Whole house protection would be best. But, if you don't have it I'd rather a surge protector that doesn't divert to ground, is not sacrificial and meets the highest specs of UL's optional testing. SurgeX and others fit that criteria. With the exception of SurgeX and a couple others most of the other companies that make this type of protection are targeted at more critical markets like hospitals.

So if you are going to use a unit without whole house protection I'd still use a SurgeX (series) type solution over an MOV unit. In the ideal world a whole house surge protector should be the first line of defense and if you are going to have only one surge protector it should be a whole house one.

Joule ratings are an approximation, similar to nominal impedance in speakers. It gives everything in one number but in reality it varies.

Depends on what problems the local system has. If the surges are gentle and normal fluctuations in the supply voltage, it's simple. If the area has major over-voltage and hard spikes from a nearby industrial plant, it's more difficult. If lightning is causing the problems, good luck.

Furman's products with SMP are non-sacrificial as well.

Any protector that stops or absorbs a surge simply causes the surge voltage to increase. No proven protection has ever done that. But most are only recommending what advertising has told them to believe.

Protection starts by understanding how all proven protection works. Starting with what was taught in elementary school science. Lightning strikes a church steeple to connect the cloud to earth. Wood is an electrical conductor. But not a very good conductor. A 20,000 amp lightning bolt therefore creates a high voltage. High school physics. 20,000 amps times a high voltage is high energy. Church steeple damaged.

Franklin eliminated damage with a lightning rod. Does the rod do protection? Or course not. The rod connects to what does protection. The wire is a good electrical conductor. 20,000 amps creates a near zero voltage. 20,000 amps times a near zero voltage means near zero energy. No building damage.

That is protection of the building. Lightning also strikes AC wires far down the street. That is a direct lightning strike to all household appliances - if current is inside the house. The only protectors that connect low impedance (ie 'less than 10 feet') to earth are 'whole house' type. If earthing and its connection meet and exceed code requirements, then a 20,000 amp lightning strike created near zero voltage.

We protect the building by creating a near zero voltage connection to earth before lightning strikes the roof (or church steeple). We protect appliances by creating a near zero voltage connection to earth before lightning enters the building.

Once inside the building, then nothing stops a destructive hunt for earth via appliances. View the Surgex numbers. Near zero protection. And they also forgot to mention wires that bypass the Surgex; connect a surge directly into a computer or TV.

Once inside, then the best protection is already inside appliances. You can spend $thousands for interior solutions. And still not have that low impedance connection to earth. Only earth is where hundreds of thousands of joules dissipate. How many joules does the Surgex claim to absorb? About 500. Where is the protection? Surgex does not claim to protect from typically destructive surges. Due to superior protection already inside all appliances, Surgex claim to protect from noise.

No protector does protection. A problem for most who want every solution inside a box. Reread those first paragraphs. What harmlessly absorbs hundreds of thousands of joules? What defines all protection? Earth ground. If you do not grasp that, then you are ripe to be scammed.

Facilities that cannot have damage do not waste money on protectors inside the building. The superior solution, that also costs tens or 100 times less money, is a 'whole house' protector properly earthed. Low impedance connection which means a wire length from protector to earth 'less than 10 feet'. Because wire length (not wire thickness) is the most critical parameter. No snake oil. Just fundamental electrical engineering knowledge.

Companies with better integrity sell the superior solution including Square D, Leviton, General Electric, ABB, Siemens, Ditek, Polyphaser, and Intermatic. A Cutler-Hammer solution sells in Lowes and Home Depot for less than $50. Money does not define quality. Science does. Worry little about the protector. Worry most about what defines protection - single point earth ground.

How long will a protector last? Lightning is typically 20,000 amps.  Any protectors that fails (sacrifical) is best called a scam.  A minimal 'whole house' protector is 50,000 amps (and also costs less money).  Direct lightning strikes must not even damage the protector.  50,000 amps defines life expectancy after many surges for the next 10+ years. What defines protection during each surge? Earth ground and that wire connection to earth.

  Worry about protection during each surge and system life expectancy over 10+ years of surges.  Numbers are provided for both.

Never think of protection in terms of a box (ie Furman). Magic boxes promote scams. Protection is about where hundreds of thousands of joules dissipate. Anyone making an honest recommendation will state clearly where those hundreds of thousands of joules dissipate. Most educated by advertising cannot cite numbers.

Above is your secondary protection layer. Each protection layer is defined by what? Earth ground. Also inspect your primary protection layer. Appreciate that an engineer who did this stuff introduces many new concepts that were well understood even 100 years ago. A picture demonstrates what in your primary protection system should be inspected:
[Link: tvtower.com]

A protector is only as effective as its earth ground. Why do protectors without earthing also claim near zero joules? Profit centers are not effective protection.

Gents,

I don't have the time to respond fully, and explain this, so I will do so sometime tomorrow.

Westom has made some technical mistakes in the email above. The amount of energy does not change if the current is high and the voltage low, as compared to the voltage high, and the current low... the strike contains the same amount of energy.

My experience with whole house protection has been less than impressive. While they may work fine for appliances and motors, from my experience they don't clamp quick enough to save electronics. I see houses with lightning rods, whole house surge protection, and enough APC and Panamax products to put a kid through an out of state school. And if the hit is close enough, something is getting fried. I've seen it come in power lines, phone lines, coax, invisible fences (those are the worst), back feed across the house ground, the propane line from the tank out in the yard, the stone on the foundation with a high iron content, and a barbed wire fence that ran close to the house I've seen invisible fence transmitters literally blown off the wall, copper disintegrated inside the jacket but the jacket left in tact, and a house take a direct hit and burn to the round and the same strike fry every electronic device in the neighbors house several hundred yards away even though everything had surge protection.

All you are really going to protect from are the surges that originate inside the home and lows and spikes on the regular utility service.

Stop worrying about lightning and learn how to work well with your client's homeowners insurance

The first most important thing is that it clamps at 140 volts or less!

Alot of the cheaper units clamp at over 300 volts.  So yes the cheep units will keep the device from catching on fire during a lightning strike, but what happens when you run over 300 volts through anything with sensitive electronics?

'Sensitive electronics' are designed to withstand 300V surges.

The lowest defined clamping voltage in UL1449 is 300v. I believe that is why you see on most product spec sheets

Fins is absolutely correct. If you take a direct lightning hit or an indirect one nearby where the energy is going to enter your home from another means besides the utility line no amount of surge protection is going to help. And if it is strong enough on the utility line the surge protection won't help either.

We had a house on a mountain with 20k of lighting rods and lightning arrestors and his house still got hit. It took out a bunch of stuff like his water pump, ovens, appliances as well as electronics.

Good insurance is the solution for this type of damage.

That post says all facts and numbers were ignored. No lightning rod does protection. What does protection? What does a lightning rod connects to? He never once mentioned earth. He completely ignored over 100 years of well proven science. He repeated only what advertising told him to believe.

Clamp fast enough? Read manufacturer spec numbers. Less expensive and superior protectors respond in nanoseconds to surges that are microseconds. A time that may increase when a human foolishly ignores numbers such as 'less than 10 feet'. How many times was that critical number posted?

A FL couple suffered multiple lightning strikes to a house wall. They installed lightning rods. Then that wall was struck again. If using observation as Fins did, then the FL couple cried, "Woe is me. I will always be a victim." Instead they used reality. That means numbers.

Lightning finds a best connection to earth. Bathroom plumbing struck repeatedly because it connected to more conductive soil. Lightning rods only connected to 8 foot rods in poor conductive sand. Rather than entertain urban myths and wild speculation, the FL couple had their only problem solved. Anyone who understood that previous post knows exactly what they did. An open challenge to each reader: did you read what was posted?

Lightning rods connected to inferior earthing. Therefore did zero protection. They installed more ground rods deeper into more conductive soil. No more lightning strikes - except harmlessly to lightning rods. Where did energy dissipate? Harmlessly in earth. Does a pattern emerge?

Lightning damage is directly traceable to human failure. If anything is damaged, then an informed homeowner upgrades earthing for lightning rods or a 'whole house' protector. What is the most common reason for damage? A human who says "they had a 'whole house' protector and still had damage". The informed say, "they had damage so let's fix what is defective - single point earth ground."

Why must an engineer, who did this stuff even decades ago, repeat concepts understood 100 years ago? Most every reply demonstrated that advertising does brainwashing. Each discussion of damage never once mentions earthing. Why? The concept is not taught in advertisements. Therefore many just cannot comprehend it.

Now some numbers. International design standards over 40 years ago said electronics must withstand 600 (not 300) volts without damage. That was long before the IBM PC existed. Today's standards require computers to withstand thousands of volts without damage. Why do computers remain undamaged when a power strip protector fails? Surges that cannot overwhelm internal appliance protection can easily destroy grossly undersized ($40 and $85) profit centers. Numbers say why a computer survives while a protector fails. Anyone who disagrees must post the appropriate manufacturer spec number. Good luck finding it.

Need we also discuss some resulting house fires? Or was that sentence also ignored?

UL1449 says nothing about protection. UL is about human safety. UL does not care if a protector does protection. UL tests for fire and other human safety threats. In some UL tests, a protector can completely fail. And still be UL listed. Because a protector does not create sparks or fire during UL testing.

Most educated by advertising assume UL (or ANSI/IEEE C62.xx) says a protector will do protection. Total nonsense. UL is only about human safety; not about transistor safety. Transistor safety means direct lightning strikes without appliance damage. UL does not test earth grounds.

More numbers. What does a 300 volt protector do? A 5,000 volt surge is approaching on one or all wires. Current flows in the same direction on all wires. A 300 volt protector, either, leaves 5,000 volts on one wire and connects 4,700 volts on other wires. Or 5,000 volts is on all wires of a protector that does nothing. Either way, that is still 4700 or 5000 volts into an appliance. Why does advertising forget to mention this? Honesty would hurt profits. A $4 power strip with ten cent protector parts selling for $40 or $85.

If one earths a 'whole house' protector, then voltage on any wire anywhere inside the house might be 330 volts. Because all incoming wires were connected short to earth ground - a maybe 330 volt connection. That near zero voltage means near zero energy inside the house. And voltages that cannot harm any appliance.

Informed consumers properly earth a 'whole house' protector. Then a 20,000 amp lightning strike means near zero volts inside the house. So that appliances rated to withstand 600 or a few thousands volts are not damaged.

The IEEE even defines properly earthed 'whole house' protection with numbers. It is not 100%. The IEEE Standard says "99.5% to 99.9% protection".

Phone lines for every North American reader have a superior protector installed for free. Because a 'whole house' protector is so effective, so inexpensive, so easy, and required by codes. How many recommended ineffective protectors without even knowing of that telco 'installed for free' protector? Many, educated by advertising, do not even know of an 'installed for free' protector. But somehow know more?

How many who had damage discussed the earth ground connection? Who is the only person responsible for that earthing? A homeowner who may not even know what earthing is. He then buys a magic box for protection because advertising said so. The informed homeowner inspects his earth ground.

bcf1963 is correct about energy in the entire lightning bolt. But that post only discussed energy onto or inside the house. Completely irrelevant is energy that dissipates in the sky. If a building is properly earthed, then near zero volts means near zero energy dissipates *in* a house. bcf1963 misunderstood the point. Protection is always about where energy dissipates. Near zero volts means energy dissipates elsewhere, outside, and harmlessly. Informed replies can say where energy dissipates - with numbers.

Either lightning connects low impedance (ie 'less than 10 feet') to earth. Or energy dissipates destructively inside appliances. It was always that simple. Protection is always about where "hundreds of thousands of joules" dissipate. Protection is not defined by a protector, disconnecting, a power conditioner, an urban myth, or claims made without numbers. Need I repeat a number that only informed readers remember? 'Less than 10 feet'. If advertising did not mention that number, then it must not be relevant? That is the definition of brainwashing.

What should have been discussed in each reply? Single point earth ground. Why did the FL couple eliminate lightning damage? Instead the naive cry, "Woe is me. I will always be a victim." A protector (or lightning rod) is only as effective as its earth ground - defined with numbers.

It appears that you only saw the words "lightning rods" in my reply and immediately went into some insane meltdown. How about you try reading again, maybe slow down a bit, and see what I actually said.

Westom keeps using that word 'Science". You keep using that word. I do not think it means what you think it means.

If you're going to quote hard numbers you should cite some source for your quantitative analysis.

I always thought the SMP filter in the Furman and Panamax boxes did a pretty good job at shutting down and showing me the unsafe voltage indicator, either over or under in brownout conditions and I noticed improved black level performance on CRTs when I was calibrating.

I would typically avoid MOV based surge protectors as the MOV devices begin to age and no longer clamp when the input voltage exceeds their rated limit.

I quit selling surge protection all together. None of them that claim to cover damage ever pays out a claim, and a couple years ago when the economy first tanked, lightning and home owners policies kept us in business

I read it multiple times. You never discussed anything relevant. Where did you mention earthing even once? Not once implies no grasp how a lightning rod or 'whole house' protector works. Even after your probable mistake was identified, you still never asked to learn.

A FL couple did what any informed homeowner does with lightning rods or 'whole house' protector. Learn from the FL couple. Rather than snipe, they asked questions about why the damage. Only then could the problem be eliminated. Damage from lightning is traceable to human failure. They asked. Then never again had to post, "My experience ... has been less than impressive."

They had direct lightning strikes without damage. You had damage and apparently still do not want to learn.

BTW, protectors that do not claim protection also hype big buck warranties. Warranties that are full of exemptions so as to not be honored. Unfortunately, too many consumers foolishly assume a large warranty means a better product. A large warranty is usually the indication of an inferior product. Read their fine print to learn more.