Surge protection do we really need it?

[1nf3rn0x]

I'm pretty sure my psu's have safety things like OPP/OCP/OVP/OTP. So i think i'm safe.

 

[Swamp Monster]

A gas tube simply gives a surge on the hot wire access destructively through that appliance via its neutral wire. That surge will enter on a utility wire. And obtain earth via a best path. Hot to neutral still means a surge inside the building must blow through something nearby to get to earth. A GDT hot to neutral only gives a surge more destructive paths.

I totally forgot about power transformer grounding! You too? and that makes me wrong about some things I wrote, but that makes you wrong about some things too.
Surge power really dissipates not in those elements, but in earth

No, not thru appliance, because neutral wire is grounded via power transformer/substation(don't ask me how exactly, I don't study energetics).
Hot to neutral means a surge inside the building will blow through GDT to get to earth via neutral wire thru power transformer.
So A GDT hot to neutral gives a surge options to dissipate somwhere else than precious equipment.

Keep in mind that I am not talking about most effective protection, but protection/schematic which I am talking about is also effective.
Again, those elements - be it MOV or GDT- when connected between hot and neutral are not useless.

 

[Swamp Monster]

I'm pretty sure my psu's have safety things like OPP/OCP/OVP/OTP. So i think i'm safe.

Your PSU's safety marks(OPP/OCP/OVP/OTP) are relevant only to your PSU's output. It means yout PSU should not mess up your motherboard if it fails due to overload.

 

[westom]

I totally forgot about power transformer grounding! You too? and that makes me wrong about some things I wrote, but that makes you wrong about some things too.

I did not forget about power transformers. You are confusing a primary protection system with the secondary protection system. We have been discussing the secondary system. You are again jumping to conclusions (accusations) rather than asking.

By now, you should have known that each protection layer is defined only by the item that does protection. Everything inside a building is only part of a secondary protection. Defined by how each protector connects to protection - single point earth ground. Those components with good earthing do protection. Those without are wasted money or sometimes can make damage easier.

A GDT from hot to neutral does not earth that GDT when too far from earth ground and too close to electronics. Wire impedance is a serious problem when using plug-in protectors (therefore GDT not connected to earth). And wire impedance increases protection when that same wire creates distance between the protector and electronics.

For example, telcos want protectors to be in a vault where all wires enter the building. And where the connection to earth is low impedance. As short as possible - every one foot shorter is important. Also protectors are located up to 50 meters distant from electronics. Higher impedance between protector and electronics means better protection.

Now, for the primary protection system. Inspecting this protection device is critical:
http://www.tvtower.com/fpl.html

First because one wire gets earthed. But moreso is a problem defined by Colin Bayliss in "Transmission & Distribution Electrical Engineering":
> Although lightning strikes have impressive voltage and current values (typically hundreds to
> thousands of kV and 10-100 kA) the energy content of the discharge is relatively low and most
> of the damage to power plant is caused by 'power follow-through current'. The lightning
> simply provides a suitable ionized discharge path.

What happens when lightning creates a plasma path from primary to secondary? 13,000 volts may now be connected directly to household incoming wires. That type of surges result in, for example, sparks flying out of wall receptacles. Just one example of what the transformer earth ground must avert.

Meanwhile, a 1970 IEEE paper put numbers to another typically destructive surge. A worst lightning strike to wires down the street was 40,000 amps via the utility pole earth ground. The primary protection system. And another 20,000 amps incoming to each house. A secondary protection system. Each protection layer defined only by what does protection - each earth ground.

A GDT hot to neutral is ineffective. A 6000 volts surge is on the appliance while near zero volts is across that GDT. GDT was not earthed. So the GDT is defined by the NIST: “The best surge protection in the world can be useless if grounding is not done properly.”

That GDT has no earthing as has been explains so many times for so many reasons. But again, you cannot ignore critically important phrases such as "less than 10 feet", wire impedance, single point earth ground, "protector and protection are two different components", and low impedance. Even sharp wire bends and splices mean a wall receptacle safety ground is not earthed.

 

[westom]

I'm pretty sure my psu's have safety things like OPP/OCP/OVP/OTP. So i think i'm safe.

Those functions are part of a protection system inside every power supply. Just a few examples of why the best protection at electronics is already inside that supply. But that protection system can be compromised by a power strip protector too close to electronics and too far from earth ground. We saw this often. In one example, power strip protectors earthed that surge through a network of powered off computers.

A power strip protector simply connects, for example, a black hot wire surge to the green safety ground wire. Now that surge bypasses a supply. Connects directly to the motherboard.

This paragraph is very important because most never grasp this. An incoming surge (not earthed by a 'whole house' protectors) strikes every and all appliances. Why are all appliances not damaged? It is called electricity. If an outgoing path also does not exist, then no surge current exists. Always discuss the outgoing path.

A protector connected that surge directly to the motherboard. What is the outgoing path to earth? Through a motherboard, through the modem, out via the phone line, and to earth via an 'always install by the telco' protector. This failure caused a famous “No Dialtone Detected” message.

OPP/OCP/OVP/OTP did nothing to protect. For example a 6 volt OVP would not even see a maybe 1000+ volt surge destructively through motherboard and modem.

Same is why series mode filters (ie Brickwall) are also bypassed.

All appliances contain serious protection. But your concern is surges that can overwhelm or bypass protection. Once a destructive surge is inside, then nothing can avert a hunt for earth. Grasp that sentence like your life depended on it. Anyone hyping interior magic boxes is better classified as a con artist. Either energy dissipates harmlessly outside the building. Or that energy will select appliance to destructively obtain earth. Demonstrated is one example of why plug-in protectors (or a GDT hot to neutral) can even make damage easier.

There exist so many ways that damage can happen. One simple solution eliminates numerous reasons for damage. If energy is inside, then nothing will stop a destructive hunt. Numerous reasons for damage disappear when surge energy finds earth without entering a building. Therefore informed homeowners spend most money on what means no energy inside the house. Single point earth ground is the art of protection. AND the only protection component that every protection system must always have. That (and not inside some magic box) is where superior protection is obtained.

OPP/OCP, etc are why appliances are so robust. But your concern are many ways that appliance internal protection can be compromised by a transient that occurs maybe once every seven years. An event sometimes made even more destructive by protectors without the ‘always required’ short connection to earth.

Protection is always about where energy dissipates. Therefore a protector is only as effective as its earth ground.

 

[Munki]

I use a cyberpower from the walmart

 

[m4gicfour]

I get what you're saying Westom. I'm no engineer, but I get it.

The average surge protector might work for very low energy (joules) surges (or more properly - spike?) Still, it only works by attempting to divert energy away from the "protected" equiptment. (from hot to neutral, or to ground - either way, it's expecting the branch wiring to be able to take that energy either back through the power transformer or to the panel ground)

When dealing with a true surge (lightning, utility surge), a power strip style protector is simply non-functional. Energy levels that are high enough to coarse through the air as a lightning bolt can easily jump between wires, making a return path through branch wiring irrelevant. (massive energy is coming FROM the branch wiring, enough to nullify the wiring's insulation. There may be no return path, all wires are likely energized. Hot, neutral, and ground are carrying the lightning surge to anything that is connected. )

If a protector tries to (or does as a consequence of failure) shunt that energy to the saftey ground (green or bare wire, assuming only the hot wire is carrying the surge) it can actually make things worse since every device connected to the circuit is connected to that ground, and the surge doesn't have to travel through components to get there. Whichever device attached to that ground wire has the lowest impedance to true ground from that point becomes the grounding path, and thats where the surge goes. For example the surge might go from the building wiring through a "surge protector", to the ground wire, to any device attached to the ground wire, then the lightening jumps inside that device to say, a phone line, coax, or networking cable attached to that same device and from there to whatever's on the other end of that wiring - if no easier (lower impedance) path to true ground exists. Same should be true of attempting to shunt to neutral.

What is needed is a direct, low-impedance path to ground, and it needs to be as far as possible before anything you want to protect. The only effective way is to place a protection device (a device which shunts excess energy to ground - not any building wiring, but literally: the ground - the earth) at the electrical panel which supplies the entire building.

This makes a path of least resistance for the surge very close to where the surge is coming from, and relies on no branch wiring to handle the surge. Energy is directly and safely shunted to the earth at the source.

long story short - for lightning-class energy levels, it's easier for the energy to go from the wiring through the "surge protector" (here meaning power-strip) through any and all circuitry (and potentially through insulators, air gaps, etc) to ground in whatever fashion is easiest than to travel back through the building's wiring. By the time the energy reaches the power strip, it's too late - unless that power strip has a massive metal stake several feet into the earth as its return path rather than trying to bridge to building wiring. Even if it did, all other devices in the house would be at risk - again, the ground path must be made where the power enters the building to protect anything properly.

 

[Swamp Monster]

long story short

You deserve thanks for telling long story short. Nice summary

 

[Swamp Monster]

I did not forget about power transformers. You are confusing a primary protection system with the secondary protection system. We have been discussing the secondary system. You are again jumping to conclusions (accusations) rather than asking.

You deserve thanks for your effort! I even learned something.
As I already told, this isn't really my field. I am atleast 20 years younger than you, so it's allowed for me to jump to conclusions.
(GDT or MOV in cheap surge protector)- is grounded also thru power transformer, so you have both - primary and secondary grounding in your house - so we are discussing both.

A GDT from hot to neutral does not earth that GDT when too far from earth ground and too close to electronics. Wire impedance is a serious problem when using plug-in protectors (therefore GDT not connected to earth). And wire impedance increases protection when that same wire creates distance between the protector and electronics.

I know that transformer's grounding too have some impedance, but it is solid, well built anyway. Thanks for link btw.

What happens when lightning creates a plasma path from primary to secondary? 13,000 volts may now be connected directly to household incoming wires. That type of surges result in, for example, sparks flying out of wall receptacles. Just one example of what the transformer earth ground must avert.

Don't frighten me with sparks flying out of wall receptacles, I am not that young. I don't care - It is only a side effect, and good example too

Meanwhile, a 1970 IEEE paper put numbers to another typically destructive surge. A worst lightning strike to wires down the street was 40,000 amps via the utility pole earth ground. The primary protection system. And another 20,000 amps incoming to each house. A secondary protection system. Each protection layer defined only by what does protection - each earth ground.

In case lightning strikes thru earth, then every protection is ineffective (1970 IEEE paper is a Worst case scenario). As well I can say: If lightning strikes near your house, then your super grounding will not work either.
More so - you probably know that proper grounding costs thousands of dollars?. I live in pre-2nd world war house with no grounding, (I believe I am not the only one) so primary protection triggered thru cheap protector is only option for me.

A GDT hot to neutral is ineffective. A 6000 volts surge is on the appliance while near zero volts is across that GDT. GDT was not earthed. That GDT has no earthing as has been explains so many times for so many reasons.”

Why was not earthed? It has earthing if not cut, like in your link.
U=I*R, as you say - few volts on GDT. according to schematic (parallel) few volts also on appliance. Are you discarding laws of electronics?
Should I post the same picture with numbers, so you understand?

But again, you cannot ignore critically important phrases such as "less than 10 feet", wire impedance, single point earth ground, "protector and protection are two different components", and low impedance. Even sharp wire bends and splices mean a wall receptacle safety ground is not earthed.

And again I am not ignoring this. I am saying that it may not work if hit by massive lightning(100 KV/1000KA) because of impedance, but it can work when smaller surge(6KV/100A) is present. And I understand, your inflexible opinion is like that, because you work in company that does this stuff. All just have to be perfect, right?

 

[westom]

(GDT or MOV in cheap surge protector)- is grounded also thru power transformer, so you have both - primary and secondary grounding in your house - so we are discussing both.

Again, an expression that should have your attention every time: "less than ten feet". Any protector earthed by a utility power transformer is myth. Too far from earth ground. And the protector will, instead, use a nearby appliance to obtain earth - destructively. An IEEE figure demonstrates this. The protector (ie GDT hot to neutral protector) earthed that surge 8000 volts through a nearby TV.

Another example demonstrates what you must know before making any conclusions. Connect a 200 watt transmitter to a half wave antenna. Touch one part of that antenna wire. Feel zero volts. Touch another part and get a maybe 100 volt shock. How can two parts of the same wire be at two completely different voltages? Because you keep thinking in terms of DC and resistance. Are not thinking in terms of AC and impedance.

Why do you mention fear? Emotion has no place here. Sparks flying out of receptacles happens how often? Virtually never. But it has also happened to some. What so many never understand: those sparks are not from lightning. Those sparks are from a higher energy source - AC utility. An event because galvanic isolation inside a transformer is compromised by lightning (by plasma). In that case, ground is about maintaining galvanic isolation so that sparks do not fly out of your receptacle. But another reason why inspection (see the tvtower.com picture) should have every reader's attention (like another critical phrase - single point earth ground).

Never entertain emotions such as fear. Always understand why, for example, some have seen sparks flying out of receptacles. And why inspection (see that tvtower.com picture) is what everyone reading this should do.

Direct lightning strike without damage is routine (ie 23 direct strikes annually to electronics atop the Empire State Building without damage). Your telco's computer connects to overhead wires all over town - without damage. Earthing is why. For some, equivalent is only two earth ground rods (as required by code). For others, that can mean massive earthing (ie Ufer grounds). But this you know from every telephone CO in every town. Protection is installed so that direct lighting strikes cause no damage. Provided were numbers that show why the informed knew that even before 1900. Provided were numbers for the cost: $1 per protected appliance.

Accusation that I am inflexible is an insult to science. I did this stuff. You did not even learn basic concepts (such as zero volts and 100 volts on the same wire). Inflexible is when one makes conclusions without first learning facts and numbers. Another example that everyone should have learned from history. Inflexible were so many Americans with contempt for the American soldier. They knew Saddam had WMDs when facts and numbers said otherwise. Not having learned from that mistake defines "inflexible". Everyone reading this should have learned that simple lesson. And yet the concept is widely ignored.

You don't have knowledge and are still posting conclusions. Ie. protector earthed by the utility's transformer. Not possible. Even the executive summary says why: "less than 10 feet".

To get beyond "knowledge from an executive summary" means first learning things such as impedance. Or why an antenna wire can be 100 volts in one spot. And zero volts elsewhere. Why a ground wire inside metallic conduit compromises an earth connection. Or the significance of "equipotential and conductivity".

Spend less money for 100kA protection. Then a trivial 100 A surge is irrelevant. So that a 100kA surge does not damage, spend $1 per protected appliance. Those plug-in protectors for tens or 100 times more money do not even protect from a 100A surge. If you disagree, then you posted manufacturer spec numbers. No spec number posted because it does not do that protection. And cost tens or 100 times more money. Hard facts that explain why Monster Cable also markets these products.

Polyphaser, an industry benchmark, makes a protector without any connection to earth. That Polyphaser mounts ON earth ground. Zero feet to earth ground means even better protection. Distance to earth is critical. But not understood if discussing resistance. If making conclusions without first learning the basics. Making conclusions using only 'executive knowledge'.

Again, wire impedance is why a protector needs a single digit foot connection to earth. Why a wall receptacle has no earth ground; is only a safety ground. And why a power transformer does not provide household earthing.

How much should you learn? One house did not have any earth ground. Lights worked fine. So the homeowner remains uninformed. A failure in a street transformer meant electricity flowed through the gas meter. Fortunately no one was home when it exploded. Damage because the homeowner had no idea why earth ground is critical. And why only inspection can identify the failure. Again, nothing here is about fear. It is 100% about what every homeowner is responsible for inspecting and maintaining. Fear any homeowner who does not learn his responsibilities.

 

[westom]

I get what you're saying Westom. I'm no engineer, but I get it.

Your summary demonstrates a grasp of the basic concepts.

To remember these concepts, learn some soundbytes. First, protection is always about where energy dissipates. Either energy dissipates harmlessly outside the building. Or energy is inside hunting for earth via some appliance.

Second, surges are selective. Everything suffers the same incoming surge. But only one or some appliances also suffer an outgoing current to earth; are damaged. Both an incoming and outgoing path must exist.

Third, no protector does protection. Protection means energy connected to the only thing that does protection: single point earth ground.

Fourth, ineffective protectors fail - which means no protection.

Fifth, plug-in protectors are protection from a type of surge that typically does no damage. Protection already inside appliances means those transients are only noise.

 

[Swamp Monster]

Accusation that I am inflexible is an insult to science. I did this stuff.

I didn't want to insult you, blame google translate. it was meant that you don't agree not even with one thing I say. Does unshakable opinion sounds better?
About sparks-I was in good mood, I think You are taking this too serious.
Good discussion and good points anyway, thumbs up.

You don't have knowledge and are still posting conclusions. Ie. protector earthed by the utility's transformer. Not possible.

I have knowledge and I am sharing with it. i am in good mood, so i will take no offense this time.

Maybe PM you, to not confuse others? If I have some questions...

 

[westom]

I have knowledge and I am sharing with it. i am in good mood, so i will take no offense this time..

Expanding on questions asked by Swamp Monster is, for example, a power transformer located inside the building.

Building code says the secondary side of any power transformer must be grounded. Grounded for human safety. For example, that ground can be one side of the transformer. Or could be a tap on its winding. But that is for human safety. Any floating secondary seriously increases threat to human life. For example, a 440 volt to 6 volt transformer secondary could put the 6 volt secondary at 440 volts if that secondary winding was not safety grounded. Bad (missing) ground is called a "floating ground".

In this case, its safety ground is also the earth ground. Often a transformer secondary is firmly bonded to a steel girder. And because it is a separate ground, minor voltage variations exist. If all wiring is not carefully installed, then ground loops may occur because "grounding tends to shift it's level a little".

Grounding for human safety is insufficient for transistor safety. What is a minor voltage shift to 60 Hz power can also be major voltage shifts during a surge.

For transistor safety, every wire from that transformer secondary must be earthed. Every secondary wire cannot be earthed directly. For human safety, only one wire is safety grounded. For transistor safety, all other wires are earthed via a protector. That is what a protector does. As Dr Schneider says:
> Conceptually, lightning protection devices are switches to ground.

No protector does protection. A protector is a switch. Each protector connects one wire from that transformer to earth during a surge. If any one wire is not earthed, then protection is compromised.

And finally, if that power transformer is inside a building, then we have another earth ground. Effective protection requires single point ground. So each protection 'layer' must be carefully designed so that a transformer secondary ground is also another protection layer. That means communication wires and even heat ducts enter a new 'layer' integrated into that new protection system.


Second, once it was legal to connect an appliance safety ground to its neutral wire. Today that connection is a threat to human life. A safety ground (bare copper) wire connects to a neutral (white) wire inside the breaker box. But both wires are electrically different at the receptacle. Every wire is electrically different at both ends. Which is why an appliance neutral wire must always remain disconnected from the safety ground wire.

Wire is electrically different at both ends. Even a greater difference when discussing surges. Whereas electricians once considered neutral and safety ground wires equal at both ends. Today, those wires can only share a common connection inside the breaker box.


Third, some have three wire appliances but only two wire receptacles. Code provides an option. Two wire receptacle can be replaced with a GFCI. And a label that reads "No Equipment Ground" must be pasted on any receptacle powered by that GFCI. Then a three wire appliance can be used safely.

Once electricians simply connected a neutral (white) wire and safety ground (green) wire together. Today, that is considered a major threat to human life. A taboo.

This post is about human safety; meeting code. Surge protection is about wiring that also exceeds code (human safety) requirements.

Because wire is always electrically different at both ends, all safety ground and neutral wires must be electrically separate. Except where both wires meet inside one breaker box. This breaker box connects AC utility wires and earth ground to all safety ground and neutral wires.

 

[jpierce55]

I have seen computers die from not having surge protectors. They do really work. Have you considered that surges in your house can be caused by other things besides a power surge from the electric company? Another appliance going bad, switches going bad, outlets going bad all can damage your pc and a surge protector would help prevent it. You can get a cheap surge protector for practically nothing! $10 to protect $1000 of equipment is about the cheapest insurance out there.

No they won't protect against a direct lightening strike.

 

[m4gicfour]

To remember these concepts, learn some soundbytes. First, protection is always about where energy dissipates. Either energy dissipates harmlessly outside the building. Or energy is inside hunting for earth via some appliance.

Yup. Same reason linesmen can fly in helicopters up to and work on high-tension lines operating at 100s of thousands of volts safely so long as no ground path between the helicopter and anything else exists. So long as that is the case, the high tension wire is still the easiest path for the electricity to flow, and the linesmen are safe. Voltage is merely electrical pressure. Flow (current) is what is damaging. If sufficient voltage exists to create flow through anywhere you don't want it, and there's no failsafe which has a low-impedence shunt to ground then you're in trouble.

Second, surges are selective. Everything suffers the same incoming surge. But only one or some appliances also suffer an outgoing current to earth; are damaged. Both an incoming and outgoing path must exist.

Electricity flows along the easiest path. The same powerful voltage can be present nearly everywhere during a lightning surge. Only the device(s) which ends up being the grounding path is damaged, as it's the only device(s) that experiences the damaging large (1000s of A) current. What a TRUE protection device does is make the easiest path a non-destructive one (straight to earth rather than through wiring, equipment, then earth)

Third, no protector does protection. Protection means energy connected to the only thing that does protection: single point earth ground.

Fourth, ineffective protectors fail - which means no protection.

Fifth, plug-in protectors are protection from a type of surge that typically does no damage. Protection already inside appliances means those transients are only noise.

Plug-in surge protectors cannot disspate energy anywhere but back through the building wiring. In high-energy surges, this is not sufficient. Further, they wear out with everyday use. Low-energy transients (should) already be accounted for on each device itself (although adding surge strips and hence MOV before those devices may prolong their life from such low-energy transients, slightly)

Your summary demonstrates a grasp of the basic concepts.

I have the benefit of a high-school electronics/electrical (both combined into one course) education, and an inquisitive scientific mind. The concepts aren't difficult once you've got the basic understanding of what electricity is.

I think perhaps your wording may have been what was confusing some people? It's hard to explain something with only text without being extremely dry and wordy. Also, I'm summarizing for others' benefit, not trying to teach you anything.

 

[westom]

I have seen computers die from not having surge protectors. They do really work.

If a surge protector does not protect from direct lightning, then it is ineffective. Protection from direct lighting is ... well, how often is your town without phone service for four days while they replace that surge damaged computer? That computer is connected to overhead wires all over town. Therefore suffers about 100 surges with each thunderstorm - without damage. Electronics atop the Empire State Building suffer 23 direct lighting strikes annually - without damage. Protection from direct lightning strikes was routine more than 100 years ago.

You are confusing surge protectors with surge protection. Meanwhile, those rumored (where are your numbers) internally generated surges:

First, if something inside is creating a surge, then the first thing destroyed is the surge creator. And that is the first thing quickly disposed (binned) as defective.

Second, if appliances are creating surges, then you are at the hardware store replacing the least robust appliances such as clock radios, dimmers, and kitchen GFCIs daily.

Third, if it creates a surge, you don't put a protector on everything else. You put it on the appliance that creates surges (see also 'six').

Fourth, a 'whole house' protector is so robust as to make lightning irrelevant. And makes tiny internal surges irrelevant. Unlike a plug-in protector, the 'whole house' protector addresses all types of surges.

Fifth, most internally generated surges are really only noise - tens of volts. A 120 volt protector ignores everything below 300 volts. If in doubt, read the let-through number on its box.

Sixth, if an appliance is generating surges, then the protector is degraded in weeks or months. So replace those protectors many times a year. Which marketing people love to promote. And also applies to 'seven'.

Seventh, a most aggressive internally generated surge is from a typical UPS in battery backup mode. Electricity so 'dirty' as to be harmful to small electric motors and power strip protectors. 'Dirt' made irrelevant by protection already inside all electronics.

Bottom line - those internally generated surges are fears invented by marketing people to increase sales.

 

[westom]

I think perhaps your wording may have been what was confusing some people? It's hard to explain something with only text without being extremely dry and wordy. Also, I'm summarizing for others' benefit, not trying to teach you anything.

I appreciate completely what you are saying. But another factor is at play.

First, advertising works because so many blindly believe the first thing they are told. And then aggressively deny anything provided later even it that new information comes with the reasons why and numbers.

Second, step one to separating myth from fact. Facts should be provided with the always required reasons why and numbers. Unfortunately, many believe only what they are first told because they never demand the reasons why with numbers. One characterisitc of junk science: it is subjective; must avoid numbers.

 

[Swamp Monster]

To westom:

Thanks for clarifying things. Really good explanation.
No more confusion.