[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.