DIY surge protection...

That isn't correct. The main function of a surge protector is to shunt the current to ground. In doing so, SOME of the power is converted to heat as it passes through because the MOVs are not perfect conductors and do have some small resistance.

All of the good whole house surge protectors that I have seen have indicator lights that show if they are still functioning or not. Some also have audible alarms to signal that they have failed, or relay contacts that can be sent to a remote alarm system, etc.

Well, we all knew this was coming. Mention surge protector, and like a bolt of lightning from the sky, here comes WTom.

So far, I would mostly agree. Except the part about a direct lightning strike. A direct lightning strike is mostly a red herring, because even if the lightning bolt hit the service cable near the building, it's highly unlikely that the path of all or even most of the lightning is going to be through the service wire and into the surge protector. Far more likely, it will arc with most of the energy finding ground outside the building before it ever gets to the surge protector at the panel or meter.

Here;s where Tom likes to start arguing against strawmans and the rant about plug-in surge protectors begins. The actual question was about a whole house surge protector.

Total nonsense. Every line card on a telco switch has surge protection right on the card where it connects to the incoming line. Much like if you take apart an analog modem, you will almost always find MOVs or similar components there.

In fact, just like the IEEE recommends, the telco uses a tiered approach. Yes, they have surge protection where the line enters the building. But they also have it on the line cards. Months ago I even found you semiconductors designed and marketed for telcos that go on the linecards, complete with the application notes. Yet, here we go again.

Please provide us a link to NIST or any other credible source that says plug-in protectors are ineffective as part of a protection plan. You've been asked that here for years and we have yet to see the link.

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And here comes the list again. What Tom won't tell you is that of those companies on his list of real effective and responsible manufacturers, most of them also sell plug-in surge protectors. They recommend using them as part of a tiered strategy.

As for the HD solution for less than $50, that doesn't square with your criteria of needing a minimum of 50,000 amps, because they have no such product available at HD.

The best advice was already provided. That was the link to the IEEE guide on surge protection.

Everyone can read what respected peer-reviewed engineers recommend. And I can tell you this. They don't say plug-ins are ineffective. Read chapters 5 and 6. Instead, they show them being used as part of a tiered strategy. You put whole house protection at the meter or panel. Then you use plug-ins that route all power and signal through them, to further protect key equipment, eg, TVs, PCs, etc.

Ferrite rings are for EMI, so the buzz in the box stays there and not in your radio or stereo. Switching power supplies can generate a whole lot of hash and that's the type that's gradually replacing the old-syle wall warts. The ring is acting as a choke for RF, also generated by the computer itself. Different deal than surge protection, but also needed these days.

Look up "surgistor" or MOV, that's what's in those surge protectors. They're rated in joules, the amount of energy they can pass. The higher, the better, and more costly they get. The better surge protector strips will say how much energy they can handle on the package. I assume the panel versions do the same. What none of the ad copy says is that MOVs have a distinct lifespan. They WILL wear out after snubbing "x" number of spikes and become useless. Some of the power strip units tie the neon switch light to the MOVs. If no light when switched on, the MOVs have expired and it's time for a new strip. But nobody tells the consumer about it. So there's a whole lot of dead protectors out there that are just power strips now. Usually there's MOVs between ground and each supply wire and between the supply wires. Not rocket science.

As far as lightning protection, they'll do part of that, up to the energy rating. Which is why you need the tiered approach. Arrestors on the line in, surge protectors on the panel and on each high-value electronic item. My sister is always getting hits, they blow the phones off the walls, but since she's gotten decent surge protectors, those get fried instead of the computer or video equipment. They have to be replaced, but she gets the sort with insurance attached, so not that costly.

There are other approaches to surge and spike protection, an MG set is pretty much immune to any such up to direct lightning strikes. A ferro-resonant transformer used to be a big part of the innards of one line of power conditioners, pretty much immune to spikes, but the transformer itself was noisier than a whole switch yard. Had one in a corner of the shop for a mini-computer, had to go outside to talk to anyone. None of those will snub spikes on LAN, phone or video cables, for that you have to go to power strips with built-in protection or stand-alones.

Stan

Looks like a pretty good case for metal enclosed surge protectors.

I posted links to photos of telco cards with rows of MOVs, yet he claims they don't exist. He is just a brain dead troll like Cliff, and The_Mangled_Toad.

Lightning strikes can be far larger than 50,000A (but low percentage). But a strike to a power line has multiple paths to earth. Investigations have shown the largest lightning-caused surge with any reasonable probability of occurring is 10,000A on an incoming power wire. The

50,000A suppressor rating can handle that. High ratings give long life.

The best information on surges and surge protection is in a guide from the IEEE at:

(also posted by Howard and trader) and a simpler guide from the NIST at:

Neither service panel or plug-in suppressors can reliably handle crossed power lines. MOVs which can handle 10,000A for maybe 100 microseconds are rapidly burned out by longer duration events. (These events are probably the major cause of catastrophic MOV failures.)

I would not make my own suppressor attached to power lines (other than fuse protected MOVs in equipment).

Poor w has to warp a thread about service panel suppressors to his favorite topic - plug-in suppressors. Trying to not repeat traders nice reply....

François Martzloff was the surge guru at the NIST and wrote the NIST guide. He also wrote numerous published technical papers. One paper looked at the energy absorbed in a MOV on a branch circuit. It was surprisingly small - 35 Joules max. In 13 of 15 cases it was 1 Joule or less. That was with up to 10,000A coming in on the service wire. There are a couple of reasons for that - I could elaborate if anyone is interested.

Plug-in suppressors are only a "magic box" to w because he refuses to understand how they work - clearly explained in the IEEE guide starting pdf page 40. They work by CLAMPING (limiting) the voltage on all wires (signal and power) to the common ground at the suppressor. Plug-in suppressors do not work primarily by earthing (or absorbing). The guide explains earthing occurs elsewhere.

According to NIST guide, US insurance information indicates equipment most frequently damaged by lightning is computers with a modem connection TVs, VCRs and similar equipment (presumably with cable TV connections). It is likely that much of equipment damage is from high voltages between power and signal wires. This is illustrated in the IEEE guide example starting pdf page 40.

A service panel suppressor can not limit the voltage between power and signal wires. To do that, there has to be a *short* ground wire from the telephone entrance protector to the earthing system near the power service. Also for the cable entrance ground block (and dish....) With a large surge current to earth, the "ground" at the building can rise thousands of volts above "absolute ground". Much of the protection is that power and phone and cable wires rise together. If short ground wires can not be used (as in the IEEE guide example) the guide says "the only effective way of protecting the equipment is to use a multiport [plug-in] protector."

For similar reasons, all protected equipment that is interconnected needs to be connected to the same plug-in suppressor. External connections, like phone, also need to go through the suppressor. Connecting all wiring through the suppressor prevents damaging voltages between power and signal wires.

What does the NIST guide really say about plug-in suppressors? They are "the easiest solution". And "one effective solution is to have the consumer install" a multiport plug-in suppressor.

The required statement of religious belief in earthing. Why aren't airplanes crashing daily when they get hit by lightning (or do they drag an earthing chain)?

Often asked and never answered - simple questions:

- Why do the only 2 examples of protection in the IEEE guide use plug-in suppressors?

- Why does the NIST guide says plug-in suppressors are "the easiest solution"?

- Why does the NIST guide say "One effective solution is to have the consumer install" a multiport plug-in suppressor?

- Why does the IEEE guide say for distant service points "the only effective way of protecting the equipment is to use a multiport [plug-in] protector"?

- Why do your favorite manufacturers make plug-in suppressors?

- Why does favorite manufacturer SquareD say (for their service panel suppressor) "electronic equipment may need additional protection by installing plug-in [suppressors] at the point of use"?

And why can't you find a source that agrees with you that plug-in suppressors are not effective?

For real science read the IEEE and NIST guides . Both say plug-in suppressors are effective.

I have designed EMP protection for missile silos. I have designed lightning protection for aircraft. I have designed surge protection for aircraft.

I have not designed surge protection for households.

But once in a start up, I was testing the upper limit of the input Voltage range for the switching powers supply I had designed for an ultrasound cart. I used a surge protector power strip as an extension chord. I dialed up up the 60Hz AC to a couple hundred VAC.

If the surge protector worked for a while, I don't know. But the stink of the smoke that came out of that surge protector had to be smelled to be believed.

You needed a protector with larger smoke packets. Yours ran out too soon!

Paul

I have a fairly expensive business phone system in my house, central control box and stations here and there. So, I made my own protector. I used a 10 Ohm 1 Watt film resistor in series with each incoming phone wire, and then connected to a 3-terminal gas tube arrestor. The idea is the film resistors blow like ultra-fast fuses during a severe surge, allowing the gas tube to handle what got through before. This has worked well, I've never had any damage to the phone system, but the DSL modems I used to use got blitzed a couple times. The resistors did get popped a couple times, too. I don't think you can get this kind of phone wire arrestor anywhere as a complete unit, except maybe from a telephone physical plant supplier. The gas tubes can be bought from Digi-Key and similar electronics distributors.

I have had some other gear damaged, but due to the nature of the equipment, I am pretty sure it was NOT from anything coming in the power lines. Wires running from one end of your house to the other can develop thousands of Volts when there is a nearby lightning strike, due to magnetic induction. I've had some stuff in my home burglar alarm damaged, as well as an ethernet port on a computer. (Most of this damage all happened in one incident, nearby lightning strike.)

So, I'm not so sure that power line protectors will actually prevent a whole lot of damage.

Jon

The standard protectors are tested against is the so-called 8/20 surge, the 8 means an 8 MICROSECOND rise time. So, the current rises to it's peak value in 8 us, then decays in 20 us after that. Relays take many milliseconds to react, and a lightning surge will just jump right over the open contacts, anyway. So, totally FORGET anything using relays.

Jon

SSR's generally use SCR's, which have the property that they don't turn off until the current is interrupted. Normal 60 Hz power turns off 120 times a second. But, when you tell the thing to turn off during a surge, it will totally ignore the command because the current is still flowing.

Really high-end UPS's do use fancy devices like back-to-back giant IGBT's, but most probably just use an electro-mechanical relay, and are designed to supplement dropped line power, not protect the load. There are "on line" UPS's that only use electromechanical relays to bypass a failed inverter, and otherwise all connection from input to output is through the DC battery bank. These are usually pretty expensive (thousands of $ for a small one) noisy and waste a lot of power, too.

Jon

I remember at work in the early '80's (before PC) getting a whole bunch of modems and a PDP/11-23+ comm board smoked due to a near miss. The modems all turned into maracas. IT said it was induced surge on the phone lines. I saw a lot of lightning arrestor stuff going up on our feeders after that. We were about 5 miles of wire away from our nearest plant power house.

After that, didn't have a problem. Coastal Texas gets a LOT of lightning.

My wife is a big fan of the "Holmes on Homes" show (which is actually pretty good). They go around fixing messes previous contractors have made of house construction/renovation jobs. They regularly install whole house surge arrestors on the breaker panels when they re-wire a place.

We've been thinking of getting one installed, so I did a little research. Leviton seems to be the biggest vendor in the US. They have an interesting dodge, which is a surge arrestor that goes in series with electric meter, inside the metter housing. In my case, this is outside of the house, which means if it turns into a fireball, it probably won't do a lot of damage. I also like the idea of stopping the surge as early in the wiring as possible.

I've got a query in to see if it will fit in just any old meter housing, and how it compares with some of their breaker panel add-ons. Other than having to deal with the electric company to replace the seal on the meter housing, this thing looks like a snap (literally) to install. The cost of the suppressor is about the same for either approach, but the electrician should be able to install the meter version in considerably less than half the time.

Doug White

A friend suffered a 33,000 volt fault to the local distribution. As a result, hundreds of electric meters were blown from their pans. At least 100 clear plastic meter covers in pieces 10 meters from the pan.

Many neighbors suffered damaged electronics and protectors similar to yours. Fortunately, no fires. At least one neighbor had a destroyed 20 amp circuit breaker.

But my friend knows someone who knows this stuff. He only had a 'whole house' protector installed. Therefore he had no damage other than an exploded meter. Even the 'whole house' protector remained functional.

Just another reason why informed consumers earth one 'whole house' protector and do not made money on plug-in protectors. That Belkin does not even claim protection in its numeric specs.

BTW, electric company was not responsible for any damage (as expected). Many electric customers had their meter pans completely replaced due to the explosive power in that 33,000 volt fault.

That is not what I said. I said those are not MOVs. MOVs have excessive capacitance. Telcos use a different device that does not have that excessive capacitance. Please read what was posted. You got caught lying elsewhere. So everything from you is only an attack.

Any protection that might work adjacent to electronics is already inside electronics.

Informed consumers dissipate energy so that surges are not even inside the building.

That Belkin did what plug-in protectors do too often. Threaten human life. Any protector that fails during a surge was ineffective - grossly undersized for that surge. The Leviton and 'whole house' protectors from so many other companies much earth a direct lightning strike - and remain functional.

A direct lightning strike is typically 20,000 amps. Therefore the minimally sized 'whole house' protector is 50,000 amps. 50,000 amps without failure.

The most rare of surges is 100,000 amps. An IEEE paper demonstrates what happens when that 100,000 lightning strike hits the utility power wire. Maybe 40,000 amps attempts to enter the home. (the IEEE picture assumes the 'primary' surge protection system is also properly installed).

Only more responsible companies sell 'whole house' protectors. Not in the list are APC, Tripplite, Belkin, and Monster. Companies that sell protectors for real world protection include Leviton, Square D, General Electric, Intermatic, Keison, and Siemens. An effective Cutler-Hammer solution sells in Lowes and Home Depot for less than $50.

And again, no protector is protection - despite what others have posted. Protection is always about where energy dissipates. Always. Either the protector makes an always required short (ie 'less than 10 foot') connection to earth ground. Or that surge will hunt for earth ground destructively via appliances.

Bud has kindly provided the IEEE citation that shows same. See:

page 42 Figure 8 - the surge energy was permitted inside a building. Since he was only using plug-in protectors, then the surge found earth ground 8,000 volts destructively via the adjacent TV. That is what protectors do. Earth a surge harmlessly outside the building or destructively inside. Page 42 Figure 8 is only what that Belkin can do.

All appliances already contain any protection that will work adjacent to the appliance. Your concern is the rare surge that will overwhelm internal appliance protection (ie my friend's 33,000 volt wire dropping on local distribution). Any potentially destructive surge earthed without entering a building will not go hunting 8000 volts destructively via appliances - page 42 figure 8.

The only thing that makes a protector effective is its earth ground. Therefore any money wasted on plug-in protectors is better spent upgrading earth ground. Protection is always about where energy dissipates - which is why earthing must meet and exceed post 1990 National Electrical code. Which is why informed homeowners upgrade what dissipates energy harmlessly outside the building.

This is true of every protector. Why a 'whole house' protector is so effective and why that Belkin does not even claim effective protection in its specs. This: No earth ground means no effective protection. A protector is only as effective as its earth ground. Protection is always about where that energy dissipates =96 earth ground.

In professional papers, tiering is not about protectors. Tiering is about the only system component that dissipates the energy. Every protection layer is defined by that component ALWAYS required in each protection layer - the single point earth ground. The only item that dissipates that energy. Every protection =91tier=92 is defined only by the earth ground. Any protector without earthing does not =91tiering=92.

A residential 'whole house' protector is discussed. But that entire protection =93layer=94 is defined by what the protector connects to - earth ground. Homeowners should also inspect their 'primary' surge protection system. That is the other protection =93layer=94:

Protectors that do not even claim protection in their numeric specs (ie that Belkin) will not discuss earthing. They hope you =91assume=92 a protector magically makes energy disappear. The NIST (US government research agency) citation provided by Bud is quite blunt about what an effective protector must do:

What happens if the protector does not make that short (ie 'less than

10 foot') connection to earth? That energy must dissipate somewhere? Bud=92s IEEE citation =96 page 42 Figure 8 =96 shows where tha= t energy dissipates: 8000 volts destructively via nearby appliances. Either that energy is earthed. Or that energy will hunt for earth ground inside the building destructively via appliances. Both IEEE and NIST make that point.

I am being kind. I have only called them ineffective. NIST is blunter about what a protector without earthing does:

See those pictures of the Belkin posted elsewhere? It even threatened human life. And the NIST also describes plug-in protectors are >useless ... can be useless if grounding is not done properly.

Only more responsible companies sell effective protectors. With an always required, dedicated wire to make a short connection to earth. Responsible companies including General Electric, Leviton, Intermatic, Siemens, Square D, and even the Cutler-Hammer solution that sells in Lowes and Home Depot for less than $50. In every case, an effective protector has a wire to dissipate energy harmlessly into earth. Plug- in protectors do not =96 are not part of a =91tiered=92 solution. Without earthing (ie plug-in protectors), "The best surge protection in the world can be useless if grounding is not done properly." Could they be any blunter? Protection is always about where energy dissipates. Each protection layer is defined by what provides protection =96 the single point earth ground.

Secondary protection is earthing at the service entrance. Primary protection is earthing by the utility. Each protection layer is about where energy dissipates =96 not by some high profit box that somehow makes energy magically disappear.

You don't have to be so sure. The IEEE and NIST are though.

Another factor, many of the surge protectors intended for panel use have indicator lights that show the status. Some even have audible alarms to indicate that the protection has taken a hit and is no longer functioning. If it's buried in the meter housing, you have no way of knowing if it is still functioning.