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@ Westom " And finally, UL says nothing about hardware protection. UL is only and completely about protection of human life. Who is the UL? National Fire Protection Association." Um, not to confuse what you've written with actual facts, but UL (Underwriter's Laboratories) and the NFPA (National Fire Protection Association) are two separate and distinct organizations. Further, while UL is obviously concerned with human life, their standards are written to help protect devices and structures as well. "Only and completely about protection of human life" is an incorrect statement. Sorry. |
Correctly noted is my mistake with NFPA and UL. Both are separate and address human safety issues. Both address device protection and structure protection relevant to human safety. Neither says anything about quality of product functions. Otherwise a UL number that says "how" good is provided. No number is provided because none exists. UL only tests for threats to human safety. UL1449 says nothing about protecting appliances from a destructive surge. It only discusses protection of humans from a protector failure. Protector can be grossly undersized and still be UL listed as long as it fails in a manner that does not threaten human life. A protector can fail catastrophically during a UL1449 test. Still be UL listed even if it does near zero protection for an appliance. No way around reality. Effective surge protection means one can say where hundreds of thousands of joules harmlessly dissipate. Where does UL discuss that number? It doesn’t. UL is not about appliance protection. UL is only about human protection - ie it spits no sparks and flames. A plug-in and UL listed protector (ie type 3) must be distant from the breaker box since being too close to earth ground means that tiniest protector can be a human safety issue: http://www.nemasurge.org/what-is-spd/ Effective protection means a destructive surge (ie 20,000 amps) is connected low impedance (ie less than 10 feet) to single point earth ground. Then hundreds of thousands of joules are not inside blowing through near zero plug-in protectors. Where does a naysayer discuss these or any other relevant number? No numbers means a denial is bogus. At best, probably wild speculation. Informed consumers learn to ignore recommendations that are subjective. Subjectively recommended were ineffective and grossly overpriced products from companies such as Furman and Monster. Not one manufacturer spec number from Furman or Surgex is posted. Because neither claim to protect from destructive surges. Such products are marketed to consumers who only want to be told what to buy. And get angry when spec numbers (reasons why) are discussed. Posted were direct quotes from professionals who know and do this stuff. Why does one know this stuff? Because one was doing it even before an IBM PC existed. Why is well understood science denied by another who also ’feels’ treble is opened up? Power to an amplifier’s transistors is unchanged by series mode filters. Amplifier power still comes from filtering and regulating well over 300 volt radio frequency spikes. Those spikes exist with or without a series mode filter. Why would sound from transistors change when nothing into those transistors changes? Somehow ’feelings’ justify science. Bulloney. Circuits make cleanest AC voltages into well over 300 volt radio frequency spikes. Then clean that ’dirtiest’ power. Best protection is already inside high end amps. Consumers concern is an anomaly that can overwhelm that already existing and robust protection. That means earthing a best solution (that costs about $1 per protected appliance). Then even direct lightning strikes (ie 20,000 amp) are made completely irrelevant by this device rated at least 50,000 amps. Best protection is also a least expensive solution. With numbers that say why. Best protection for high end amps and other other appliances means one knows where hundreds of thousand of joules are harmlessly absorbed. Done by UL approved devices that meet or exceed above numbers. And not done by UL approved devices that only claim to absorb near zero joules. Both are UL approved since human life is not threatened. But only a properly earthed solution claim to protect from what might be destructive. Consumers are warned that ineffective and near zero joules devices are only recommended when no supporting facts and numbers are provided. Just as foolish is to assume UL tests product performance like Consumer Reports does. A near zero (ineffective) protector can still be UL listed as long as it does not threaten human life as it fails prematurely. Best protection for high end amps always was a ’whole house’ solution, rated at least 50,000 amps, and with a low impedance (ie less than 10 foot) connection to single point earth ground. |
Series mode surge protection devices have the best (lowest) UL tested "let through voltage" or VPR for test surges. meaning that during tetsting the equipment being protected would suffer a much lower voltage than with MOV parallel devices. Difference between longitudinal mode and metallic mode currents was never learned. That is even taught to every first year engineering student. So the engineer will again expose a half truth in a let-through voltage assumption. Assume a 5000 volt surge is incoming on the hot (black) wire. If approaching a typical protector rated at 330 let-through volts, then 5000 volts is still incoming on a hot wire. And 4670 volts is incoming on a safety ground (green) and neutral (white) wire. Where is protection? If a surge has a lower let-through voltage, then that 4670 volts increases closer to 5000 volts. Without first year electrical knowledge, well, demonstrated is why a near zero (600 joules) filter was recommended to somehow avert hundreds of thousands of joules. And why a near zero joule solution is recommended subjectively. By discussing this one spec number, demonstrated again is why advertising (not science) was the source of that recommendation. Please learn what a let-through voltage measures before making recommendations. Please post numbers with your every recommendation to learn about basic electrical concepts you did not know. Recommendations without citing the relevant specification number is best ignored as if junk science. |
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