Just now for no apparent reason (there’s a clear blue sky out), the power shut off momentarily, then cut back on, then shut off again, then flickered a little. My computer came right back up, but my girlfriend’s computer won’t turn on now. The cable box and phone went out too. The cable box came back up after a while, and we got a dial tone, but the date was wiped out and had to be manually re-entered. The big worry is her computer.
What’s weird is how hers was plugged into an expensive surge protector, while mine was un-surge-protected.
Surge supressors are kinda like buletproof vests…good to have when you get hit, but not a guarentee you wont get hurt.
All electronics can fail under such circumstances. In this situation a power supply can be a common point of failure that is easily replaced by a computer shop or even a novice thats not afraid of a screwdriver. Any computer shop has a tester that will tell you if a PSU is bad, takes about 30 seconds.
not to say that it cannot be more than a PSU but about half of the machines that come into my shop “no fire” will work fine with a new PSU.
Also it is extremely rare for significant data loss under such circumstances. It can happen, but in my experience, the drives are perfectly readable without any “advanced data recovery” beyond running a windows tool called “chkdsk” over the drive to sort out any disruptions of the file system from the unplanned shutdown…
I agree with Baracus and UncleRejelo. This is a great first step!
My surge protectors have a reset button that sometimes gets tripped in such a circumstance.
Computer contain numerous hardware protection features. For example, protection can create a lockout. To clear that protective lockout, its power cord must be disconnected from an AC receptacle.
Just one of many reasons that might explain her temporary failure. But power loss does not cause hardware failure.
A circuit breaker on power strips is for human safety. It does not protect hardware. Every power strip (protector or not protector type) must have that circuit breaker. Breaker can be reset after a hardware failure has tripped that breaker. First fix the reason for a breaker trip.
Good surge protectors stop supplying power if they’re spent, that way you know they need to be replaced. You need to be careful with those that, after a surge, aren’t protecting anymore, but still provide power.
Most surge suppressors these days use MOVs. The way these work is that the MOVs “turn on” in an overvoltage situation, and essentially make a short circuit to ground which shorts out the surge and (mostly) prevents it from doing any damage to your equipment. This is usually a one-shot deal since the MOVs are often destroyed in the process. Your typical surge suppressor gives you no indication at all when your MOVs are blown.
The MOVs also only protect you from overvoltages. They do not protect you at all from brownouts (undervoltages) or power that is flickering on and off. Both of these conditions can be deadly to electronic equipment. If you want protection from these, you need something like a UPS. The OP probably experienced something more like this, which is unlikely to result in a surge, though a surge or spike is possible when power flickers on and off due to energy being stored in inductors (like a power transformer) and that energy may create a spike when power is suddenly removed and the magnetic field in the inductor collapses.
In the OP’s case, since the power was probably flickering and no overvoltage was probably present, the surge protection likely didn’t really come into play at all.
Circuit breakers provide very little safety protection for humans. Their main purpose is fire prevention. Ground fault circuit interrupters (GFCI) protect humans.
A circuit breaker prevents a major electrical fault from causing a fire. An arc fault circuit interrupter (AFCI) prevents minor electrical faults like frayed extension cords from causing fires.
I have never seen a power strip that includes a GFCI or an AFCI. GFCIs have been in common use since the 1980s, and unless your house is older than that, you’ll probably have them in your bathroom and kitchen outlets. AFCIs are much more recent. and have only been required in new homes since the last decade or so.
In addition to using power strip type surge suppressors, you can also get whole house surge suppressors to protect everything in your house. These are a bit more involved than just plugging in a power strip and will require an electrician to install.
When looking at surge suppressors, the two things you want to look at are the clamping voltage (lower is better) and the joule rating (higher is better). An el-cheapo power strip may be rated at something like 300 joules. A better one will be maybe 700 or higher. A whole house surge suppressor might be rated at a few thousand joules. Keep in mind though that a lightning bolt contains a few billion joules. Nothing you can buy will save you from a direct strike.
Protection from fire is human safety. A circuit breaker protects from all types of threats was not stated. Only that a circuit breaker is for human safety - ie to avert a fire that would otherwise harm humans. GFCI, RCD, AFGI, and other devices are even better circuit breakers. But again, only for human safety. Not for hardware safety.
So which is it? It disconnects the appliance from AC mains (“stop supplying power”)? Or it leaves the appliance connected to AC mains (“still provide power”). Does it disconnect the appliance or leave it connected? Why do you say a protector does both?
Bottom line - protectors leaves an appliance connected to a surge. Only disconnects protector parts as fast as possible to avert a house fire. A problem when the protector is grossly undersized (ie 700 joules).
OP describes functions inside all computers that make computers so robust. If a surge existed, those computers protected themselves. A grossly undersized protector disconnects its protector parts as fast as possible to avert fire.
Gagundathar is describing a circuit breaker; not surge protection. Protector parts cannot and must not be reset. Effective protectors earth surges (even direct lightning strikes) and remain functional.
I mean:
good protectors - stop supplying power after they lose their protection
poor protectors - still supply power even if they’re no longer protecting
The reason being that if there’s power, you assume everything is ok, and during the next surge everything gets fried. I read this as one of the features on a surge protector.
Open one up. Learn how these things are designed. Disconnecting device only disconnects protector parts (ie MOVs). Must do so ASAP so that a house fire does not happen. None disconnect the load (appliance).
To disconnect that fast, the thermal fuse must be so tiny as to not power any appliance. So tiny as to only connect to the MOVs; cannot disconnect any appliance.
Many if not most writings about protectors are based in hearsay, advertising, wild speculation, and urban myths. So uselessly subjective as to not even provide numbers. That thermal fuse must tiny to blow ASAP to avoid a house fire. That thermal fuse is completely different from a circuit breaker that all power boards (protector or non-protector type) must have.
Some superior technology protectors do not even have that thermal fuse. A disconnecting device is inside the MOV (the protector component). The protector device disconnects. An appliance remains connected.
A protector may fail during a surge too tiny to overwhelm protection inside an adjacent appliance. Failure promotes sales. Effective protectors do not fail after a surge. Effective protectors remain functional. Unfortunately, that does not get naive consumers to recommend it. Naive consumers can only recommend what was so grossly undersized as to fail. An effective protector even earths direct lightning strikes and remains functional. Nobody knows a surge existed when a protector is effective - does not fail.
Good protectors do not fail even after direct lightning strikes. Grossly undersized protectors promote sales by failing on surges too tiny to overwhelm protection already inside appliances.
I think we’re talking about different things here:
I mean surge protectors sometimes stop protecting after doing their job, like air bags. According to engineer_comp_geek, “This is usually a one-shot deal since the MOVs are often destroyed in the process. Your typical surge suppressor gives you no indication at all when your MOVs are blown.” However, you say, “Good protectors do not fail even after direct lightning strikes.” I am not talking about thermal protection.
Assuming the protection is lost, do you say it is better for the surge protector to continue supplying power, or stop supplying power?
A properly sized protector does not blow MOVs. Not a one shot deal. That type failure sells high profit and ineffective protectors to the naive.
How to test MOVs from one manufacturer’s datasheet:
> The change of Vb shall be measured after the impulse listed below is applied 10,000
> times continuously with the interval of ten seconds at room temperature.
Not one shot. 10,000 times. Vb is voltage an MOV starts conducting. An MOV degrades when that voltage changes 10%. Not vaporize. Not fail catastrophically. MOV only degrades IF properly sized. Energy levels required to blow, vaporize, or ‘one shot’ an MOV are well beyond MOV manufacturer’s Absolute Maximum Parameters.
A grossly undersized protector is a ‘one shot’ deal. Its protector parts must disconnect as fast as possible. Leave an appliance connected to a transient. Disconnect ASAP so that a grossly undersized MOV does not vaporize. Effective protection is inside the appliance. But a naive consumer will assume, “My protector sacrificed itself to save my computer.” Wild speculation (also called junk science reasoning) promotes sales myths. The appliance saved itself from a tiny transient.
On 20 Apr 2011 entitled “Safety Switches / Surge Protection”, melbourne architect reported the same problem:
> Cheap surge protectors have been known to catch fire (in one case, a Fire
> Station was burnt out; the red faced fireman later learnt it was due to the
> cheap surge protector/power strip in the office)
Spend $4 for a power strip. Add some ten cent protector parts. That protector now sells for $25 or $150. Profits are obscene. And fails catastrophically so that naive consumers will recommend and buy more.
How many protectors do you have on dimmer switches, clock radios, dishwasher, air conditioner, bathroom GFCIs, digital clocks, and smoke detectors? Why are each not destroyed daily or weekly? Because protection is same with or without an adjacent plug-in protector. Because superior protection is already inside each appliance.
A rare transient that overwhelms that protection occurs maybe once every seven years. One properly earthed ‘whole house’ protector makes that transient irrelevant. A properly sized ‘whole house’ protector also remains functional. Costs about $1 per protected appliance. No obscene profit margins. Why spend tens or 100 times more money for a ‘one shot’ wonder?
‘One shot’ devices do not have earth ground. Will not even discuss it. Do not claim effective protection in manufacturer specs. One shot devices fail so that the naive will buy more at obscene profits. A protector is only as effective as its earth ground. ‘One shot’ protectors do not have that always required earthing. Protectors actually designed for protection are not ‘one-shot’ devices.
Protection means it remains functional after each surge. Profit center means it fails catastrophically on a first surge. Abandons an appliance to protect itself. Do not know how to make that any clearer.
So you agree that all protectors will fail eventually. In the first 2 of your links, they mention “This unit continues to deliver power, and all lights and switches operate without any indication of failure.”, like it’s a flaw. This is my point. I’m saying better designed protectors stop delivering power (not during the surge, at all times) once protection is lost, so you know something.
Protection is not lost. Even when degraded, a protection is not lost. Failure mode for properly designed protectors is to degrade. Protection still exists.
Those indicator lights only report a protector was so grossly undersized as to fail catastrophically or disconnect to avoid a fire. Lights say virtually same protection existed with or without that protector. And similar protection exists after the adjacent protector has failed catastrophically. Because best protection at an appliance was inside the appliance.
How often does a ‘whole house’ protector fail? Well, 33,000 volts fell upon the local distribution. The resulting surge was so massive that electric meters were blown 30 feet from their pans (at least 100 of them). Many who had power strip protectors had failed appliances and protectors. At least one had a failed circuit breaker.
But my friend knows someone who knows this stuff. He had one ‘whole house’ protector properly earthed. And no damage (except to his electric meter). Even the protector was undamaged.
Yes, all protectors eventually fail. All roofs also eventually fail. Everything fails if reasoning subjectively. Same facts with a different perspective - numbers - mean a completely different conclusion. Subject reasoning means concerns over something trivial. Informed homeowners earth one ‘whole house’ protector so that even the protector is still good a decade later (often longer).
Protector failure is a concern when a protector is nothing more than a $4 power strip with some ten cent protector parts. A profit center selling for $25 or under the Monster label for $150. Protector failure is rarely a concern when manufacture spec numbers meet previously defined minimums. Install a protector so that protector failure is not a concern. And so that most money goes into protection - not into an obscene profit margin.
And finally, appliance power should disconnect if a protector has failed? Why disconnect? So that another surge does not enter an appliance? How would a millimeters disconnecting gap stop a surge? Three miles of sky could not stop it. How does a millimeters gap stop a second surge? Also how does one disconnected wire (ie black wire) stop a surge from entering on two other wires? It doesn’t. Solutions are found in protectors that are properly sized and earthed (and that also cost tens of times less money per protected appliance).
I believe the expression is, “Do it right the first time.” Then protector failure is a trivial issue.
I know I’m wasting my time responding to you, but not all surges are from lightning strikes, so not all surges can pass through “miles of sky”. The breakdown voltage of air is about 3 kV/mm, so a 2 or 3 mm gap could stop a surge up to about 6 to 9 kV.
To stop a surge means wires must have more than a 3 mm gap. Cannot happen for many reasons starting with human safety requirements.
Unnecessary is to disconnect anything when the protector fails. Because a protector should be sufficiently sized to not fail. But when selling a $4 power strip with some ten cent protector parts for $7 in the grocery store. Or selling a same protector for $25 or $150 under the Belkin or Monster labels. Then protector failure is necessary to promote more sales.
Fix the problem. Disconnecting does not address a protector that does not even claim effective protection in its numeric specs. More reasons why informed homeowners spend money wisely on upgrading single point ground and one properly sized ‘whole house’ protector.
That one point (a 3mm gap) is valid. But most switches do not create gaps that large. Also ignored are other posted facts. An open switch never does effective protection for many reasons. And does not solve the actual problem.
Meanwhile, the OP’s protector did the same ‘nothing useful’. Superior protection inside a computer apparently kicked in.
I think you’re right about that. There was no bolt from the blue, no surge. Instead, it was the hottest part of the afternoon on a really hot day, and everybody’s air conditioners demanding too much power caused it to hiccup, is what must have happened.
I’ve tried to follow the rest of the discussion, but it’s getting a bit too technical for me. Are you debating whether surge protectors ought to be used at all, or about how they work, or ought to work, or what? Can anyone gist the main points to recap, hopefully not too technically worded?