Actually, it goes to ground. The speed of grounding depends on the quality of the ground, but that's where it ends up. (I know, I'm going to hear about "less than 10 feet" ground connections). Agreed. The lower the impedance of the ground, the better off you are, but it's not the absolute I get from reading your postings.
What you do accomplish by clamping all the wires together is limit the surge current within the protected device itself. If all wires are at (roughly) the same potential, there will be reduced opportunity for damaging current flows.
Can a plug-in surge protector provide absolute protection against all surges? Hell, no. Is it better than nothing? Hell, yes.
Nothing was absolute. These posts discuss a 'daily tabloid' version. Conductivity of earth ground cannot be made sufficiently low. So we also earth (single point earth ground) to create equipotential. If major currents are conducted below the building (rather than inside a building), then increased voltages beneath that building are equalized. Even less currents obtain earth destructively via appliances when using better earthing techniques such as Ufer ground or halo ground. Both conductivity and equipotential is required because neither can be sufficient.
If not yet obvious, all appliances contain internal protection. Surge energy that (mostly) gets earthed means protection inside all appliances is not overwhelmed.
I repeat what the IEEE guide says. Repeating again: "The guide explains earthing occurs elsewhere. (Read the guide starting pdf page 40)" .
. Another total invention. Must be the drugs.
Still missing - a source that agrees with w_ that plug-in suppressors do NOT work.
Still missing - answers to embarrassing 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 IEEE guide say (for long phone entrance ground) "the only effective way of protecting the equipment is to use a multiport [plug-in] protector"? Why don?t you ever answer questions w_?
For real science read the IEEE and NIST guides. Both say plug-in suppressors are effective.
Guide says that if the earthing (and 'whole house' protector) does not do that earthing elsewhere, then the plug-in protector can earth a surge even 8000 volts destructively through an adjacent TV - Page 42 Figure 8. Earthing must be done elsewhere - either by a 'whole house' protector or by a direct (hardwire) connection to earth.
Every source says a protector is only as effective as its earth ground. A protector not intended for (does not even claim in numeric specs to protect from) the typically destructive surge - that protector may then earth that surge 8000 volts through the adjacent TV. Even Bud's citations demonstrate that reality.
Why does the telco install one 'whole house' protector on every subscriber line? Why does the telco install same protectors on every wire where every cable enters their building? Why does the telco not use plug-in protectors? An effective protector makes a short connection to earth ground as every source (including those from Bud) state. A protector is only as effective as its earth ground. A protector without earthing will clamp that surge energy to what? Maybe into the adjacent appliance - Page 42 Figure 8. That surge must find earth ground as Bud's NIST citation says. A plug-in protector simply gives surges more paths to find earth ground - destructively. Bud's citations demonstrate why the easiest solution can even contribute to appliance damage.
Of course Bud will reply with these same accusations again. Obscene profits on a $3 power strip with some ten cent parts selling for $25 or $150. These profits are at risk should you learn why a protector is only as effective as its earth ground.
Telco only installs 'whole house' type protectors both in their facilities and where their wire connects to subscriber homes. Why? Telco installs effective protectors - not scams promoted by Bud.
. The IEEE guide clearly explains plug-in suppressors work primarily by clamping, not earthing. It takes willful stupidity not to understand.
Still never seen - a source that agrees with w_ that plug-in suppressors do NOT work.
Still never seen - answers to embarrassing 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 IEEE guide say (for long phone entrance ground) "the only effective way of protecting the equipment is to use a multiport [plug-in] protector"? Why don?t you ever answer questions w_?
For real science read the IEEE and NIST guides. Both say plug-in suppressors are effective.
Are you saying that a $15 or $20 surge-surpressor (rectangular box with 5 or 6 sockets in it) is (often) *higher* rated than what comes with a $300 UPS?
. The protection provided by a UPS is for power loss to allow orderly shutdown. The kind of UPS commonly used does not intrinsically provide surge protection. But surge protection, the same as in plug-in suppressors, is commonly added.
I recently bought a major brand plug-in suppressor with ratings of 590J and 30,000A per MOV, 1770J and 90,000A total for under $30. I don?t have a UPS and have not looked closely at them, but what I have seen is relatively low surge amp/Joule ratings. My personal preference would be to plug a UPS with low or no ratings into a plug-in suppressor with high ratings. I may go for excessively high ratings, but high ratings mean the suppressor is very unlikely to ever fail. They also often have a protected equipment warrantee.
What little looking at UPSs I have done I also didn't see a UL1449 listing.
Perhaps most important is, as I wrote above, all wires going to a set of interconnected equipment must go through the suppressor.
You need to look a little closer before making judgement calls. UPS equip is available with some very impressive ratings in the general market. Take a look at the specs of some of the major manufacturers; I mean actually look at them, not just glance at the Home Pages.
Careful: Some UPS's specifically state NOT to plug them into power strips, not just because the power strip might be turned off, but more importantly, what you call "high ratings" plugged into another "high ratings" product could cause ringing, an oscillatory effect that would rise in magnitude due to resonances, until something broke, usually with smoke. "High ratings" are obviously beneficial, but not when they're impratically assembled in opposition to the manufacturing instructions. A UPS is a lot more than just a set of components to protect against surges. In addition, the joules that a UPS can tolerate are inherently high because there is a battery and/or a transformer between the line and the regulated output that in itself allows the spiking without damage. It's when there are unregulated outputs also provided that the "high ratings" actually have much value with a UPS. As a result, their specs are a little harder to understand. Most however are happy to answer questions if one asks. Have you asked?
Just try to find a verifiable case of the warrantee ever paying off to a non-corporate user. It's hype and that's about all it is. I tried to take advantage of the warrany once; and gave up after four rounds of crap; it quickly reaches a point of diminishing returns for most people in pursuing it.
Then you're either myopic, purposely not looking, or are looking in non North American Markets. Since you say "UL" then I assume you mean the U.S. market. It is illegal to sell any such product in the US without those ratings, and some states like Ca. even have their own added requirements above and beyond those. UL & CSA markings are required in NA, and acceptable substitutes (actually more onerous specs) are ETL and any EU safety marking. Most are marked with so many safety markings you actually have to look to see if a particular one if there or if it's there by MUA.
Your credibility is in serious question; please refrain from such future responses as you are obviously ill equipped to do so.
. A couple times in the past I have looked. I looked again with the following results:
Belkin F6H375 and F6H550-USB 700J IEC standards only
F6C550-AVR 890 Joules I did not see Joule ratings for F6C750-AVR, F6B750-AVR, F6C900-UNV for this set the safety standards were IEEE C62.41 Category A and UL - not specific for which standard is covered
APC BE350R 365J "meets UL 1449", UL 1778, UL 497A, UL 498 BE750G 365J "meets UL 1449", UL 1778 BP500CLR 420J "meets UL 1449", UL 1778 BP700UC 510J "meets UL 1449", UL 1778 BR1300LCD 340J "meets UL 1449", NOM, TUV
Joule ratings ------------------------------------ I would not call anything under 500J "high". That leaves 2 Belkins and 1 APC. None were as high as the 1770J plug-in suppressor I bought. A number of the Belkin units did not have a Joule (or surge amp) rating. (IMHO manufacturers used to provide much better specs.)
Safety certifications --------------------------- UL497A is telephone protector UL498 is plugs & receptacles UL1778 is UPSs UL1449 is surge suppressors IEEE C62.41 - standards for surge testing but would be, at best, "self certification" IEC - European certifications have no validity in the US TUV may be recognized as a testing laboratory but no indication of what tests it performed
"meets 1449" to me means the manufacturer is claiming the UPS will pass UL1449. That is not the same as "listed under UL1449" which means the device has been tested by UL, with on site followup.
IMHO none of these UPSs is "listed under UL1449". None of the UPSs I have looked at in stores has had a UL1449 listing. The closest was "meets UL1449".
Better ratings may certainly be available. It would be nice if manufacturers made it easy to find them. These are UPSs that would likely be used in a home. .
. In rather extensive reading I have never heard of ringing or resonance in suppressors.
You really don?t want suppression in 2 connected plug-in suppressors. You have little idea which suppressor will actually clamp at a lower voltage. And if equipment is plugged into both and the UPS is doing the actual clamping, there will be a voltage drop between the plug-in and UPS. That will appear as a voltage between equipment plugged into both. .
I was careful to say "a UPS with low or no rating". .
. I also carefully said "the kind of UPS commonly used", which connects the protected equipment to the incoming line until there is a problem. Full time conversion UPSs are certainly available, but not likely to be used by a home user (or most offices). .
. The question is irrelevant because what I said excluded full time conversion UPSs. (And they are not likely to be used in a home.) .
. Never had to try to claim damage. Manufacturers are reasonable to want a solid basis that equipment was not protected. People may think damage was from a "surge" when it is not. Then there is fraud. Would seem like companies would get a bad rating with the Better Business Bureau if they did not pay off valid claims. .
.
I am specifically talking about the US.
I know of no requirement that only "listed" equipment be sold.
Some "nationally recognized testing laboratories" (ETL) are likely allowed in most jurisdictions. "EU" is not one of them. The only detail I have read is for OSHA: NRTLs test to established standards, most of them from UL. A NRTL has to be qualified to test under specific standards.
Myopic? None of the UPSs I looked at above was "UL listed". .
. You appear to be ill equipped to read what I actually wrote. And perhaps you could show "UL listed" UPSs are commonly available.
While reading wikipedia's discussion on MOVs, well, where does that surge energy get dissipated? That is what MOVs (like zener diodes, gas discharge tubes, etc) do. None protect by absorbing surge energy. If so, then all would explode. Each works by - as NIST says
-
From a 1 Jan 2007 discussion entitled "Acceptable Lightning Ground?" in rec.radio.amateur.antenna :
"Planning guide for Sun Server room" from Sun Microsystems:
Surge energy must be diverted to where energy gets dissipated harmlessly. Some will confuse energy 'absorbed' by an MOV as the protection. However as MOV joules increase, then energy absorbed by that MOV decreases. That's what we want. More energy diverted into earth. Less energy absorbed by the protector. A protector does not provide protection. What absorbs (dissipates) a surge provides protection - earth ground.
Protection is about dissipating surge energy without damage. A short connection to earth. Diverting surge energy is what avalanche (zener) diodes, MOVs, and GDTs do, as even the Wikipedia source would note.
Furthermore, it is not just any earth ground. All incoming utilities must connect 'short' to the same "single point earth ground". How to correct an installation mistake is demonstrated by a utility:
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industry professional demonstrates that every incoming utility (including underground) wire must be earthed (directly or via a protector) in "The Need for Coordinated Protection"
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MOVs that diverts a surge must be sufficiently large so as to not fail catastrophically or trip that failure indicator light. MOVs must be sized so that even a direct lightning strike is earthed and MOVs remain functional. As many have observed, plug-in protectors manufactured for profit rather than protection have a history of failure indicated by that lamp. That lamp says protector circuits were grossly undersized - was ineffective proetction.
UL1449 means a surge protector circuit should not kill humans. To achieve a UL1449 approval, a protector circuit can even completely fail during testing - provide no protection - and still be UL1449 approved. UL makes no effort to claim surge protectors work. UL's concern is human safety. UL1449 does not mean a protector provides protection.
A UPS that does not have surge protection circuits obviously would not require UL1449 approval. Others automatically assume UPSes provide surge protection rather than first review numeric specs. UL1449 says a surge protection surge was tested to not burn down the house. UL1449 says the protector did not threaten human life when tested using C62.41 testing waveforms. However some electrical events may still create safety risks in some UL approved protectors (manufactured for profits rather than protection):
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If it contains surge protector circuits, then it would have UL1449 that says those circuits should not threaten human life.
. There are multiple tests to pass UL1449. One of the early ones is a series of 20 surges. The suppressor can not fail during that test.
The suppressor can fail later. For example when subjected to long overvoltage a suppressor can fail safely. (MOVs are good at very high currents for very short duration (surge) but not long duration.)
Contrary to w_'s delusions, UL1449 includes tests to assure suppressors (both plug-in and service panel) have protection functionality. .
w_ can't understand his own hanford link. It is about "some older model" power strips and says overheating was fixed with a revision to UL1449 that required thermal disconnects. That was 1998. There is no reason to believe, from any of these links, that there is a problem with suppressors produced under the UL standard that has been in effect since
1998. No link even says any failed suppressor was UL listed.
Still never seen - a source that agrees with w_ that plug-in suppressors do NOT work.
Still never seen - answers to embarrassing 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 IEEE guide say (for long phone entrance ground) "the only effective way of protecting the equipment is to use a multiport [plug-in] protector"?
A protector must remain functional during preliminary testing so that the relevant test can occur. Relevant test is a real surge =96 the test that might expose a human threat. During =91real surge=92 testing, a grossly undersized protector can completely fail - provide no protection =96 and still be UL1449 approved.
Whether a protector provides protection is irrelevant. Bud hopes that facts gets forgotten to imply UL1449 means surge protection. UL1449 only implies a surge protector circuit exist. It says nothing about protection. UL1449 approval need not exist if protector circuits (that can create fires) do not exist.
Scary pictures are a problem with protectors that even meet UL1449 standards. Protector with UL1449 approval, sold to maximize profits, need not provide protection. It can completely fail =96 provide no protection =96 as long as it does not spit flames during ANSI C62.41 test waveforms.
Bud refuses to answers the only relevant question. WHERE DOES A PLUG-IN PROTECTOR CLAIM PROTECTION IN NUMERIC SPECS? Bud cannot answer because no plug-in protector claims protection from typically destructive surges. Bud discusses UL1449 hoping you assume UL1449 says protection exists; hoping you ignore fire risks. Protector can completely fail even during UL1449 testing and still be approved. Any appliance without protector circuits does not need UL1449 approval.
Wow, the amount of misinformation and misapplied information here is amazing and all the apples and oranges compaisons make it even more so.
A direct lightning strike can not be "earthed" for the expected duration of most lightning strikes. No component yet known to man will withstand a direct lightning strike. Protection is not sold to protect agains direct lightning strikes - ever. Don't let the advertising hype and phoney warranties fool you.
There is a lot more to surge protection than the path to earth. In fact, most often the actual path to earth is irrelevant: What IS relevant is the path of the surge AROUND the equipment being protected; the protection components are by definition sacrificial and there is no way around it.. Earth protection is going to do nothing for a surge that sends the hot line thousands of volts in one direction and the neutral likewise in the other direction. Neutral is NOT earth to surges of the magnitudes discussed here. Whole House protection is indeed worthwhile, and a good idea, but ... it does not for instance mean that you don't still need protection for your computer. There are plenty of surges and spikes generated IN your home every time a motor starts, changes speeds, or a relay throws, a switch is activated, and on and on. They can be very substantial. That, on top of the spikes and surges that make it through the power xfmr is why even with whole house protection, one should still have protection on their more expensive components; computers, electronic sewing machines, refrigerators, microwaves, etc. etc.. Microwaves in fact are another substantial source of spikes when that klystron kicks on and off, just as are many makes of laser printers. And etc.. Besides, a UPS is still much better; it's fast, disconnects the mains, and lets the computer or whatever it's protecting be powered down gracefully in any situation from a brownout to loss of grid.
Get real, people; either quite guessing and surmising or get off the topic. I think I only saw two people in this thread seemed to actually know what they were talking about. The rest of it's crap of the highest quality as crap goes.
That's good, except: A UPS certainly does still need UL1449 or an equivalent rating/testing/certification/registration/qualification. In fact, in Ca, the state adds its own safety specs, especially Orange County. It is illegal to sell a UPS without safety complaince in the US and Canada, whether it's UL, CSA, MUA, ECL, ET, CT or whatever.
. Comments do not involve a direct lightning strike to a house. For that protection you need lightning rods.
Francois Martzloff was the surge guru at the NIST. He wrote numerous published technical papers on surges an surge protection. He is an expert in the field.
------------------------- One of Martzloff?s papers looked at a 100,000A lightning strike to a utility pole behind a house in typical urban distribution. It is calculated that on average a worse event would happen once in 8,000 years (more often in central Florida, less often in Nevada).
Of the 100,000A, 30,000A went toward the house on the neutral. The energy on the neutral was directly earthed by the N/G/earth-electrode bond required in US services. Some of the energy is inductively and capacitively coupled to the hot service wires. I believe Martzloff?s paper is the basis for the (IEEE standard) maximum likely surge on hot power lines of 10,000A
Service panel suppressors with ratings over 10,000A are readily available.
Martzloff?s paper should still be available on the internet if you want to read it.
------------------------ Another Martzloff technical paper looked at a MOV at the end of 30 ft and longer branch circuits with 2,000-10,000A surges and no suppressor in the service panel. (Compare 10,000A with the max likely 10,000A above.) The maximum energy dissipated in the MOV was 35 Joules. In 13 of
15 cases it was 1 Joule or less.
It should be noted that neither service panel or plug-in suppressors protect by absorbing energy, but they absorb some energy in the process of protecting.
One of the reasons energy at the MOV is so low is that at about 6,000V there is arc-over (US) from hot bus to panel/neutral/system-ground/earthing-electrode. After the arc starts the voltage falls to hundreds of volts across the arc. That dumps most of the surge energy to earth.
Maximum Joule dissipation was for the short branch circuit and surprisingly the lower current surges below 5,000A. The reason is that the MOV was able to clamp the voltage at the panel and hold the voltage below 6,000V required for arc-over. Receptacles also arc-over at about
6,000V
As I wrote elsewhere, I recently bought a major brand plug-in suppressor with ratings of 590J and 30,000A per MOV, 1770J and 90,000A. Compare to
35J on a severe surge.
Martzloff?s paper should still be available on the internet if you want to read it.
---------------------------- Martzloff has also written "In fact, the major cause of [surge suppressor] failures is a temporary overvoltage, rather than an unusually large surge."
Source should still be available if you want to read it.
----------------------------- The NIST guide, written by Martzloff and referenced elsewhere, cites US insurance information that says the most commonly damaged equipment is computers (with modem) and TV (presumably with cable). All can be damaged by high voltage between power and signal wires. The IEEE (starting pdf page 40) guide has an illustration of a surge coming in on a cable service resulting in 8,000V between power and cable wires. The guide also shows using a plug-in suppressor to protect the TV.
All interconnected equipment has to be connected to the same plug?in suppressor and external wires, like phone and cable, have to go through the suppressor.
---------------------------- From Martzloff?s research (and other sources) I see no reason why a properly connected service panel suppressor or plug-in suppressor can?t protect against about any lightning surge.
I eagerly await your sources that say service panel and plug-in suppressors can not protect against lightning (other than direct strikes to the house). .
A great deal of the protection is keeping the ground references for power and phone and cable at the same voltage. That requires *short* ?ground? wires from phone and cable entry protectors to the earthing wire at the power service.
Keeping the ground references for power, cable, and phone together is a major part of how plug-in suppressors work. .
. A UPS will let the protect equipment power down gracefully. But they can?t disconnect fast enough to protect against a surge. A lightning induced surge might be over in 80 microseconds. .
. Perhaps you could provide sources that support your opinions. I can find you a source for most of what I have written in this thread.
. Poor w_ just ignores what does not fit his rant. Repeating "One of the early [tests] is a series of 20 surges. The suppressor can not fail during that test." .
. Not since the 1998 revision - as w_?s own handford link said. And still missing - a link that says a damaged suppressor even had a a UL label. .
. Provided often and ignored by w_. For instance about 2 months ago in this newstgroup.
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w_ refuses to answer 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 IEEE guide say (for long phone entrance ground) "the only effective way of protecting the equipment is to use a multiport [plug-in] protector"?
And still never seen - a source that agrees with w_ that plug-in suppressors do NOT work. Gee, maybe nobody in the known universe agrees with w_.
You are confusing a UL safety standard for all electrical appliances with UL1449 that only applies to surge protectors.
Take a power strip as an example. All power strips must have a 15 amp circuit breaker or fuse to comply with UL's safety standards. But when the power strip also contains MOVs, then that power strip must also comply with UL1449. UL1449 does not apply to a basic power strip.
UL1449 standard was created on 28 Aug 1985. Other appliances have complied with other UL standards long before 1985. Appliance without surge protection circuits need not comply with UL1449. As posted previously:
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