Lightning Strike

[brainz01]

Originally Posted by westom

Apparently you believe a UPS will somehow 'block' a surge. It will not. It does not claim to.

Those 2 cm disks inside a power strip are superior to protection provided by a UPS.

Actually, FWIW, my consumer grade UPSs do claim surge protection. And they appear to provide it by using the same varistors that the power strips use. Are they a perfect solution? Well, they didn't save my networking equipment... I'm curious as to why you say above they can make the situation worse?

Originally Posted by westom

Investigation starts at single point earth ground. Did other earth grounds exist? Did any conductor outside the house enter without making a low impedance (ie less than 10 foot) connection to that earth ground?

Protection is always about connecting a surge on a path that is not destructive.

Effective protection never 'blocks' a surge.

The single point ground rod is interesting to me. My home has a single meter box, two main disconnects, and two main panels -- each has it's own connection to a local ground rod (although the disconnects and meter have the same rod). I just looked at the code/recommended installation online and it looks right to my untrained eye. I'm not sure what else I'm supposed to ground.

You've also got me rethinking the surge protectors I installed (which are at the disconnects for my HVAC units). The more I think about it, these are probably just [big] varistors that look to block the surge through increased resistance. I know you say they can't block a surge, but isn't that exactly what they're supposed to by increasing their resistance with voltage? Do these help or not?

It seems like I should have also installed two whole house surge (4-wire) protectors (one at each main panel). Perhaps those would have better grounded any voltage spikes (at the respective panels) before looking for a path to ground on the circuit branches? Something like this?: https://www.amazon.com/Siemens-FS140-Whole-Protection-Device/dp/B013WINMK6

And while you're sharing your knowledge on lightning/surge protection, what are your thoughts on metal roofs, and how should they be grounded (if at all)?

[dad911]

Originally Posted by westom

Apparently you believe a UPS will somehow 'block' a surge. It will not. It does not claim to. Only emotions, inspired by advertising lies, reinforce that UPS myth.

Those 2 cm disks inside a power strip are superior to protection provided by a UPS.

Meanwhile, protection inside a server's power supply is superior to both.

Defined is damage because that surge was inside. A connection from a cloud (ie three miles up) to earthborne charges (ie four miles distant) was through a tree, then probably through some buried conductor, into a house, destructively through tube sets and alarm panel, and then out four miles to earthborne charges.

That electric current was inside because of a human mistake. A solution always starts by first defining the mistake / defect. What was that destructive path through a house? Investigation starts at single point earth ground. Did other earth grounds exist? Did any conductor outside the house enter without making a low impedance (ie less than 10 foot) connection to that earth ground? If any are yes, then a human all but invited lightning inside.

Those 2 cm disks inside a power strip must somehow 'block' or 'absorb' a surge. Numbers make it obvious - those power strip protectors (and even less protection in a UPS) do not claim to protect from destructive surges. Those will somehow 'block' a surge? Anything that 'blocks' a surge is a scam.

Protection is always about connecting a surge on a path that is not destructive. That means a lightning strike to a tree should have never connected that current into the house.

Effective protection never 'blocks' a surge. Effective protection always connects that current on a path that is not destructive - that is not anywhere inside a house.

Sorry I don't have time to reply, you've convinced me to surround my home with a faraday shield, and convert to solar power so I can get off the grid......

[westom]

Originally Posted by brainz01

Actually, FWIW, my consumer grade UPSs do claim surge protection. And they appear to provide it by using the same varistors that the power strips use.

How many joules does it claim to 'absorb'? It can claim anything in a color glossy brochure or advertising material. Lying there is all quite legal. Only place they must be honest is in numeric specifications.

How many joules does that UPS claim to absorb? Any statement about protection must list that relevant number. Hundreds? Electronics routinely convert a near zero surge into rock stable, low DC voltages to safety power semiconductors. So where is superior protection? Already inside appliances.

A larger surge (too tiny to damage any appliances) can also destroy near zero joules in a UPS - no protection. That surge continues into appliances where it is made inert. Grossly undersizing a protector get the most naive among us to recommend it and buy more. UPS has near zero joules.

It has protection. Near zero means protection virtually does not exist. But just enough to promote it as 100% protection to naive consumers.

No surge protector does effective protection. And a surge protector protects from all surges including lightning. Why are both sentences true? Because terms are subjective. A protector adjacent to appliances does not claim effective protection and can even make appliance damage easier.

A completely different device, called a surge protector, is complete protection from surges including direct lightning strikes. A term 'surge protector' describes two completely different devices that do completely different things. Always grasp numbers.

Spend massively on a UPS or plug-in protector to have no effective protection. Spenc about $1 per protected appliance to protect all appliances from all surges (including direct lightning strikes) for many decades. How would you know the difference? You don't. We still have not provided enough numbers.

All homes are required to have earth ground. That is necessary to only protect human life. Codes only discuss what protects humans. Code says nothing about protecting appliances.

Appliance protection means that same earth ground must be low impedance. Follow that bare copper, quarter inch wire to an earth ground electrode. If it goes up over the foundation and down to earth, then it is too long - excessive impedance. It has sharp bends over the foundation - excessive impedance. If it has splices or inside metallic conduit - excessive impedance. It is a low 'resistance' connection to earth - to meet code - to protect humans. That hardwire has excessive 'impedance' - is not a best connection to earth to protect appliances.

Best is to route that hardwire through a foundation and down to earthing electrodes. Separated from other non-grounding wires. No sharp bends. Every foot shorter increases protection.

Now a 'whole house' protector will connect surges (ie direct lightning strikes) to earth. Now hundreds of thousands of joules harmlessly dissipate outside. Now best protection already inside every appliance (and near zero joules in a power strip or UPS) are protected.

Note what an effective protector does. It does not 'block' or 'absorb' a surge. It connects a surge to the only item that harmlessly 'absorb' hundreds of thousands of joules. Effective protectors are always connecting devices. The less energy a protector absorbs means a better protector. But again, it must always connect low impedance to the item that does protection - earth ground.

An AC utility demonstrates good, bad, and ugly (preferred, wrong, and right) solutions at:
https://www.duke-energy.com/energy-education/power-quality/tech-tips
then select Tech Tip 8.

If all main panels do not make that low impedance connection to earth, then two separate earth grounds means a best connection from cloud to earthborne charges is up through one ground, destructively through household appliances, and down to earth on that other ground. Again, the term 'single point earth ground' is that specific, clear, and defines all protection.

Neither UPS nor plug-in protectors connect low impedance to that earth ground. Both will avoid all this discussion to protect obscene profit margins. Yes, symptoms of a scam.

Resistance is futile. Impedance is the critical factor. A topic that ineffective protectors must avoid discussing.

Surges are a current source. That means voltage increases, as necessary, to blow through anything that foolishly tries to stop it. Anything that would 'block' a surge is promoted only to consumers who want to be scammed. Who automatically believe what they are ordered to believe. Who ignore specification numbers. dad911 demonstrates a mindset (or reading abilities) of one who all but wants to be scammed.

All this is simple - well understood over 100 years ago. Which is why this post is so short. Reality always requires this much reading; if not found in soundbytes that promote plug-in solutions. But we have not yet defined parameters for an effective protector. Lightning can be 20,000 amps. So a minimal 'whole house' protector is 50,000 amps. Then a protector remains functional for many decades after many direct lightning strikes.

That Siemens is one example. Sufficient sized 'whole house' protectors are also found in big box hardware stores even for $60. Ironically, the same product from the same store has sometimes cost more on their internet site.

That defines protector life expectancy over many surges. The above requirements of a connection to and quality of earth ground defined protection during each surge.

More numbers. An IEEE standard defines a 'whole house' solution as doing 99.5% to 99.9% of the protection. It is not perfect. Plug-in protectors may add another 0.2% protection (and are ineffective if the 'whole house' solution is not implemented). Then the IEEE makes another statement:

Still, a 99.5% protection level will reduce the incidence of direct strokes from one stroke per 30 years ... to one stroke per 6000 years ... Protection at 99.5% is the practical choice.

Nothing new here. This is how protection was done over 100 years ago in facilities that could not have damage. Your telco CO suffers about 100 surges with each storm. How often is your town without phone service for four days while they replace that switching computer? Never? Exactly.

Homeowner spends about $1 per appliance to have similar protection from something that occurs maybe once every seven years. Why would anyone spend tens of times more money on plug-in profit centers? Consumers, who want to be scammed, ignore spec numbers.

[westom]

Originally Posted by dad911

..., you've convinced me to surround my home with a faraday shield, and convert to solar power so I can get off the grid......

Informed consumers know that same 'whole house' protection is even more necessary with solar power. Informed consumers have no problem reading what is only paragraphs. Since the informed know any answer without reasons why is bogus.

Others wait to be ordered what to think.

[PetrolBlueSC]

Son of tabs has arrived.