What's the point of surge protectors?

[JohnnyTheRed]

Isn't the point of a fusebox to prevent spikes in the circuits of a house? Why bother having a surge protector if the fuse will blow and stop it? Or is it not instantaneous, and some extra voltage does get through, so that's why it's good to have a surge protector there?

Also, if a bolt of lightning strikes a transformer/telephone pole/wire in the area near your house, what happens? Does the extra voltage carry down the line into your house? If so, would the fuse box stop such a high current? Would a surge protector help against this?

[JDXNC]

Fuses don't stop high amounts of voltage. If you ever felt an extention cord powering something drawing a lot of power, such as an AC, they get warm, not because of the voltage but the high amperage draw. Fuses/breakers have a set point that when something draws too much power, or therte is a short in the line, it shut off the power so the wiring doesn't overheat and cause a fire. Lightning is just a high amout of voltage, and tends to go right through fuses and breakers.

[su root]

.. and if lightning strikes right outside your home, chances are it'll fry most of your stuff regardless of breakers/fuses and surge protectors.

I highly recommend buying surge protectors that give you a guarentee on equipment connected to it. Most of the better surge protectors carry this guarantee. That way, if something does happen, you can make a claim and possibly get back some money for any equipment you lose.

[JohnnyTheRed]

I do recall seeing guarantess on equipment attached to a surge protector. So is this the only real reason to use one? In case something does happen, you can put in a claim with the company?

I use them on all my important things, and usually shutdown adn unplug comps during storms, btu I was jsut wondering about it :)

[su root]

Unplugging is the best.. unfortunately, very few people go that far. (I know I don't).

The surge protectors have what's called a "clamp voltage", which means if there is a power spike, or surge, higher than the clamp voltage, it will pop the clamp, and disconnect everything to avoid damage. Lower clamp voltage is usually better (clamps quicker).

The guarentees are basically like insurance policies. If their product fails you, you can claim against it, and probably get back the money for whatever was connected to the surge protector. I havn't claimed against one yet, but most UPSes come with that same (or better) guarantee.

[JigPu]

A fuse/circut breaker is designed to prevent large current draws from occuring on one circut. If you have too many things plugged into the same circut, it is possible that the wires in your house may melt the insulation and start a fire. The fuse/circut breaker DOES NOT prevent voltage spikes from occurring (though they can also cause them to blow/trip).

A surge protector however, is designed to protect against excess voltage. It acts kinda like a sponge, absorbing many little spikes over time, or perhaps one big spike. A surge protector, like a sponge, will eventually run out of capacity and stop absorbing these voltage spikes though. At this point, you'll need to replace your surge protector. It should have a light that goes off when it looses it's protection, notifying you to replace it.

I've never lost equipment (even if it's not on a surge protector), because of surges (just had one about 10 days ago) but it makes me feel safer knowing that my computer is getting no more than the voltage that it needs.

If lightning struck though, I'd expect both the breaker AND the surge protector to go off. Hopefully, the surge protector's clamping time would be small enough that everything on it survives though.

JigPu

[su root]

Originally posted by JigPu
It acts kinda like a sponge, absorbing many little spikes over time, or perhaps one big spike.
That sounds like a surge surpressor...

[star882]

I have APC UPSes, and one time, lightning struck very close to the building, it managed to take out a dimmer switch, but the computers aren't affected in any way.
http://www.uploadit.org/files/120703-apc.JPG

[su root]

Originally posted by star882
I have APC UPSes, and one time, lightning struck very close to the building, it managed to take out a dimmer switch, but the computers aren't affected in any way.
[IMG]
I've heard stores of UPSes MELTING after a lightning strike, or even exploding (and sending the battery acid everywhere).

Personally I run an APC UPS. Gets me a good 8 minutes or so. Saved my butt way too many times to mention. There was a "what line protection do you use" poll just recently.. (can't find it right now) might want to check that one out, it's got a lot of good opinnions in it.

[star882]

"I've heard stores of UPSes MELTING after a lightning strike, or even exploding (and sending the battery acid everywhere)."
I think that's what the cheap UPSes do.
APC UPSes are most likely well designed.

[huneycutt]

Suffice to say surge protectors are a bunch of hooie. Only way to go is with a battery back up that protects you from high AND low voltage which can be just as damaging as high voltage. I use the APC 500 $60. at Staples and the 350 $40.

Let's say you use a surge protector and the power goes off or surges just enough to do a cold shut down on your computer and cold shut downs are one of the worst things you can do to a computer. Neat thing about the APC battery back up is if the power goes completely off it has a software program you install with the CD that comes with the battery. It's called Power Chute and it automatically closes out all the things you have running and then shuts down the computer in a normal fashion just as if you had saved all your work then selected "Shut Down" from the Start menu. You lose nothing and your computer is happy, happy, happy.

Let me tell you just how good APC works. One morning I was about half way through burning a music CD and the lights flickered and surged three times. I figured I had me another coaster for sure. WRONG! NOT! The 'puter never knew there was a surge because APC kept a constant power flow going and the burned CD was perfect.

Let's get real here folks. You mean to tell me you throw down your hard earned cash and put all that time and energy in researching then building a fine 'puter and then won't spend $40. bucks to protect it? Talk about cheap insurance for a big investment . . . .

Take that surge protector and put it away and get yourself a good battery back up. I don't own stock in APC but I know they work. Let a word to the wise be sufficent. Have a great week end. OC

[four4875]

i want to get a UPS some time. my house's power is SOOO choppy. i need to get a straight transformer and plug it in and hook my scope to it, theni can see how bad it is... hehe

[huneycutt]

You got that right four4875. So bad here in SC we come home four or five times a week and find the digital clocks blinking or the touch lights on, our "surge monitors." We always shut the 'puter down before leaving for work but the surges happen at any hour.

Darn it, we all pay for "clean" electricity so let the electricity providers deliver a good product like any company that provides a service should do. Problem is, we can't tell them to kiss off because in my opioion South Carolina Electric & Gas is as sorry as they come but they're all we can get. Suckers always getting a rate hike while ten of the top ten SCE&G big wigs make over a million dollars a year salary. Ain't that a kick in the voltage meter backside? Please forgive, this ain't a political website but thanks for letting me vent.

Be smart, go spend the bucks and get yourself a good battery back up.

[su root]

I have fairly clean power around here. There is the occasional power out (one every few months), but last summer, our area got hit bad, and there was rolling blackouts throughout the day. You can imagine how many times it allowed me to save my work and properly shut down at the end of our power cycle.

[star882]

"Only way to go is with a battery back up that protects you from high AND low voltage which can be just as damaging as high voltage."
Actually, low voltage is probably more damaging to modern PSUs than high voltage, since the switching transistors in modern PSUs are rated for about 900v, low voltage would cause high current(because a PSU is pretty much a constant-power load), which may put the peak current over the transistor's rating.
I have heard some stuff about air conditioners tripping breakers during a brownout, I think it's because the linear PSU inside the air conditioner uses 2 SCRs to control the power entering the power transformer(cheaper and more effcient than using transistors in the low voltage line, but the output will be more choppy, which is OK for peltiers), then the driving circuits gets messed up by low voltage, causing one SCR to stay stuck on, and because a transformer primary is virtually a short circuit to DC, the breakers trip from overload.
The SCR usually survives because they are rated for high surge current.