Surge Protector recommendations - Page 24

Over the years, Martzloff has changed his opinion from cascading good to cascading bad, I believe he now thinks good..

His primary "bad" thinking was because of the possibility of having a gas discharge tube at the service entrance cascaded with an MOV... Under these conditions, the MOV would prevent the tube from ionizing ever..until the MOV fails short and it's breaker clears the line. Unfortunately, breakers do still take some time to clear magnetically, the MOV must not lose containment before the clearing.

Running the end of branch (EOB) 30 feet or so from the panel spd guarantees the EOB does most of the work, but when the line current IR drop exceeds 100 volts or so, the main panel clamps that current. Essentially, the cascade guarantees an exceptionally low current peak at the EOB. So, the EOB is seeing peaks of 100's of amps levels, which is trivial, and the service panel unit rarely clamps. Best of both worlds.


It gives a higher MTBF to the overall system, but requires more robust EOB equipment. It also gives one point of failure for excessive conditions.

Back in '81, the semi manufacturers (myself in that bunch) were using 800 volts as a target for line operation silicon. Since then, it may have gone up.


Typical SMPS units have a diode or bridge directly connected to the line. If that silicon's BVR is exceeded, it is toast. The robustness of a 90 mil diameter silicon chip to avalanch reverse breakdown current is not high at all. For example, a kilojoule BVR dissipation at 1000 volts will destroy most 3 ampere diodes. 1000 volt diodes are not that expensive anymore.


Earlier triacs were certainly less robust, but yes, they do not like fast transients at all. In general, a silicon device will not avalanche across it's bulk where it would absorb lots of energy, but in a very small localized area at the edge of the device where the energy is concentrated. Even if it doesn't avalanche, the dv/dt is capable of turning on a small part of the triac, which can also destroy the device..

Agreed. But also make sure that the EOB device is multiport.

Cheers, John

Good point. I was wondering what the down side of series mode devices are, besides cost and the fact that they are limited to 20A or so. Now that I think about it, it seems that if you want protection from induced surges from nearby strikes that would rule out series mode devices like SurgeX because you need protection for all the ports (antenna, cable, satellite, ethernet, etc.) at the device. All the series mode devices seem to rely on protection of these cables where they enter the building. If you live somewhere like I do, induced surges from lightning isn't a significant threat. But if you live somewhere nearby strikes are a significant threat, it seems that a series mode device may not be the best way to go.

The point of most of this thread is that mov devices are best at the service entrance or breaker box and Series Mode is best at downstream plug-in devices.

Nonsense. It is just the point of series mode aficionados like you. Unlike you, I have no bias either way. I just want effective protection at the best price. I will buy what is appropriate. Yes, series mode devices do not induce surges on the equipment grounding conductor, and apparently can achieve lower let through voltages (we'll see for sure when the UL 1449 3rd Ed. numbers are available). There may be applications where series mode devices provide an advantage. But I have yet to seen convincing evidence in this thread of the necessity of using series mode devices point-of-use devices over MOV-based point-of-use devices in the typical AV system assuming the later are used appropriately (e.g. multi-port devices for connected equipment) and considering the inherent ability of most devices to withstand moderate surges. For that matter, I have yet to see convincing evidence of the need for point-of-use devices of either technology if you have a decent whole-house system and the usual distribution of loads on the various branch circuits, at least where I am located.

As to the single line of my previous post you quoted out of context, you obviously just don't get it. What can I say? There are scenarios where a series mode device like the current SurgeX devices will provide inferior protection to a multi-port MOV based device simply because it only protects the AC port. Whether this is important or not depends on your environment. Where I am located, it is not an issue if I have a whole-house system.

Let me use an analogy. A Lamborgini by most measures is a better car than a Fiat. Both will get me to work. If all I need is a way to get to work is a Fiat, why should I buy a Lamborghini? Likewise, assume that series mode protection is superior to MOV-based protection, and both will give me adequate protection if used appropriately, why should I buy series mode protection?

I have several Furmans and a SurgeX flatpack. All very good surge protectors. I'm thinking of purchasing a Furman or SurgeX UPS for my front projector. Their UPSs do everything from battery back up, trim/boost, very robust surge protection, and high quality emi/rfi filtering all in one package. Its tough to decide between the two brands.

Posts deleted. One of them was long and had several good points but if you can't state your position without the insults it's going to get deleted as I don't have the time to go through and edit them out line by line. Again, please state your position and refrain from personal insults.

Sorry about that, that was my post.

Colm, some suggestions for you, you need to back up your claims for once with evidence and numbers with your own test results on the advantages and disadvantages of MOV's versus Series Mode for downstream plug-in protection because you and a couple others have made many claims without backing them up with actual evidence.

You and a few others have had years as a member of this website to purchase a MOV device (APC/Monster/Panamax/Triplite) style unit and a SurgeX and compare them and do your own experiments and come back here with the results and share them with us, but instead you demand we do all the work and give you all these inside info secret memo's from deep inside the company's vault that we don't have access to. Time for you and the other skeptics to start doing your own fair share of tests and back up your claims and put to rest any suspicions.

More nonsense.

I have said I assume that series mode devices do everything thing that they claim. The only disadvantages for series mode devices I have mentioned are the cost, the fact that they are only available for 20As or less, and that they don't protect against surges originating on ports other than the AC, which could be a problem under very specific circumstances. The only advantage for MOV based devices I have mentioned is cost. And if MOV based devices can do an adequate job at a lower price, then that is the best solution IMHO.

I only have two questions about series mode technology that concern the two primary advantages claimed for series mode devices.

Why do I need zero, or even close to zero, let through voltage if most devices are inherently protected to 600-800V? My source for those numbers is one of Martzloff's papers on the NIST site. You can find it easily if you care to. It is easy to vet his credentials, too, if you care.

Why do I need a device that does not shunt surges to the equipment grounding conductor if I use a multi-port MOV based device that protects my equipment from the surge generated on the equipment grounding conductor? Martzloff recommends using multi-port devices, which he calls surge reference equalizers, for this purpose in another one of his papers on the NIST site. You can find that one easily, too, if you care to.

I have done my research. It seems to me that you would be well served to do the same instead of relying on statements from salesmen.

As for demanding test results to prove claims, I could ask the same of you. But my questions aren't about which technology provides the lowest let through voltage.

I will repeat my question. Assume series mode is everything it is claimed to be. Why should I use it if MOV based devices properly used will do the job for less money?

Now you are just being ridiculous. I never did any such thing.

Both seem to have a reputation among their users for good quality. All else being the same, I would go with the least expensive option that gives you what you want. Wasn't there some claim by SurgeX that Furman products weren't really series mode at one point? How did that come out?

Anybody know why 330V was chosen as the minimum rating for SVR under UL 1449 2nd Ed. and the VPR under UL 1499 3rd Ed.?

Why don't you prove mov's are equal at protecting against surges through the AV as Series Mode is? Buy a mov based device and a Series Mode devise and send any surge of your choose through the machine, come back with to us with the results.

Asked and answered. Would you please stop repeating yourself?

Asked and answered. Will you please stop repeating yourself?

Not a reasonable request, one largely has to rely on others research in this area. I also doubt he's going to be crash testing cars before he buys one .

No, but I have crashed tested them after buying...

Two users now banned from thread. Carry on.

So, anybody know why 330V was chosen as the minimum rating for SVR under UL 1449 2nd Ed. and the VPR under UL 1499 3rd Ed.?

A member here recently spoke to a Furman engineer about that same question. The engineer stated that many Furman models do have a series mode. But, have MOVs before and after the series mode. He stated the MOVs are very robust and almost never go even after several nasty surges.

I have a hunch that 330 is the expected - or listed - rating at which most devices will fail, without any additional 'protection'.

Quick search fail.

Lots of heated forum discussion about surges, everywhere - many different forums. Electrical, computer, engineering, many more.

David Haddad, sorry to annoy you.

Found this bit on voltage tolerances

http://community.myelectrical.com/wi...tolerance.aspx

I think most currently available AC-DC convertors incorporated into electronics accomodate a very wide range of inputs.

The standard converters cover at least 80 volts for 120 sag, and 240 for high level, allowing operation in many countries without a transformer.

Very nice link. Parallel type MOV protection absolutely cannot be allowed to conduct a 120% line level that lasts half a second, that would exceed it's surviveability if it clamped such line input. So 204 volts the bare minimum MOV to meet the 120%.

I found a 208 page anthology written in 2002 by Hahn and Martzloff, first published in IEEE 31 CP 67-430. It is an accumulation of papers from 1976 to 2002.

The last article discusses the cascade coordination between a 130 volt MOV at end of branch with a 150 volt MOV at the service panel. Rather odd numbers for 120 volt RMS circuits, as peak is 170 volts. I suspect that they are actually discussing MOV's with that voltage as the let through. That would make them 300 volt units and 320 volt units. Not 330 as per 1449. But what really peaked my interest is the cascade coordination tables they presented which showed the energy dissipation tradeoff between the 150 panel mount and the end of branch 130 volt unit. They modelled .1 meter, 1 meter, and 10 meter lengths of wire between the panel and the end of branch. I suspect that the 10 meter number is what was carried into NEC.

Of interest is the 1991 article by Martzloff..""diverting surges to ground: Expectations vs reality.
Reprinted from Proceedings, Open Forum on Surge Protection Application, NISTIR-4654, August 1991


The opening statment::

""A misconception is sometimes encountered, that surges can be eliminated by sending them on a one-way trip to "ground" in a manner similar to leftovers that disappear in the kitchen sink disposall, never to be seen again. Unfortunately, electricity travels along closed loops, and no special SPD configuration nor amount of "grounding"– be-it ‘dedicated’, ‘isolated’, ‘separated’, ‘delayed’, or otherwise – can dispose of unwanted electrons.""

Cheers, John

Interestingly, Mr. Martzloff offers his IEEE email address on his website, 'For Questions'.

I found this quote from Martzloff from 1995, a draft of an un-published 'working document':


http://www.eeel.nist.gov/817/pubs/sp...es/Enduser.pdf

This doc is linked from Martzloff's website 'Anthology'.

Great research.

Now that I think about it, it should have been obvious to me. A MOV with a 130V maximum continuous voltage rating has a maximum clamping voltage right around 330V, some a little less, some a little more. UL 1449 and the corresponding IEEE standards are MOV-centric. The minimum rating of 330V has nothing to do with what equipment can withstand, just the lowest practical value achievable using MOVs.

Yes, the earth ground doesn't magically make the surge go away. But a low impedance ground is still needed for an effective return path. The surge is going to find the easiest way home.

It seems that surge protection is a very poorly understood field, even among EEs, and full of hype from manufacturers trying to sell you something. Martzloff spent nearly his entire professional life researching it, and still doesn't have all the answers. IEEE says they don't have all the answers either in their standards. I am all for a spirited discussion of the topic, including all the technologies. What I don't like is aficionados of one technology or the other who attempt to squelch that discussion.

I think I understand MOV based devices reasonably well. I would like to know more about series mode technology. But it is kind of hard to wade through all the BS. Some folks say nothing else will do, and others say it is only a glorified noise filter. There seems to be no useful, independent information on it, just what the manufacturers tout and the opinions of aficionados of one technology or the other. The situation isn't helped any by the fact that there are different approaches to series mode protection, and approaches that combine series mode and MOVs.

I was looking at pictures of the insides of a couple of series mode devices, one SurgeX and one Furman. One thing that I noticed is that they contain electrolytic capacitors. Electrolytics are used primarily to get a large capacitance in a small space, or at low cost. The former is likely the driving factor for series mode devices. The downside of electrolytics is that they degrade over time. The capacitance changes and the ESR increases. In other words, they have a limited useful lifetime, just like MOVs. They can also fail catastrophically, just like MOVs. But neither is a big deal, MOVs or capacitors, properly selected and applied, will last a long time, say a decade or more, just not forever.

As a MOV degrades the clamping voltage goes down, in effect giving "better" protection until the clamping voltage gets so low that the MOV is conducting too much and either fails or is taken out of the circuit by a fuse or breaker. What happens in a series more device as the electrolytic capacitor degrades?

I hope I dont banned from this thread for asking dumb questions but I cant seem to understand how things work....Browsing through the audiogon page, I came across this: http://www.mitcables.com/available-i...lex-super.html My question is, I already have my gear connected to a panamax power conditioner, will adding something like this benefit at all or improve my system or will it basically be a waste of time/money?

Asking basic questions won't get you banned from this thread or any other. That device appears to be a single mode (L-N) MOV based surge protective device combined with a line filter. I don't think it will be of benefit to you if you already have a Panamax power conditioner. You should already have equivalent or better functionality in it.

FWIW this is a surge protection thread. You might get more useful feedback in a power conditioning thread.

Thank you for the explanation

Did they get an EE on staff?


'Series Mode' is a Trademark property of SurgeX and was approved by the U.S. PTO by way of our industry related documentation and patents that it: "Provides an inductor system as the first means of protection." IEEE C62.41 was the primary guideline for the further development of the Harford-Benton-McCook patents relating to SurgeX products.


A branch circuit SPD using an MOV in front of, in back of or sideways of, a small ferrite core series inductor, labeled as 'series something', is in my opinion, a marketing persuasion by our competitors intended to ride on our back and confuse you, and the only way to promote a product 'looking like ours' without violating our patents. Are you a Switch or a Filter?


An MOV is a semiconductor switch. Switches will wear out and can suddenly fail when stressed. The monitoring of these switching devices over time as 'functional' is tedious and a guessing game at best. A filter properly designed for its application will not wear out and will only fail if misapplied. Think about your passive LC subwoofer crossovers...when will it wear out?...perhaps when you wire it up to 440V just for fun?...or when you listen to too much music?

I can hear Colm talking about electrolytics now... :-)


By the way, John is my brother...say Hi to Mom for me Bro ;-)


Cheers,

Michael McCook
SurgeX International
Office: (+1)610-847-4956
Direct: (+1)267-251-6119
Fax: (+1)610-847-4955
Michael@SurgeXInternational.com
Skype: michael.mccook
www.SurgeXInternational.com

What happens in a series more device as the electrolytic capacitor degrades?[/quote]

Since the electrolytics in our circuits float at the peak of the power wave and they are behind our inductor syatem, they don't get stressed like electrolytics utilized in power supplies, etc. We use high grade caps and the lifetime is basically the 'shelf life'. Since SurgeX has 'zero' let-through when new, you might have a very slight increase 20 years from now which is of no consequence to the integrity of the device.

My Harman Kardon Citation Eighteen system shows no sign of wrinkles or dry skin after 30 years....and it's used for BGM in the house every day. Of course it's plugged into a SurgeX.