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Thread ID: 90974 2008-06-22 02:48:00 Surge protectors jwil1 (65) Press F1
Post ID Timestamp Content User
681033 2008-06-22 02:48:00 Are SPs connected to PC's overrated?

In other words, should I get one - and if so, what should I protect?

I have 1 new PC, 22" monitor, home network switch + a few other cheap devices (speakers, lamp) and a few old machines that probably don't need protection.

These are on a powerboard with a overload switch on it - I assume this is different to a SP?

TIA
jwil1 (65)
681034 2008-06-22 03:11:00 It depends if the power board says surge protection on it.

If it does, it'll do the same thing. If it doesnt then no its not the same thing
Speedy Gonzales (78)
681035 2008-06-22 03:17:00 Its a nice to have, and generally they work. Id rather have my adapter pop then my pc. rob_on_guitar (4196)
681036 2008-06-22 03:17:00 Also, How reliable are they??

My block is an uber-cheap $10 8-way powerboard (HPM brand). Probably 3-4 years old. So I don't think it has a SP built in.
jwil1 (65)
681037 2008-06-22 05:18:00 I just have a Belkin surge protector which has 4 plugs on it. It costs $130 but I got it free but it works well and there's no harm in using one is there? beeswax34 (63)
681038 2008-06-22 06:26:00 Also, How reliable are they??


that a good question which no one really has much of an answer .

not many tests of them have done that i know of . consumer mag did a good test years ago and found a lot didn't do anything .
most likly the cheap ones won't do anything much BUT some of the exspceive ones are not any better .

i've pulled some $100 + ones apart to find the same bits in them as a $20 one .
i've seen some that where labbelled "will not potect over xyz voltage" if i remeber correctly that voltage was actually the PEAK voltage for 240 mains . so its a fancy way of saying it doesn't do jack :horrified

also just recently was shown a MOV block that plugs into a spare fuse block on the switch board . its meant to protect the house but i doubt it do jack . it didn't have any indicators on it to tell you if its "used up" or not . so the first stike kills it, the 2nd kills your gear .

it get the fealing that surge protection in NZ is just a con job dispite there being some excellent products on the market . tho we do miss out on some which are common around the world .

a good basic setup you can do is fit a lightning diverter on the incoming mains line . it only works on high voltages, won't do anything with below 1000v's but it wil take the big hits so your cheap surge protectors can survive long enough to actually do something .
tweak'e (69)
681039 2008-06-22 08:06:00 Your right tweak'e, most of them wont do anything. They are designed to protect against surges that are so small, that they lie within the tolerances of most appliances. Big surge comes....whammo bye bye surge protector and bye bye appliance.

The best thing to do is disconnect appliances during storms, which is when surges are most likely to occur.

In saying that, I thought I'd better do some research before I ranted, looked on the PDL website and these: www.pdlglobal.com

..seem to be rated quite well, but who knows how much they cost.
pine-o-cleen (2955)
681040 2008-06-22 09:50:00 Surge protector is really a mismomer in this application, especially if solely reliant on MOVs (metal-oxide varistors, otherwise known as voltage-dependent resistors or VDRs).

A surge is a rise in voltage of relatively lengthy duration (milliseconds to seconds or more) and within reason they are not particularly harmful to computers because most computer power supplies can easily withstand surges of up to 15-20%, and the NZ power system does not produce many surges of any significance.

MOVs do not respond to such surges because their breakdown voltage is much higher and since most "surge protectors" are nothing more than MOVs they are largely a waste of money from that perspective.

What will cause major problems are voltage spikes and these can easily reach thousands of volts. MOVs are effective in clipping these transient voltage excursions down to levels that will cause no harm, but every spike that hits an MOV erodes part of the core material away and in time the MOV will cease to be effective. Unfortunately you rarely have any way of knowing when your MOV(s) stop working, but they should last several years in a domestic environment.

There is only one "surge protector" on the market (that I know of) that can tell you when it is about to give up the ghost, and it does that by having multiple MOVs in a two stage filter system configured so that when the first stage made up of several MOVs in parallel finally dies, a green LED goes out to indicate that all primary protection has ceased. You then have a few days, weeks, or months, depending on how spiky your power is, in which to replace it before the single MOV that provides the secondary protection is expended. It is not cheap!

Surge filters built into the average power board are useful for spikes only, but give no warning when time expired!

Cheers

Billy 8-{)
Billy T (70)
681041 2008-06-22 10:28:00 ......... but they should last several years in a domestic environment.


hate to disappoint, but most are one shot wonders.

majority of them are single MOV or at best MOV. for any decent protection you really need banks of them.
some of the USA ones ive seen advertised look good. multiable banks, indicator light per bank, mounted externally to the house with earth peg directly underneath.

mind you thats where a diverter is quite good, don't try to handle the spike just dump it directly down to earth. a crude homemade version is a spark plug !

also a lot of sentive appliainces have there own MOV's built in.
i've repaired a fair few over the years. a small catch i've come across is people have a blown fuse in the applaince but fail to check the MOV in it. generally its fried and they only replace the fuse. months later applaince is faulty with major circut board tracks blown off it !
tweak'e (69)
681042 2008-06-22 11:33:00 Wainuitech has had some experience with these and UPS's.
pressf1.co.nz
feersumendjinn (64)
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