Automation system hit by lightning

[NeverDie]

@rockinarmadillo
Thanks for your OP and your inventory of damage.  I had overlooked the recirc pump as a potential pathway for a surge to re-enter the electrical system (since obviously it's normally plugged in to power it).
 
I suppose it would be nice to have a fiberoptic link going from my TimeWarner coax cable drop, and to run the exterior unit on battery during a lightning storm to isolate it.  I suppose it would probably be easier to put the cable modem itself outside in the same enclosure and run a short fiberoptic link from that to the other side of the garage wall, since the modem has an Ethernet output.  I do unplug my irrigation system during lightning storms though, as that is easy to do.  Maybe someday I'll switch to wireless latching valves to remove the irrigation control wires from even entering the garage, as I do worry a little that it might spark over to the electrical system due to sheer proximity.
 
This stuff really does happen.  A friend recently related how he had unplugged his TV during an electrical storm, but it got fried anyway because of the surge that came in through his cable-tv wiring.   That's just nasty.

 

[westom]

 Undersized protector fails as indicated by its light." - what does that even mean?
 
On my outdoor cable I am happy to use a clamping voltage that is a percentage above the expected circuit voltage and has been used successfully in the past. Ditek has devices that they recommend for rs-485 and IP cables and that is good enough for me.

 
1) Clamping voltage between what and what?  For example, a 5000 volt transient can enter on AC hot (black) wire.  Clamping (let-through) voltage on a plug-in protector is typically 330 volts.  That means a black hot wire is at 5000 volts.  White (neutral) and green (safety ground) wires are now at 4670 volts.  Protector has clamped 330 volts.  Protector has simply put 4670 volts on other wires giving that surge even more potentially destructive paths into adjacent appliances.
 
2) A protector has a light that says when the protector has failed.  That light does not report acceptable failure modes.  That light only reports a type of failure due to a grossly undersized protector.
 
Both are examples of what they forget to mention when promoting undersized protectors with massive profit margins to naive consumers.
 
Everyone - even the electrically naive - need an answer to one question.  Where do hundreds of thousands of joules harmlessly dissipate?  Any recommendation that cannot answer that question - with numbers - is potentially a scam.  Same applies to an adult seeking any technical answers to other subjects.  Recommendation without perspective (ie numbers) is best suspect as a scam.
 
Does your Ditek make a low impedance (ie less than 10 foot) connection to a single point earth ground?  if not, then a 'whole house' protector from that better manufacturer has been compromised.  An answer to where hundreds of thousands of joules harmlessly dissipate means identifying and inspecting what actually does protection.  Not a protector.  Effective protectors only connect to what does the protection - earth ground.
 
Where are hundreds of thousands of joules absorbed?  A properly installed Ditek will answer that question.  Does your Ditek have that essential low impedance (ie less than 10 foot) connection to earth?  An answer defines well over 95% of your hardware protection.  Necessary to even protect plug-in protectors.
 
Any layman can do that inspection.  Do you need additional information to perform it?

 

[westom]

 I still want access to lighting controls, though, so I leave the dedicated automation platform connecedt and powered on, albeit with a surge protector and a UPS.  If the low-end platform gets fried, at least the replacement cost is low. I'd feel much worse if a vmware megabox got hit.  

 
High end equipment is left unprotected or possibly at greater risk.  Adjacent protectors (as discussed in that previous post) can make damage easier IF 'whole house' protection is not properly earthed.
 
Nothing inside will protect from typically destructive surges.  You have connected an automated platform to devices that do not claim to protect from typically destructive surges.  It is a common mistake.  Most forget to read spec numbers.  Again, protection is always about where hundreds of thousands of joules are harmlessly absorbed.
 
How many joules does that plug-in protector claim to absorb?  A thousand?  How many joules does that UPS claim to absorb?  Even less - hundreds?  Where is protection from surges that actually do damage - ie hundreds of thousands of joules?  Never ignore numbers.  Best is to ignore any recommendation that does not come with numbers.
 
Ditek answers that question because it makes a low impedance (ie less than 10 foot) connection to earth ground (if properly installed).  Neither that power strip nor UPS make that connection; neither claim effective protection.
 
Will a fiber optic link provide effective protection?  Only if all other wires (including AC wires) are also fiber optic.  For over 100 years, protection from direct lightning strikes was performed without fiber and without those other more expensive solutions.  That same protection costs tens of times less money compared to a power strip or UPS.  Best protection that also costs less money is obvious - it makes a low impedance (ie less than 10 foot) connection to earth ground.

 

[westom]

So transient protection is not only lightning protection.  Different (but related) strategies are used to mitigate various types of EMI.  Filtering and shielding are generally used for RF immunity.  Transzorbs, spark gaps, and MOVs are used to absorb or divert transients.  ESD can be mitigated with spark gaps, small caps, and diode clamps on the PCB.  Isolation can be used to break paths, also.

 
You are discussing what can be considered and discussed only AFTER a 'whole house' solution has been implemented.  Properly earthed 'whole house' protection does 99.5% to 99.9% of the protection.  That means lesser transients (ie mythical surges created by household appliances) would also be quashed.  if that 'whole house' solution is not implemented, then supplemental protection is ineffective.
 
Undersizing an MOV protector means a surge that would only create 330 volts, instead creates over 900 volts (as the protector sacrifices itself).  Read MOV datasheets to appreciate it.  MOVs never operate at one voltage.  Voltage increases drastically with current.
 
Most of your concerns are irrelevant to and too complicated for this thread.  This is about what does almost all protection for a homeowner.  And what must exist to even protect ham radio equipment (as discussed in so many ham sites including QST magazine and 'tower talk'. 
 
Protection is always about how a current source (the surge) connects to earth.  (Do not confuse a current source with a voltage source.)  Either harmlessly outside or destructively inside via appliances.
 
Protection is based in what Franklin demonstrated in 1752.  Again, no protector does protection. Each layer of protection is defined what what harmlessly absorbs energy.  Protectors are connecting devices to what does that protection - single point earth ground.  That (and not the protector) should have most of everyone's attention and questions..

 

[NeverDie]

High end equipment is left unprotected or possibly at greater risk.  Adjacent protectors (as discussed in that previous post) can make damage easier IF 'whole house' protection is not properly earthed.
 
Nothing inside will protect from typically destructive surges.  You have connected an automated platform to devices that do not claim to protect from typically destructive surges.  It is a common mistake.  Most forget to read spec numbers.  Again, protection is always about where hundreds of thousands of joules are harmlessly absorbed.
 
How many joules does that plug-in protector claim to absorb?  A thousand?  How many joules does that UPS claim to absorb?  Even less - hundreds?  Where is protection from surges that actually do damage - ie hundreds of thousands of joules?  Never ignore numbers.  Best is to ignore any recommendation that does not come with numbers.
 
Ditek answers that question because it makes a low impedance (ie less than 10 foot) connection to earth ground (if properly installed).  Neither that power strip nor UPS make that connection; neither claim effective protection.
 
Will a fiber optic link provide effective protection?  Only if all other wires (including AC wires) are also fiber optic.  For over 100 years, protection from direct lightning strikes was performed without fiber and without those other more expensive solutions.  That same protection costs tens of times less money compared to a power strip or UPS.  Best protection that also costs less money is obvious - it makes a low impedance (ie less than 10 foot) connection to earth ground.

Let's cut to the chase:  how many dollars would it cost to retrofit a typical wood-framed house with the type of bulletproof protection you're talking about?  If it's within the realm of reason, then I'm interested.  On the other hand, if it isn't cost effective, then it's not at all interesting.  A TV station may need to take extreme measures so that they can stay on the air through a lightening storm.  I don't.

 

[dementeddigital]

You are discussing what can be considered and discussed only AFTER a 'whole house' solution has been implemented.  Properly earthed 'whole house' protection does 99.5% to 99.9% of the protection.  That means lesser transients (ie mythical surges created by household appliances) would also be quashed.  if that 'whole house' solution is not implemented, then supplemental protection is ineffective.
 
Undersizing an MOV protector means a surge that would only create 330 volts, instead creates over 900 volts (as the protector sacrifices itself).  Read MOV datasheets to appreciate it.  MOVs never operate at one voltage.  Voltage increases drastically with current.
 
Most of your concerns are irrelevant to and too complicated for this thread.  This is about what does almost all protection for a homeowner.  And what must exist to even protect ham radio equipment (as discussed in so many ham sites including QST magazine and 'tower talk'. 

 
I never claimed otherwise.  We can agree that a Type 1 or Type 2 surge protector is certainly the first line of defense.  This thread also discussed long runs of data lines which leave one structure and go to another.  A whole-house suppressor won't protect those.  A whole-house suppressor also doesn't eliminate the need for Type 3 devices at sensitive electronics.  It's good for big hits, but the clamping voltage tends to be higher than it is in the Type 3 devices.
 
Living in the lightning capital of the US, I've experienced odd behavior on electronics even with whole house protection.  Thankfully there have been no direct hits or catastrophic damage to my house, but I was inside another house which took a direct hit to the chimney.  It traveled down the metal drywall corner and blew out a chunk of the wall.  It also conducted to a nearby outlet and damaged a stereo on another outlet in the room.  All of this damage was not near the breaker panel, so a whole-house suppressor wouldn't have prevented damage.  A Type 3 device at the stereo might have helped, but it's hard to know for sure.
 
I tend to think of EMC topics as related.  In product development, they are designed as a system and they are usually tested in one trip to the EMC test lab.  (Or more trips, if you didn't get it right the first time.)  Surge protection is only one aspect of EMC.  My concerns might not be relevant for you, but they are certainly not irrelevant for me.  I have RFI concerns too, and in my mind, surge protection and filtering go hand-in-hand.

 

[dementeddigital]

Let's cut to the chase:  how many dollars would it cost to retrofit a typical wood-framed house with the type of bulletproof protection you're talking about?  If it's within the realm of reason, then I'm interested.  On the other hand, if it isn't cost effective, then it's not at all interesting.  A TV station may need to take extreme measures so that they can stay on the air through a lightening storm.  I don't.

 
This is a pretty good article which compares a few different whole-house protection devices.
 
With one of those nice ones, you're looking at $100 - $300 for the device.  They aren't complicated to install, but you probably want an electrician to install it.  It should take him less than an hour.
 
I don't have one of those fancy ones.  Mine is an older LA-302 device from Delta.  It has no LEDs and it doesn't protect Neutral-to-Ground, but it seems OK.  They can be had for about $50, and they have good energy ratings.

 

[mikefamig]

dementeddigital
 
thanks for the link it was a good read
 
Mike.

 

[westom]

Let's cut to the chase:  how many dollars would it cost to retrofit a typical wood-framed house with the type of bulletproof protection you're talking about?  If it's within the realm of reason, then I'm interested.  

 
First, nobody said this is bullet proof. Since humans are involved.  But if using a plug-in protector or UPS (what another mistakenly calls a Type 3 protector), then no effective protection.  And fire is a possibility.
 
Second, a house is not retrofitted.  Nothing inside the house need be modified.  Protection is installed at the service entrance.  For example, if renting one from the electric company, then the girl who reads the meter might install it.
 
'Whole house' protectors are sold even in Lowes and Home Depot for about $50.  Earth ground electrodes cost about $10. Anyone comfortable with working in a breaker box can install one. So it is sold in better big box stores.  Otherwise one must hire an electrician.  Most of that cost is paying for the electrician to drive there.  Effective protection is installed that quickly - assuming the house already has a required earth ground.
 
Protection means every wire in every incoming cable (including wires from other outbuildings) must connect to earth ground.  Cable (if properly installed) already has 'whole house' protection installed for free by a cable company or dish installer.  That is a hardwire connected low impedance (ie less than 10 feet) to an earth ground electrode.  Telephone cannot connect directly.  So the telco installs a 'whole house' protector (inside the NID) that also must connect low impedance to earth.
 
Installation is that simple.  And costs tens of times less money compared to plug-in solutions.

 

[westom]

 We can agree that a Type 1 or Type 2 surge protector is certainly the first line of defense.  This thread also discussed long runs of data lines which leave one structure and go to another.  A whole-house suppressor won't protect those.  A whole-house suppressor also doesn't eliminate the need for Type 3 devices at sensitive electronics.  It's good for big hits, but the clamping voltage tends to be higher than it is in the Type 3 devices.

 
First, Type 1, 2, 3, etc define human safety.  It says nothing about protection.  Since plug-in protectors are undersized, then the chance of fire increases when located in a Type 1 or 2 location.  Numbers (that were ignored) makes that obvious.  How does its hundreds or thousand joules absorb a surge that is tens or hundreds of thousands of joules?  So Type 1, 2, 3, etc was created to make fire less likely.  Fire is a serious problem with undersized (plug-in) protectors.
 
Second, appliance protection is never about 'Type'.  Protection is always about how that protector connects to earth.  If the discussion does not mention THE most critical item in a surge protection system - and with numbers - then the recommendation is best considered bogus.
 
For example, a SteveJenkins citation ( http://www.stevejenkins.com/blog/2014/10/whats-the-best-whole-house-surge-protection/# ) does not discuss earth ground.  He makes no effort to describe what a protector really does.  And he does not even know that 'whole house' protection already exists on cable, dish, and telephone as required by codes and other standards.
 
He mistakenly believes a protector does protection because hearsay and advertising say that.  He does not even know of (discuss) the 'primary' surge protection layer.  So much misinformation or human mistakes are posted that I hardly know where to begin.  But again, surge damage is due to humans making mistakes.
 
Third, a direct lightning strike to AC wires far down the street is a direct strike incoming to every household appliance.  Protection already inside appliances makes other, lesser surges irrelevant.  A properly installed 'whole house' protector also makes those lesser transients irrelevant.  But 'secondary' and 'primary' protection layers must exist to protect appliances and ineffective Type 3 protectors.
 
His first example was damage directly traceable to human mistake.  He assumed that because nothing was damaged, then an incorrectly installed 'whole house' protector must have done protection.  In reality, each appliances probably protected itself.  We know this.  He did not provide numbers.  That burned 'whole house' protector was less than 50,000 amps - his mistake..  So it fried.  That citation demonstrates why it failed.  He ignores all critical numbers.  No numbers is why humans make mistakes and are easily scammed.  No numbers is also why that Type 3 protector does not provide effective protection - and are obscenely profitable.
 
Fourth, protection already inside every appliance makes a Type 3 protector unnecessary.  If a 'secondary' protection layer (what was called Type 1 or Type 2) does not exist, or if a 'primary' protection layer does not exist, then superior protection inside appliances can be overwhelmed.  Protection is defined by each layer's earth ground.  He never once discussed THE most critical item in every surge protection layer - earth ground.
 
"Type 3" protectors have no earth ground.  How does it do protection from typically destructive surges?  It doesn't.  It is for a type of surge surge that typically does no damage.  And it must be protected by a 'whole house' protector.   More numbers.  A 'whole house' protector is defined in IEEE Standard as doing 99.5% to 99.9% of the protection.  Those plug-in protectors may be an additional 0.2%.  Why are expensive protectors also least effective?
 
SteveJenkins recommends some of the better 'whole house' protectors - part of the 'secondary' protection layer. But he does not say why.   'Whole house' protectors are provided by companies known for better integrity including Intermatic, Square D, Ditek, Siemens, Polyphaser (an industry benchmark), Syscom, Leviton, ABB, Delta, Erico, General Electric, and Cutler-Hammer.  A direct lightning strike can be 20,000 amps.  So a minimal 'whole house' protector must be 50,000 amps.  Effective protectors do not fail even with direct lightning strikes.  Protection is installed, first and foremost, so that direct lightning strikes damage nothing - not even damage a protector.
 
Fifth, dementeddigital details another example of human mistake.  He all but invited a direct strike into the house.  So a surge even conducted on used a drywall metal bead.  His stereo suffered damage.  No plug-in protector claims to protect from that type of surge.  But it is called a surge protector.  Only speculation assumed it might protect a stereo.  Assumption does not replace knowledge with numbers.
 
Lightning rods protect the structure.  'Whole house' protection protects appliances.  Both are only as effective as their earth ground.  Because he did not earth lightning BEFORE it could enter, then a human mistake resulted in drywall and stereo damage.
 
Sixth, by ignoring spec numbers, he assumed the clamping voltage of 'whole house' protection is higher than plug-in protectors. Reality - both have a 330 let-through voltage.  Meanwhile a hardwire that protects cable has a higher clamping voltage?  Of course not. One must learn numbers (ie 330 volts) before making accusations.  Actual clamping voltage of a 'whole house' solution is even less because it is connected low impedance to earth.  What was the clamping voltage of his plug-in protector?  Previously discussed with numbers.  "That means a black hot wire is at 5000 volts.  White (neutral) and green (safety ground) wires are now at 4670 volts."   
 
Voltages at a properly earthed 'whole house' solution can rise to only hundreds of volts. Lower voltages are provided by properly earthed protection.  Voltage can be higher if only using pljg-in protectors.  Plug-in protectors do so little - maybe add 0.2% of the protection.
 
Seven, long runs of data lines which leave one structure and go to another are routine without damage. It exists in every town.  In every location where long data lines exist, the 'whole house' solution is routine.  Otherwise a lightning strike to one structure is a direct strike to appliances in the other. That is why your telco installs a 'whole house' protector for free.  How many others (who made recommendations) even knew that protector exists?  Why not?
 
Eight.  Separation between protector and appliance also increases protection.  Telcos want their protector to be up to 50 meters distant from the $multi-million switching computer - to increase protection.  Note who actually knows these numbers due to learning the science as well as actual experience.  Protection increases with separation between protector and appliance.  Protection increases with less separation between protector and earth ground.
 
A protector is only as effective as its earth ground.  So informed home owners spend maybe $60 for a 50,000 amp 'whole house' protector.  The inspect a low impedance (ie less than 10 foot) connection to THE most critical item that does protection - single point earth ground.  Best is to ignore silly nonsense about Type 1, 2, 3, etc protectors.  That says nothing about surge protection.
 
 Unfortunately so much misinformation exists that I hardly knew where to begin.  We know that StevenJenkins article is not based in knowledge since he did not even discuss THE critical number for an effective protector - ie 50,000 amps.  No numbers is the first indication of bogus recommendations and junk science reasoning. Plenty of questions should now exist.  For example, what must be inspected in the 'primary' protection layer?  We know why expensive type 3 protectors do so little.  A protector is only as effective as its earth ground.

 

[dementeddigital]

Westom, you're funny, man.  You should change your screen name to EarthGround.  I bet it's available.
 
The types in this case define the location of the SPD.
 
From NEMAsurge.org:
 
Type 3 SPDs(Listed) – These SPDs are called, ‘Point of Utilization SPDs’, which are to be installed at a minimum conductor length of 10 meter (30 feet) from the electrical service panelunless they are evaluated at Type 2 SPDs (that is, they receive a Nominal Discharge Current Rating of 3 kA minimum). Typically, these are cord-connected surge strips, direct plug-inSPDs, or receptacle-type SPDs installed at the utilization equipment being protected (i.e. computers, copy machines, etc.).
 
I would encourage you to have a read of that site.  There is a lot of good information there, published by engineers.
 
I disagree with your dismissive thoughts about the type 3 SPDs.  They have a place in an overall surge protection strategy. 
 
Here is another nice paper discussing this topic.
 
In any case, I'm done with this thread.  It has been interesting on many levels.

 

[westom]

The types in this case define the location of the SPD.
 
From NEMAsurge.org:
 
Type 3 SPDs(Listed) – These SPDs are called, ‘Point of Utilization SPDs’, which are to be installed at a minimum conductor length of 10 meter (30 feet) from the electrical service ...

 
Do read your own quotes?  That SPD in a Type 2 location creates human safety threats such as fire.  'Type' says nothing about appliance protection.  If it did, then you said why it does protection - with numbers. You have no idea what protectors do. You did not even read your own lightningsafety.com citation hoping it agrees with your assumptions and wild speculation.
 
Protectors are only connecting devices to what does protection. Advertising says something different. Hearsay and advertising (propaganda) easily play the many who cannot separate myths and lies from honest technical facts.  It is not hard.  Myths and lies provide no numbers.  In this case, the lies will not even discuss where hundreds of thousand of joules are harmlessly absorbed - to protect profit margins.
 
Please show me one Type 3 specification that claims protection from destructive surges.  Please show me one specification number that defines protection from lightning. Never provided. You can't for two simple reasons.  First, you have no idea what to look for (propaganda forgets to teach that).  Second, because no such numbers exist for Type 3 protectors.
 
A 1994 IEEE research paper defines the problem - with plug-in (point of connection) protectors.  Please learn this science before making recommendations:

Conclusion:
  1) Quantitative measurements in the Upside-Down house clearly show objectionable difference in reference voltages.  These occur even when or perhaps because, surge protective devices are present at the point of connection of appliances.

In short, plug-in protectors can even make appliance damage easier.  Paper makes obvious why earthed protectors do protection.  And why completely different devices (unfortunately also called surge protectors) can make damage easier.
 
Of course, that paper did not discuss other problems with unprotected (what you call Type 3) protectors.  Fire.  A problem so massive that APC recently admitted that some 15 million plug-in protectors must be removed immediately. Just another reason why informed homeowners earth a 'whole house' solution for tens or 100 times less money. To increase that protection, upgrade the only item that defines surge protection - single point earth ground.
 
But again, that means unlearning many lies and myths. And learn that honest recommendations come with spec numbers. 
 
If dementeddigital wanted to learn - and he has almost no knowledge beyond what is taught by advertising - then he would have also asked about the 'secondary' and 'primary' surge protection layers.  He only wants to argue. Those who want to learn would ask about what is critical to protect household appliances and 'Type 3' protectors. Since every protection layer is only defined by one thing - earth ground.
 
Citation from lightningsafety.com contains quotes that were conveniently ignored: 

.. three requirements of the service entrance SPD. ...:
1) To suppress the larger surges from the outside environment to levels that would not be damaging to equipment at the service entrance, or to equipment (air conditioning, wired-in appliances) directly connected to the branch circuits. 
2) To reduce the surge current to the downstream SPDs (including multiport SPDs). 
3) To stop the large lightning currents from passing into the house wiring system and damaging the wiring or inducing large voltages that would damage electronic equipment.

 
What does all three?  A properly earthed 'whole house' protector. What does not do any?  A 'magic box' Type 3 protector. Point 2 says 'whole house' protection is even needed to protect that near zero "Type 3" protector. Why did he ignore that?
 
 

2.3.1 Grounding
An effective, low-impedance ground path is critical for the successful operation of an SPD. 

 

Citation says exactly what I have been saying.  Why?  Think about it for a minute.  No need to quote any more since it was  posted previously - with numbers.
 

2.3.2 Lead Length
To achieve optimum overvoltage protection, the connecting leads between the SPDs and the panel or protected equipment should be as short as possible and without sharp 90-degree bends.   

 

How curious.  A connection to earth ground must be low impedance.  Who noted that (less than 10 feet, no *sharp bends*, not inside metallic conduit, etc) repeatedly?  Who did not even read his citation?
 
What does figure 8 demonstrate?  A plug-in (Type 3) protector, without a 'whole house' solution, earths a surge destructively via some nearby appliance.  They even provide a number for the resulting damage - 8000 volts.  Why recommend a protector that may earth a surge 8000 volts destructively through a nearby TV?  He also does not comprehend simple pictures. Propaganda targets some who do not read their own citation.  And who ignore numbers.
 
OP had damage to a detached garage and household appliances. Classic when a 'whole house' solution is not implemented in both garage and house.  An informed investigation starts at the only item that does protection - single point earth ground.  Apparently even sprinkler wires were not properly earthed (via a protector).
 
Protection is always about how a surge gets harmlessly to earth. Lightning rods protect structures by connecting lightning on a better path to what does that protection - earth ground.  'Whole house' solution protect appliances by connecting lightning on a better path to what does that protection - earth ground.  What is probably missing at both ends of each wire between garage and house?  A properly earthed 'whole house' protector. 
 
Useful advice, from someone who actually did this stuff, starts by first inspecting a single point earth ground for both garage and house.  And how every wire in every incoming cable makes a low impedance connection to that earth ground.
 
A garage strike is a direct strike to all appliances in the house - if above protection was not implemented.  Protection from this type of damage was routinely installed long before semiconductors existed. 

 

[Del91574]

You are discussing what can be considered and discussed only AFTER a 'whole house' solution has been implemented.  Properly earthed 'whole house' protection does 99.5% to 99.9% of the protection.  That means lesser transients (ie mythical surges created by household appliances) would also be quashed.  if that 'whole house' solution is not implemented, then supplemental protection is ineffective.
 
Undersizing an MOV protector means a surge that would only create 330 volts, instead creates over 900 volts (as the protector sacrifices itself).  Read MOV datasheets to appreciate it.  MOVs never operate at one voltage.  Voltage increases drastically with current.
 
Most of your concerns are irrelevant to and too complicated for this thread.  This is about what does almost all protection for a homeowner.  And what must exist to even protect ham radio equipment (as discussed in so many ham sites including QST magazine and 'tower talk'. 
 
Protection is always about how a current source (the surge) connects to earth.  (Do not confuse a current source with a voltage source.)  Either harmlessly outside or destructively inside via appliances.
 
Protection is based in what Franklin demonstrated in 1752.  Again, no protector does protection. Each layer of protection is defined what what harmlessly absorbs energy.  Protectors are connecting devices to what does that protection - single point earth ground.  That (and not the protector) should have most of everyone's attention and questions..

Funny how this defies the whole Ohm's law. Voltage and amperage are inverse proportional.

 

[Del91574]

Clamping voltage and response times are irrelevant.  Clamping voltage and response times for all effective protectors are more than sufficient.   Protection is defined by an impedance to and quality of earth ground.  
 
Better would have been a protector that connects each "low voltage wire to sprinklers" to single point earth ground.  Then a direct strike to sprinklers need not connect to an earth ground electrode destructively via a sprinkler controller.
 
Protection is always about the path a surge current takes to earth ground.  And about making that earth ground a best and most desirable path.  Then current need not pass through (and damage) any other hardware.

Really....can you describe your experience and background that justifies these claims?
 
Clamping voltage and response time is the whole entire game. You want the voltage to be just above the operational system voltage and with a fast response time. Too high a voltage or too slow a reaction time, you're going to damage sensitive components. If SPD's were "all created equal" why are different clamping voltages and RT's offered? Marketing claims?
 
I've dealt with improperly selected SPD's and once the clamping voltage was adjusted, the damage stopped, other than the self-sacrificing SPD's.
 
The impedance and quality of the EG is only the beginning portion of the equation. You have a voltage differential on the circuits connected to the control equipment, no matter what the ground is, there's going to be voltage due to the difference in potential of the cabling and system.....which is what the surge actually is.
 
Oh, and BTW, the "surges" that the CATV's and Telco's install are NOT to protect the HO's equipment from surges, it's to protect their equipment to a known extent.

 

[dementeddigital]

Do read your own quotes? 

 
I sure do.  You might want to start doing so, too.  You're tilting at windmills.
 
First, no one said to use a type 3 device in a type 2 location.  Not only would that be silly, but if you think about if for more than a few seconds you'd come to realize it's almost impossible.  The type 3 devices are point-of-load - they plug into an electrical outlet (or they are the outlet itself).  Type 2 devices go on the load-side of the panel, and are generally wired directly in.  If you also read some of my earlier posts without just looking for points to argue, you might not have skipped over the part where I agreed that it makes sense to install a type 1 or type 2 device first, and then look at the rest of the system.  No one in this thread seems to disagree on that point.  No one.
 
No one ever said that type refers to appliance protection.  Where did you come up with that?  Type in this case refers to the location where the SPD is installed.  And you blame me for not reading?  Really?
 
No residential surge protector is going to claim protection from a direct lightning hit.  If you spent a few minutes with Google, you might find that numbers do exist for type 3 devices, however.  Leviton, for example, specifies one of their type 3 devices at 18kA L-N, 9kA L-G, and 9kA N-G.  They also provide joule ratings and breakdown voltages - everything a happy homeowner might want to reference to see how that device might perform in his application.  (He knows the other details of his application.  The manufacturer of the SPD does not.)  As I said before and you somehow missed, type 3 devices are supplemental protection, but they do add robustness to the overall surge protection system.
 
Plug-in protection CAN make damage easier ONLY if you don't pay attention to the other paths.  The simple picture which you claim I didn't comprehend clearly shows the problem.  Having a plug-in SPD on a TV, but not adding any protection to the cable (referenced to the same location as the plug-in SPD for that device) can cause issues from a voltage difference between the AC wires and the cable during a strike.  It's clear that a voltage difference can mean current flow through the TV in ways that the circuit designer didn't intend, causing damage.  Consumer electronic devices are often not tested to high levels of transients like commercial systems are.  As I said before, calling their internal protection "robust" is a stretch, at best.  Using a plug-in SPD at a TV which includes protection for all lines going into the TV will IMPROVE the TV's chances of survival.  You just need to pay attention to the other paths a little.  The other simple pictures there which you neglected to mention (or didn't comprehend) show how it is quite easy to add some effective protection for the devices at the point of load.  Maybe I can teach an old dog some new tricks?
 

If dementeddigital wanted to learn - and he has almost no knowledge beyond what is taught by advertising - then he would have also asked about the 'secondary' and 'primary' surge protection layers.  He only wants to argue.

 
Jeez.  I didn't want to argue before, but I do now.  Of course I want to learn, but I'm not completely ignorant on the topic either.  I'm an electrical engineer working in the field for over 20 years, and I don't completely suck at it.  My name is on a few patents.  Part of that experience has included designing MOV and GDT based surge protection for outdoor, commercial LED street lighting.  I've designed many electronic products which need to survive transients.  I'm not saying that to see who has a bigger...whatever.  I'm just not completely ignorant on these things.  You're certainly quick to belittle others, and I'm done giving you any respect at this point.
 
As I said before - no one has asserted that type 3 devices be used in place of a type 1 or type 2 device.  No one.  I will posit that using type 3 devices IN ADDITION TO a type 1 or type 2 device will make surge protection more robust.  Feel free to disagree, but you'd be wrong.
 
Yes, you've noted the Earth ground repeatedly.  It is important.  No one is arguing otherwise.  NO ONE.
 
HOWEVER - you keep saying that the Earth ground is what provides the protection.  That isn't true.  The Earth ground is just the path where the lightning is trying to go anyway.  It's the SPD which conducts and provides a lower-impedance path for the surge rather than through other things in the house.  So the protection comes from the "P" in the SPD.  It is the SPD which is the device which conducts at a certain voltage, diverting current to the Earth ground.  It's a circuit, and it takes both the ground and the SPD, but the ground is just a reference point and a path.