voltages. And filtered again. Then converted to well over 300 volt radio frequency spikes. Any 'dirty' AC or 'conditioned' AC is now completely undone.

Then radio frequency spikes are converted by superior filters, galvanic isolation, and regulators into rock stable, low voltage DC completely with more filters. Robust protection is already inside each power supply.

That robust protection is superior to what any plug-in protectors claim to accomplish - with numbers. That is robust protection that may be overwhelmed by an anomaly (ie for microseconds once every seven years). That anomaly is routinely averted by properly earthing a 'whole house' solution - a least expensive solution.

Series mode filters (ie Surgex), power conditioners, plug-in protectors ($10 one from Walmart or the electrically similar Isobar), and ferroresonant transformers do not claim effective protection. Otherwise I am reading specification number that claim such protection. Where are those numbers? Will anyone finally post some?

For example, a Surgex will absorb maybe 600 (near zero) joules and then saturate; stop providing any more protection. Effective protection always answers this question. Where do hundreds of thousands of joules harmlessly dissipate? That answer was well understood and routinely implemented even over 100 years ago - when people were educated by science; not by hearsay and advertising.

It was always this simple. A protector is only as effective as its earth ground. And that too was defined by numbers. None of those plug-in solutions have the required earth ground. None claim effective protection as demonstrated by so many posts devoid of any specification numbers.

Klusu
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Re: Choosing surge protectors

Post by Klusu » Tue Nov 27, 2018 1:26 am

westom wrote:apparent is a lack of knowledge
Indeed.
westom wrote:AC electricity is first filtered (with or without active or passive PFC). Then converted to DC voltages.
Could you
show one circuit diagram supporting this?
Btw, ferroresonant transformers may be the best protectors (but they have their drawbacks).

Olle P
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Re: Choosing surge protectors

Post by Olle P » Tue Nov 27, 2018 5:20 am

Just wanted to chip in that the one time I've had a surge problem it came through the network cable. (Using cable-TV for Internet as well.)
The WAN-side of my router died quietly as a result.

westom
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Re: Choosing surge protectors

Post by westom » Tue Nov 27, 2018 6:10 am

Olle P wrote:I've had a surge problem it came through the network cable. (Using cable-TV for Internet as well.) The WAN-side of my router died quietly as a result.
A surge is electricity. It must have an incoming and a completely different outgoing path. If incoming was on a TV cable, then what was the outgoing path?

That surge is typically a connection from a cloud (maybe three miles up) to earthborne charges (maybe four miles through earth). Surge damage is when that current is inside a house. Incoming on TV cable. What was the outgoing path to earth?

TV cable and telephone already have best protection installed for free. Your conclusion must be preceded by first collecting facts. Why was a hardwire from that TV cable to earth ground not installed? (Wall receptacle safety ground is not earth ground.) If that required surge protection exists, then TV cable is not the incoming path.

So what is a most common incoming path? A lightning strike to highest wires (AC electric) many blocks down the street is a direct strike incoming to all household appliances. Are all appliances damaged? Of course not. Again, not all appliances have a best outgoing path to earth.

That surge was all but invited inside by a homeowner who failed to properly earth 'whole house' protection. Surge was inside hunting for earth ground destructively via appliances. It found a best connect to earth via a modem and its 'always required' surge protection on that TV cable.

Now we have science - a hypothesis. Incoming on AC mains. Outgoing tp earthborne charges (ie four miles distant) via a properly earthed TV cable. Damage is often on the outgoing path. Consumers who make conclusions only from speculation *assume* damage is only on an incoming path. Too many make conclusions by only *assuming*.

Appreciate how much must be learned and done long before making any conclusion. You had modem damage because a surge was all but invited inside to go hunting for earth ground. Since the modem was a best path to earth, then a surge did not use a dishwasher for a destructive path. To learn from a mistake and to avert all future surges, every wire inside every incoming cable must make a low impedance (ie less than 1 foot) connection to single point earth ground.

Cable TV should already have a hardwire to that only earth ground. Telephone cannot connect direct to earth. So the telco installs a protector *for free*. That protector (like all effective protectors) does not do protection. It only connects a surge low impedance (ie less than 10 feet) to a same earthing electrode. Protector only does what a cable TV's hardwire does better - without any protector.

AC electric are only incoming wires not required to have surge protection. If a homeowner does not properly earth a 'whole house' protector, then surge damage is directly traceable to that homeowner's mistake. If a 'whole house' protector connects low impedance (ie hardwire has no sharp bends or slices) to the same earth ground, then a lightning strike far down a street does not hunt for earth ground destructively via any appliance (furnace, GFCIs, clocks, refrigerator, smoke detectors).

As with anything in reality, a soundbyte cannot define it. However a fundamental point can be summarized. Effective protection always answers this question. Where do hundreds of thousands of joules harmlessly dissipate. If inside, then no effective protection exists. Any protector is only as effective as the (low impedance) connection to and quality of earth ground.

Critical details such as a protector's specification numbers and single point earth ground require more discussion. This only summarized what every homeowner is responsible for knowing. Since surge damage (even from direct lightning strike) is traceable to a human mistake.

westom
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Re: Choosing surge protectors

Post by westom » Tue Nov 27, 2018 6:32 am

Klusu wrote:Btw, ferroresonant transformers may be the best protectors (but they have their drawbacks).
Again a mistake of making a conclusion only from hearsay. Put some numbers to your belief? What is its galvanic isolation voltage? A fact that must be learned long before making any conclusion.

How does a millimeters separation between a primary and secondary somehow 'block' what three miles of sky cannot? More damning numbers.

Go to manufacturer application notes for any power supply controller. TI.com or st.com have plenty of examples such as for the TL494. Or do a search for ATX power supplies. There would probably be 10,000 examples. A simpler one that looks similar to what was in the original IBM PC: ie http://danyk.cz/s_atx01a.png

Klusu
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Re: Choosing surge protectors

Post by Klusu » Tue Nov 27, 2018 7:23 am

Millimeters separation isolates about 1000V. Can your PSU survive 1000V? I don't think so.
Could you show one circuit diagramm supporting "AC electricity is first filtered (with or without active or passive PFC). Then converted to DC voltages." ? In this order, with active or passive PFC.

westom
Posts: 45
Joined: Sun Feb 14, 2010 9:20 pm
Location: USA

Re: Choosing surge protectors

Post by westom » Tue Nov 27, 2018 1:06 pm

Klusu wrote:Millimeters separation isolates about 1000V. Can your PSU survive 1000V?
First, yes it must. Back when the IBM PC first appeared, international design standards required 120 volt electronics to withstand up to 600 volts without damage.

Or view this datasheet for a signal interface IC. What must it withstand without damage?
https://datasheets.maximintegrated.com/ ... AX491E.pdf

15,000 volts. Tiny voltage interface chips today are even more robust - routinely withstanding up to 2000 or 15,000 volts without damage.

But again, the point. One is suppose to learn from science, datasheets, informed sources, and numbers long before making any conclusion.

Second, already posted is an example from over 30 years ago of "... one circuit diagramm support... "AC electricity is first filtered (with or without active or passive PFC). Then converted to DC voltages."

AC voltage is clearly filtered. Then converted to DC. Then filtered again, Then converted to well over 300 volt radio frequency spikes. All that means a power supply makes most AC power anomalies irrelevant. And means that IBM PC can even withstand surges that may destroy plug-in protectors.

At least one Seasonic power supply said, quite bluntly, that it can withstand up to 1800 volt transients.

Third, one learns some basic electrical concepts always taught to first year engineers or physic majors. A surge is a current source. That means voltage only increases when something foolishly tries to block it - such as a ferroresonant transformer. The voltage from a potentially destructive surge will easily blow across that 1000 volt galvanic isolation.

Anything inside, that foolishly tries to 'block' or 'absorb' a potentially destructive surge , is best suspect as a scam. Why is a 'whole house' solution so effective? It simply connects a surge to what it is hunting for. Then a 20,000 amps surge (ie lightning) creates a near zero voltage. Nothing inside is damaged. And hundreds of thousands of joules harmlessly dissipate outside.

Nothing new. This is how protection was routinely done in telco COs that could suffer about 100 surges with every thunderstorm - and no damage - long before any of us existed. Any informed homeowner implements same for about $1 per protected appliance. A fundamental concept, originally demonstrated by Franklin over 250 years ago, has not changed. A protector is only as effective as its earth ground. None of those magic boxes even claim such protection - let alone provide it.

And then this problem with protectors (such as that Belkin) that most recommend by ignoring well proven science: "House fire caused by faulty surge protector not on recall list, Kingwood chief says" at:
http://www.nj.com/hunterdon-county-demo ... fault.html

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