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Surge Protectors

Message #1 - Posted 2006/05/22 - clw

I was recently told by an "expert" that surge protectors deteriorate over time and the protection is lost.

Is this true? At what interval should one get a new protector? Is it any help to connect two in series (ie, more protection, longer life)?

TIA

Message #2 - Posted 2006/05/22 - Howard S Shubs

Previously, clw wrote:

Is this true?

Yes. Some surge protectors are made to warn you. Others, you can just assume after 2 or 5 or whatever years, are only good as power strips.

Cheap ones contain a part called an MOV, which deals with spikes. Each spike damages the MOV a little, depending on the spike. Eventually, the MOV is useless, as I understand it. In case of a very large spike, these units burn out, protecting your equipment by committing suicide.

If you live some place with very noisy power, you might be well served by getting some kind of power conditioner or UPS, depending on how much you want to spend.

Life is toxic. It leads to death and
too much of it at once can kill you.

Message #3 - Posted 2006/05/22 - clw

Previously, Howard S Shubs wrote:

If you live some place with very noisy power, you might be well served by getting some kind of power conditioner or UPS, depending on how much you want to spend.

What is a "power conditioner or UPS" please? thank you

Message #4 - Posted 2006/05/23 - Bob Harris

Previously, clw wrote:

Previously, Howard S Shubs wrote:

If you live some place with very noisy power, you might be well served by getting some kind of power conditioner or UPS, depending on how much you want to spend.

What is a "power conditioner or UPS" please? thank you

Uninterruptable Power Supply. They provide battery backup for your system.

A power conditioner will regulate the line voltage going into your computer system, removing spikes, and raising the voltage if there is a brown-out (intentional reduced voltage by the power company during heavy power demands in the community). Often comes with a built in UPS as well.

I would go to http://dealmac.com and search for "UPS", then follow some of the links to get an idea of manufactures, features, capacities, and prices available.

Bob Harris

Message #5 - Posted 2006/05/22 - Howard S Shubs

Previously, Bob Harris wrote:

Uninterruptable Power Supply. They provide battery backup for your system.

That's a UPS, yes. You can also get house-sized ones that cover your whole house. Ditto power conditioners for your house.

A power conditioner will regulate the line voltage going into your computer system, removing spikes, and raising the voltage if there is a brown-out (intentional reduced voltage by the power company during heavy power demands in the community). Often comes with a built in UPS as well.

Brownouts are not intentional. They're the reverse of a spike: a voltage sag. What you're describing is a rotating blackout, which is not at all the same thing. Until recently, I worked for the New England equivalent of the California company which directed those, so I do know something about it. Anyway...

Mains power is supposed to "look" like a sine wave. Sags and spikes in the wave can damage equipment, generally in a cumulative way. That is, the more "dirty" power they have to handle, the closer they get to trouble. In a computer, that's generally shown as power supply failure. But I figure that even light bulbs can probably fail due to this.

A power conditioner takes whatever line power it gets, and makes it come out "clean", as a pure sine wave. A UPS generally includes a power conditioner, or at least the better ones do.

So you can go on the spectrum of power from a simple power strip on up to an on-line UPS, depending on your needs and the depth of your pocket. I can go on in more detail if you wish.

Life is toxic. It leads to death and
too much of it at once can kill you.

Message #6 - Posted 2006/05/23 - w_tom

First, five power problems can exist: blackouts, brownouts, noise, surges, and harmonics. Of these, a typical computer grade UPS only addresses blackouts and extreme brownouts. Sags or low voltage are in this category. These are hazardous to motorized appliances and do not harm electronic appliances.

Surges are excessive voltage AND require a different 'system' to make them irrelevant so as to not overwhelm protection already inside that appliance.

Noise is completely irrelevant to all appliances.

Second, power conditioner is a vague term that could apply to any of those above five conditions. Without specific functions and numbers, no one can say which "power conditioning" is being done.

A typical computer grade UPS does not smooth electricity or remove 'dirty' electricity. The typical UPS connects an appliance (computer) directly to AC mains when not in battery backup mode. Where is smoothing or cleaning by that relay? It only exists in myths. Even worse is output by a typical computer grade UPS when in battery backup mode. This UPS output is called a modified sine wave. Its 120 volt output (in battery backup mode) is two 200 volt square waves with up to a 270 volt spike between those square waves. A sine wave output? Of course. Just not a very clean output. And this 200+ volt output is not harmful to computers that are some of the most robust appliances in the house.

If noise causes computer problems, then a human used cost controls to buy an inferior power supply that was dumped into the clone computer market.

A plug-in UPS protects computer data from blackouts and brownouts; for temporary data protection.

Hardware protection from surges - excessive voltage - requires a unit located elsewhere in the building and called a 'whole house' protector.

Third, your original question was about surge protectors wearing out. Yes. And then we can put numbers to it that make that yes irrelevant. An effective protector is typically good for well over a decade because it is properly sized. However since plug-in protectors are not even claimed effective by their manufacturers, then such protectors can even be grossly undersized to smoke. Any protector that smokes is totally undersized and provides no effective protection. Smoke is one way to get the naive to recommend an ineffective and grossly overpriced product.

Meanwhile, those lights can report surge protector as bad, only report a failure due to the protector being grossly undersized. A failure mode that the component part manufacturer's specifications will not define. A failure mode that is unacceptable. The acceptable failure mode for a protector is to degrade. And that light on a protector - it cannot report a degraded protector. That light can only report the protector has failed due to being grossly undersized.

Effective protector for surges and provided by responsible manufacturers is called 'whole house'. Plug-in protectors can even contribute to damage of the adjacent computer. UPS is for data protection from blackouts and brownouts. 'Power conditioner' is a vague expression often used to hype a product on half truths or deception.

Five different power problems are defined. There is no one plug-in solution for all or for even most. The only power conditioner that will address all five is a building wide UPS system such as in telephone switching centers, hospitals, and other high reliability facilities.

clw wrote:

Previously, Howard S Shubs wrote:

If you live some place with very noisy power, you might be well served by getting some kind of power conditioner or UPS, depending on how much you want to spend.

What is a "power conditioner or UPS" please? thank you

Message #7 - Posted 2006/05/23 - Howard S Shubs

Previously, w_tom wrote:

Five different power problems are defined. There is no one plug-in solution for all or for even most. The only power conditioner that will address all five is a building wide UPS system such as in telephone switching centers, hospitals, and other high reliability facilities.

You sure about that? First, a building-sized unit is not "plug-in". It's wired in.

Second, an on-line UPS should produce clean power, since there's no direct connection between the line power and the output power. Comment?

Life is toxic. It leads to death and
too much of it at once can kill you.

Message #8 - Posted 2006/05/23 - w_tom

The OP was not talking about building wide systems. He asked about protectors that deteriorate. He asked about plug-in protectors in series. And he asked about power conditioners or UPS. Yes, a building wide solution can address numerous tasks - at thousands of dollars or more. And yes, a building wide system is not a plug-in device. Nothing said a building wide system was plug-in. However then we include the $thousands necessary for a building wide UPS. Is that an alternative solution to power strips?

A computer grade UPS connects a computer directly to AC mains typically through a relay. I did not say on-line UPS. I said what most everyone has - computer grade. Those UPSes that 'clean' power cost on the order of $500 full retail. Most have a less than $100 UPS that output dirtiest power in battery backup mode AND that otherwise connects computer direct to AC mains. Cleanest power typically comes from AC mains.

A 200 volts square wave - called a modified sine wave - is not harmful to computers. Computers are some of the most robust electronics within a building. That same computer grade UPS can harm some small electric motors - but not harm a computer.

On-line UPSes will only be as clean as the numbers listed in numerical specs. What are THD numbers for each model? Missing numbers are how so many saw '120 volt modified sine wave' and not 200 volt square wave with up to 270 volt spike.

Howard S Shubs wrote:

Previously, w_tom wrote:

Five different power problems are defined. There is no one plug-in solution for all or for even most. The only power conditioner that will address all five is a building wide UPS system such as in telephone switching centers, hospitals, and other high reliability facilities.

You sure about that? First, a building-sized unit is not "plug-in". It's wired in.

Second, an on-line UPS should produce clean power, since there's no direct connection between the line power and the output power. Comment?

Message #9 - Posted 2006/05/23 - Howard S Shubs

Previously, w_tom wrote:

The OP was not talking about building wide systems. He asked about protectors that deteriorate. He asked about plug-in protectors in series.

Correct, and you mentioned "building wide UPS system".

A computer grade UPS connects a computer directly to AC mains typically through a relay. I did not say on-line UPS. I said what most everyone has - computer grade. Those UPSes that 'clean' power cost on the order of $500 full retail. Most have a less than $100 UPS that output dirtiest power in battery backup mode AND that otherwise connects computer direct to AC mains. Cleanest power typically comes from AC mains.

Your definition of "computer-grade" conflicts with how I'd define it, but okay.

A 200 volts square wave - called a modified sine wave - is not harmful to computers. Computers are some of the most robust electronics within a building. That same computer grade UPS can harm some small electric motors - but not harm a computer.

Some are squarish, sure. Others are stepped.

On-line UPSes will only be as clean as the numbers listed in numerical specs. What are THD numbers for each model? Missing numbers are how so many saw '120 volt modified sine wave' and not 200 volt square wave with up to 270 volt spike.

Okay, that's a new one to me. I just looked up the numbers for *my* unit, a Best 610. It says Less than 4% THD at full linear load; less than 7% THD at full non-linear load. What does this mean, please?

Life is toxic. It leads to death and
too much of it at once can kill you.

Message #10 - Posted 2006/05/23 - w_tom

These buzz words - modified sine wave - computer grade - are how color glossies sell inferior products to the naive. Numerical specs are essential. For example, how clean is that UPS output? Is it clean enough to operate small electric motors? 'Modified square wave' suggests OK? Number that many plug-in manufacturers make difficult to obtain - such as THD. Computer grade UPSes will output maybe 20% THD - potentially destructive to small electric motors. Square wave or stepped - its still 'dirty' electricity. A UPS best only for computers: computer grade. If they don't define the term, then naive would assume 'computer grade' as a cleanest output. Myths promoted because numbers are not provided and understood. Clean UPS output would be about 3%. On the oscilloscope, that low THD number would actually look like a sine wave.

Why do bigger name UPSes sell UPSes with such dirty output electricity? They are selling on price which is also why your car battery can survive almost ten years - but a UPS battery typically fails in three.

Sine wave output? Well technically yes. Square wave and stepped wave is a sum sine wave at many frequencies. Those higher frequency sine waves within a square wave are what would stress - potentially damage - a small motor. So they did not lie, did they? 'Sine wave' is to spin half truths on color glossies so that the naive will assume and then promote a myth. 'Computer grade' does not mean cleanest. 'Computer grade' means a dirtiest output.

One factor not well understood is how low AC voltage can be. Computer must power up and work just fine, as even demanded in Intel specs for power supplies. When voltage is so low that incandescent bulbs are at 40% intensity, still, every computer must both startup and work just fine. How often does AC power drop that low? How often do incandescent bulbs glow that dim? Well some cut costs on a clone computer power supply, then require a $100 UPS to fix what should have been inside a $30 more power supply. Many clone computers are assembled using 'cost control' engineering which is why a UPS is then hyped as necessary.

Above is a solution for blackouts and extreme brownouts - made better if UPS informs and shuts down the computer. Noise and harmonics (third and fourth power problem) are made irrelevant by computer's power supply. Computer power supplies already contain any protection effective on its power cord. Protection that assumes destructive transients (fifth power problem) are earthed at building service entrance - a 'whole house' protection system. If not installed, then destructive transients can overwhelm protection already inside the computer.

'Whole house' protectors are so effective and so inexpensive that a telco installs one on every subscriber interface ... for free. Cable TV does not even need a protector - cable must be connected by a wire 'less than 10 feet' to earth ground. Earth ground is the protection. Telco 'whole house' protector is also only as effective as quality of that earthing. The one incoming utility that requires homeowner action (for Mac protection) is AC electric. Homeowner must provide an AC electric 'whole house' protector (from Lowes, Home Depot, or electrical supply houses) AND homeowner's earthing must both meet and exceed post 1990 NEC (National Electrical Code) earthing requirements.

Earthing - service entrance protection - solves this last power problem (surges) so that destrutive transients do not overwhelm protection already inside Macs. Earthing is also what ineffective protectors avoid discussing.

Five power problems and five solutions, from a computer's perspective.

Howard S Shubs wrote:

Previously, ...
Your definition of "computer-grade" conflicts with how I'd define it, but okay.

A 200 volts square wave - called a modified sine wave - ...

Some are squarish, sure. Others are stepped.
...

Okay, that's a new one to me. I just looked up the numbers for *my* unit, a Best 610. It says Less than 4% THD at full linear load; less than 7% THD at full non-linear load. What does this mean, please?

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