Power Surge & Blown Fuses

IF the power surge was a result of the Power Companie's equipment and you can somewhat prove it, THEY may end up repairing or replacing your set. I've seen it done locally. Give them a call.

L.

Replace the fuse *once* with one of the *correct* rating and try it. If it blows again then you have further damage.

snipped-for-privacy@gmail.com wrote in news:1158287694.903551.127360 @i42g2000cwa.googlegroups.com:

I thought that this is exactly the situation surge protectors are supposed to guard against. Aren't they supposed to sense the surge and trip their own breakers *before* the surge gets to whatever is plugged into them?

How did the surge make it through the surge protector and into the tv to blow the fuse?

Fuses require tens of milliseconds to trip (blow). Surges do damage in microseconds. Fuses and circuit breakers don't stop or block surges

- too slow. Circuit protection devices trip to protect humans after a higher energy source (AC electric) powers through damaged appliances.

Try replacing fuses. Fuses are cheap. You may get lucky. But protecting hardware from damage is not from a fuse / circuit breaker purpose - too slow.

Meanwhile, if utility failure (as another suggested) created high voltage, then utility should pay. Any l> We had a power surge, a rather large one. It trip most of the breakers

Power system surge suppressors are usually based on MOVs. A MOV clamps the voltage between 2 wires (like a bidirectional Zenier diode). The clamp voltage is low enough to not damage equipment connected downstream. If you have a surge on an incoming hot wire and you clamp the voltage from hot to neutral in a service panel, the voltage on the neutral tries to rise. Since the neutral is connected to ground/earth in a US service panel the surge is shunted to ground. Currents of thousands of amps can result, but max few millisecond duration since a surge is by definition a short duration event. Effectiveness of protection depends on the current and duration of the surge versus the ratings of the surge protector. Plug-in surge protectors may have low protection ratings. MOVs hit with surges near their ratings will deteriorate and eventually fail.

High earth current will locally raise the earth potential. If other connections, like CATV, do not have their entry protectors tied with short connections to the neutral-ground connection point at the electrical service, thousands of volts can appear between power wires and CATV. If a plug-in surge suppressor is used, the CATV, phone and other wiring to a device has to go through the suppressor so all wires are clamped to the common ground at the suppressor.

A good guide on surges and protection from the IEEE is at:

and from the NIST at:

bud--

Surge protectors are largely snake oil, they can help some in some situations, but a severe surge will blast right through one. The circuit breaker in the surge protector is far too slow to trip in time to fully protect the device.

James Sweet introduced reasons why a plug-in protector does not provide protection. Protectors don't stop, block, or absorb surges. To do that, a protector must be a series mode device. But it is a shunt mode device. Protector is effective if it shunted (connected, diverted, clamped) a surge to earth. But protectors without earthing (a problem when adjacent to the tv) cannot be effective. No numerical specifications for each type transient are published by that protector manufacturer. Even manufacturer does not claim protection you assumed existed. So myths are promoted based upon word association: surge protector sounds like surge protecction - therefore it must provide protection.

A surge not earthed before entering a building may overwhelm protection already inside the tv. One effective protector (because it is earthed) for all household appliances that costs only $1 per protected appliance and that is provided with responsible manufacturer brand names such as Square D, Siemens, Cutler-Hammer, Intermatic, Leviton, or GE. How much did you pay for a protector that was too small and does not even claim to protect? A daming statement. Where are numbers that define proetction?

True only if you have surge suppressors that rely on breakers for protection, in which case it would not be considered a surge suppressor, otherwise bullshit. Virtually all surge suppressors now use MOVs. They are effective if adequately designed and installed. Do some reading in Bud's links and look at how the better surge suppresors are designed.

Leonard

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James Sweet's comments appear to be applied to all surge suppressors and provided no reasons why they don't work, unless you have changed your mind and think protectors work by using circuit breakers.

As is clear from the IEEE guide, plug-in protectors work primarily by clamping, not series mode, shunt mode, stoping, blocking or absorbing. Your religous view that "protectors without earthing ... cannot be effective" appears to prevent you from understanding the IEEE and NIST guides.

I am astounded that SquareD is on your list of "responsible manufacturers" since their literature does not provide "numerical specifications for each type transient". Please review the other manufacturers and provide a link to "numerical specifications for each type transient" from one of them.

The IEEE and NIST guides clearly say that plug-in suppressors are effective. Links to sites that say plug-in suppressors are effective: 2 Your links to sites that say plug-in suppressors are not effective: 0

bud--

Amazing that bud still posts his ... well bud represents interests of plug-in protectors manufacturers. He cites a papers that demonstrate an SRE concept, defines notes how the concept is compromised, and then recommend the well proven and recommend protection method (ie 'whole house' protection). What does effective protection have and plug-in protectors don't? Dedicated earthing connection. From a conclusion in bud's own citations:

What does NIST and IEEE recommend?

Bud simply distorts a paper that says SRE protection (a protector without earthing connection) can work. Bud forgets what that paper says; that even a kid with an Xbox can violate that protection. Remember, bud promoted plug-in protector manufacturers. Effective protection is defined by IEEE Red Book (IEEE STd 141) and IEEE Green Book (IEEE Std 142):

and

Meanwhile, author that bud repeatedly cites also says that plug-in protectors can even contribute to electronic damage:

Paper that bud cites do not say that plug-in protectors are effective. Bud cannot even define effective - so that he need not admit why plug-in protectors are both ineffective and so often grossly overpriced. Bud's own citations even say the properly earthed protector is a superior solution. Bud intentionally would confuse you by citing the concept, then proclaiming a technical description as a recommendation. This post but again a warning about those who promote grossly overpriced and typically undersized protectors - that are so profitable.

To quote w_: "It is an old political trick. When facts cannot be challenged technically, then attack the messenger.." I have nothing to do with surge protectors.

The guides don't mention Xboxes. In case anyone doesn't understand w_, he claims the guides say using a SRE requires difficult engineering, considering the whole room. The guides show simple application of SREs. Claiming difficult application is stupid.

To take only one example: the IEEE guide, chapter 6, "Specific Protection Examples," shows 2 examples of surge protection. Both use SREs. Saying both guides waste a lot of space describing SREs that are not effective is stupid. Repeatedly making this claim requires willful stupidity

The IEEE and NIST guides clearly say that plug-in suppressors are effective. Links to sites that say plug-in suppressors are effective: 2 Your links to sites that say plug-in suppressors are not effective: still 0

bud--

I saw a photo of a cheap suppressor that had clearly had a serious hit. It was hidden behind furniture and the customer didn't know until he moved because the equipment continued to run OK.

The IEEE guide talks quite a bit about wiring the protected load across the MOVs, which will disconnect the load when the MOVs are disconnected, or wiring the protected load so it is not disconnected. There are potential advantages both ways. I believe UL now requires suppressors that don't disconnect the load with the MOVs to state that (could be in the guide).

UL also now requires MOVs that overheat be disconnected. Before the change plug-in suppressors could melt the plastic case.

The former NIST guru on surges, who wrote the NIST guide, has said most MOV failures (I presume service panel and plug-in) are a result of overvoltage, not surge.

bud--

IOW plug-in protectors are for profit - not for effective protection. Many are grossly undersized. When it fails or vaporizes (operates outside of what MOV manufacturer datasheets define for acceptable operation), then that protector is recommended by the naive to the naive - more sales. Best to make plug-in protectors undersized. Ask yourself. Do you want these devices behind a desk or on the rug. These are what Bud is promoting as effective protection:

Just another reason why 'whole house' protectors are so effective. Properly sized so that the surge is earthed - and homeowner never knows a surge existed. That is how surge protectors performed even 50+ years ago.

They don't have the necessary earthing connection. They must do something to sell their ineffective products. One way is to undersize the protectors. However, that can have dangerous consequences.

As you very well know, and as I stated in the quote above, UL "now requires MOVs that overheat be disconnected." Your scare tactics are pathetic.

One can certainly get undersized protectors. That is why the IEEE and NIST published guides, and why I posted links to them.

And the required statement of religous belief again. As the IEEE guide explains to those who can read, plug-in suppressors work primarily by clamping, not earthing.

The IEEE and NIST guides clearly say that plug-in suppressors are effective. Links to sites that say plug-in suppressors are effective: 2 Your links to sites that say plug-in suppressors are not effective: still 0

63,458,237 pages on the internet and noone agrees with you???

bud--

You appear to confuse popularity with proof.

If you want to understand something, asking those with $ to make out of it is not the way. The route to knowledge is to ask those with skills qualifications and experience in the science and engineering of the matter.

Obviously those with $ to make will seek to convince potential buyers of the value of their overpriced undereffective products.

NT

Facts that Bud routinely forgets to mention from his citations. Figure 8 from his own citation shows two televisions connected a plug-in protector. Both televisions then go to 8000+ volts during a massive surge. Somehow Bud assumes this is protection. Somehow, Bud assumes other conductive materials in that room (floors, walls, other AC receptacles, pipes, etc) do not compromise that protection. Somehow Bud claims that equipotential alone provided protection. And so Bud routinely forgets a very first conclusion made by Martzloff, et al in an IEEE paper:

Do we install expensive plug-in protectors even for dishwasher, smoke detectors, bathroom GFCI, clock radio, dimmer switches, etc? Of course not. We spend tens of times less money for a protector that does both equipotential and does conductivity; what a plug-in protector cannot accomplish (because it does not have that earthing wire).

One 'whole house' protector, properly earthed, provides both conductivity and equipotential for everything inside a building - at about $1 per protected appliance.

Protectors properly sized so that these scary pictures need not occur:

Disconnecting undersized MOVs is a backup system. When protectors use grossly undersized MOVs then human safety is dependent only on a backup system.

Bud promotes for the plug-> As you very well know, and as I stated in the quote above, UL "now

For those who can read, the IEEE guide cited uses Fig 8 to explain how SREs work. For those who can read the IEEE guide clearly recognizes plug-in surge suppressors as effective.

The application of SREs in the IEEE guide is simple and straightforward. Your claims that engineering expertise is required, considering the whole room is nowhere in the guides or any other paper and is willfull stupidity.

One of the authors of the Upside-Down house papers was Martzloff, who wrote the NIST guide which recognizes plug-in surge suppressors as effective. Another author was Dr. Mansoor. Yor previous comments provoked the following from an EE: "I found it particularly funny that he mentioned a paper by Dr. Mansoor. I can assure you that he supports the use of suge equilization type plug-in protectors. Heck, he just sits down the hall from me. LOL"

Progection decisions are a tradeoff of progection cost, risk and value of protected equipment. Protecing a clock radio wouldn't make sense. Protecting a home theater system does. As does protecting a computer, primarily because of the value of the data and software contents and the time required to set up a new one.

And the required statement of religious belief.

A repet of your pathetic scare tactics. As stated previously, UL standards now require disconnect of failing MOVs.

And the political trick back again.

The IEEE and NIST guides clearly say that plug-in suppressors are effective. Links to sites that say plug-in suppressors are effective: 2 Your links to sites that say plug-in suppressors are not effective: still 0

bud--

I really don't understand your comments. What I have said is consistently based on the IEEE guide at:

and an equivalent guide from the NIST at: They guides were writen by 6 EEs as guides to the general public on surges and surge protection. I don't where you could better find people with "skills qualifications and experience in the science and engineering of the matter" than the IEEE and NIST. The author of the NIST guide has written many published papers on surges and protection.

I have not quoted "those with $" in this thread and have never used them as authorities.

bud--