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Are PC surge protectors needed in the UK?

Discussion in 'Electronic Repair' started by Lem, Jul 8, 2004.

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  1. Lem

    Lem Guest

    Are surge protectors on the main power supply actually needed in
    the UK?

    here in the UK we have few overhead mains power lines and have a
    relatively steady mains power supply when compared to many other
    countries (including the US).

    However there seem to be very many surge protector products
    advertised for sale in the UK (Argos, Maplins, etc).

    I am quite sure it is not bad practice to use a surge protector but
    in fact I have never known anyone who has has a problem from a
    surge coming in through the power supply.

    So personally I don't bother using a surge protector on my PC.

    Am I being too complacent?
  2. greywolf42

    greywolf42 Guest

    It all depends on your tolerance of risk.

    It doesn't have to hit a power pole. A friend of mine lost 2 PCs when
    lightning hit a tree next to her house, then jumped to the house (knocking
    some siding off in the process).

    Surge protectors are cheap. Or just back up your data regularly.
  3. No, at least not to protect PCs.
    Lots of people run a particular OS which is known for its
    instability, and you can sell them just about anything if
    you suggest it might make their systems more stable. Of
    course it doesn't, but that just means they'll try something
    else (except changing the OS;-). Surge protectors are one of
    the many items on the list that such people will try.

    The other issue is that the multi-way trailing socket blocks
    got down to the point where they're only a couple of pounds
    each, or even less. By adding a extra few pence worth of
    components, you can call them surge protected and sell them
    for 3 times the price. Brings in more profit.
    True. Even if you have millions of pounds worth of equipment
    on your supply, it isn't worth it, the occurance is so rare,
    so it certainly isn't for a few home PC's.

    What I have seen several times is damage caused by a surge
    induced by lightning on a phone line. Of course, the mains
    surge protector will do nothing to protect against that.
    Not in my opinion.
    If I saw something at less than rip-off prices for protecting
    against surge on phone line, I might consider that.
  4. St Dom

    St Dom Guest

    Is the cumulative effect of transient voltages leading to premature
    equipment failure not an issue then?
    something as simple as a desk fan switched on & off and supplied via the
    same socket as a PC can create a transient over voltage of 1kV
    Sure it will not knock the PC out but it will reduce the life of the kit.
  5. someone

    someone Guest

    I have no UK electrical power system knowledge.

    I do however have extensive electrical utility knowledge.

    I would never install a computer without a UPS.

    What is the age of the installed cables? When a cable faults the surge is
    Transformers, capacitors, breakers, generators ...all fault at times and
    they result in heavy electrical surges.

    HDD are frequently corrupted due to power events.

    ~$40 USD (350VA) with $15000 of equipment insurance is worthwhile.
  6. J.J.

    J.J. Guest

    Does anyone have a reference to HDDs getting corrupted by power
    events on the mains power supply?
  7. Soren Kuula

    Soren Kuula Guest

    The tree ? Lost or not ?

  8. Anthony

    Anthony Guest

    References, no, practical, hands on experience, yes. I've seen this
    several times, not only the HDD, but I've had transient power problems
    take out motherboards too.
    Case 1: Home computer (this one) tree fell across a main line (11kva I
    think), caused a surge prior to the stepdown transformer kicking out,
    corrupted an almost new 40 gig hdd. Fortunately, an LLF fixed it.
    Case 2: Engraving lasers at work, fed from the bus, kept killing HDD's
    and motherboards. Ultimately traced to transient voltage spikes,
    installed an AVR UPS. Failures were occuring once to twice a week, after
    the AVR UPS was installed on each machine, we have had Zero failures, in
    over a year.


    You can't 'idiot proof' anything....every time you try, they just make
    better idiots.

    Remove sp to reply via email
  9. Pyriform

    Pyriform Guest

    I have a surge protector which includes protection for the phone line,
    so that's where the ADSL modem gets plugged. Whether it would actually
    work or not is another matter of course. My complacency lies in not
    bothering to research the matter thoroughly, on the grounds that if I
    was buying snake oil, it was at least *cheap* snake oil...

    For the mains, online UPS is the proper solution, but I can't say I'm
    unduly concerned about not having one. Power provision in the UK is
    fairly reliable at the moment, although political and business
    imperatives will probably conspire to make it worse in the future.
  10. Mark

    Mark Guest

    Dunno about HDDS but I lost an Ethernet NIC (Netgear FA310TX) to a
    one-second transient just yesterday morning... Fortunately it is one
    of the cheapest and simplest parts in the PC to replace.
  11. w_tom

    w_tom Guest

    A plug-in surge protector is on the order of tens of times
    more money per protected appliance. Furthermore it does not
    even claim to protect from the typically destructive
    transient. Protectors do not stop, block, filter, or absorb
    destructive transients. Ineffective protector manufacturers
    get one to wish that is how they work. In reality, the
    protector is not protection. Protector and protection are two
    separate components of a surge protection system. Effective
    systems must include the protection. And the connection to
    protection is either a hardwire (less than 3 meters) or a
    protector (also part of a less than 3 meter connection).

    In short, the protection is called single point earth
    ground. Destructive surges may enter the building seeking
    earth ground. If not earthed (either by hardwire connection
    or by surge protector), then the destructive surge may find a
    path to earth ground via computer. One classic example is due
    to a direct strike to lines highest on utility poles - AC
    electric. Incoming on AC electric, through computer and its
    modem, then outgoing to earth ground via phone line. Many
    then *assume* the surge entered on phone line, damaged modem,
    then stopped - a violation of even primary school science.

    Effective protection means all incoming utilities are
    earthed before entering the building. All must be earthed to
    the same single point earth ground. That means even the CATV
    wire drops down to earth ground, connects ground block 'less
    than 3 meters' to that earth ground, and only then rises back
    up to enter building. Again, no surge protector required
    because earthing is accomplished by a direct and short
    hardwire connection.

    These concepts are explained further including some examples
    of 'whole house' protectors for AC mains at:
    "RJ-11 line protection?" on 30 Dec 2003 through 12 Jan 2004 in
    pdx.computing at and
    "strange problem after power surge/thunderstorm" in
    comp.dcom.modems on 31 Mar 2003 at .

    Additional information on how surge protectors work, how
    they are rated, installed, etc was posted in:
    "Opinions on Surge Protectors?" on 7 Jul 2003 in the
    newsgroup alt.certification.a-plus at and
    "Power Surge" on 29 Sept 2003 in the newsgroup
    alt.comp.hardware at

    One industry professional demonstrates how two structures
    are protected. Notice every wire entering each structure
    (building and tower) must first connect to single point
    ground. Even the buried phone wire carries a potentially
    destructive transient which is why even buried wires must
    enter building at the service entrance with the 'less than 3
    meter' connection to earth ground:

    How do we identify ineffective protectors? 1) No dedicated
    connection to earth ground AND 2) manufacturer avoids all
    discussion about earthing. A surge protector is only as
    effective as its earth ground - the protection.

    Those ineffective protector manufacturers fear you might
    learn about the essential earth ground AND discover that
    plug-in protectors cost tens of times more money per protected
  12. w_tom

    w_tom Guest

    Hard drives can be corrupted for various reasons based also
    upon what the filesystem is. For example, if using FATxx
    filesystems, then a loss of electrical power at the right time
    can even erase files from that drive. Just another reason why
    the technically informed want NTFS filesystems on drives; not

    Transients should never be a problem to disk drives or
    memory. Based upon how these devices are connected, then a
    differential type transient would be required to cause
    damage. But all minimally acceptable power supplies must have
    the essential function called overvoltage protection - that
    makes a differential transient not possible.

    That is the theory as well proven by power supplies even 30
    years ago. Reality is the gross profits obtained by dumping
    inferior supplies in North America where so many computer
    assemblers don't even have basic electrical knowledge. Many
    clones are not built and sold missing the essential
    overvoltage protection because the assembler only understands
    one specification - dollars. It's called a bean counter
    mentality. If the power supply is sold on the cheap, (ie full
    retail price is less than $60), then this and other critical
    functions are simply *forgotten*. Does not matter. Consumer
    is only to be fleeced.

    If the destructive differential transient does occur, there
    is no overvoltage protection circuit to protect that hardware
    - do to power supply purchased by a bean counter. No
    problem. Myth purveyors then quickly blame speculated surges,
    and recommend overpriced, typically undersized, and
    ineffective plug-in protectors.

    Up front - does the power supply specifically state that
    overvoltage protection is provided? If not, then it probably
    is a man-made disaster just waiting to destroy disk drive,
    data, and other computer components.

    This overvoltage protection is something completely
    different from another disk drive threat to FAT filesystems -
    blackouts and brownouts.
  13. J.J.

    J.J. Guest

    Could a very fast-acting switch (like in an Residual Current
    Detector) be used to cut the incoming power supply quickly enough
    to halt the transient mains electricity spike before it got to be
    too large?
  14. w_tom

    w_tom Guest

    Again an assumption that something will stop or block a
    destructive transient. Kilometers of air could not stop the
    transient. Do you think that silly little RCD switch contact
    will do what kilometers of sky could not? Again, protection
    is about shunting (diverting, connecting, shorting) a
    transient to earth ground. There is no way around that
    fundamental fact. Nothing is effective at stopping such

    Again, read those cited discussions. Effective protection
    was even demonstrated by Ben Franklin in 1752. It too is
    discussed there. Did Franklin stop or block transients? Of
    course not. Only products selling on myths attempt to get
    others to "speculate" that protectors work by sitting between
    the transient and its objective - earth ground destructively
    via a computer.

    Second - what fast acting switch? That RCD maybe takes 10
    milliseconds to respond. In the meantime, 300 consecutive and
    destructive transient would complete before the RCD even
    thought about tripping. That fast acting switch has the speed
    of molasses. Effective protection is defined in those
    previously cited posts. You have much to learn there.
  15. Yes, we've had an exceptionally stable/reliable supply in the UK
    for perhaps 30 years now (or well over 40 years if you ignore the
    1972 miners strike). There are a number of reasons why that's
    unlikely to be maintained in the future though.
  16. My surge protector came with a guarantee that the company will pay to
    repair or replace any equipment damaged through the powerlines when it was
    plugged in to their product.
  17. Louis Bybee

    Louis Bybee Guest

  18. Keith

    Keith Guest

    Have you collected on that promise? Somehow I think you'd buy an extended
    warranty on that strip too. ;-)
  19. J.J.

    J.J. Guest

    What sort of reasons do you have in mind for causing a less
    stable/reliable UK mains power supply?
  20. In a nutshell...
    o We are no longer self-sufficient in energy (became a natural gas
    importer last year) and are increasingly going to have to rely on
    sources from the less stable parts of the planet and sources
    which require traversing the less stable parts of the planet.
    o All the non-natural gas sources of generation are winding down
    at the end of their service lifetimes, and no more being built
    (ignoring renewables, which are currently insignificant).
    o We no longer have a store of energy -- we used to have many months
    supply of coal stockpiled at power stations and weeks supply of
    gas stored in gasometers -- all now gone.
    o We now have very little in the way of spare generating capacity.
    The nationalised electricity generating board used to maintain
    spare capacity to enable peaks and unexpected outages to be
    handled without concern, but the privatised companies mothballed
    this plant as they are only paid for what they produce. It
    would take between 3 months and a year to get it back in service,
    depending how long it's been mothballed, so it's no use as an
    energency reserve.

    The industry had a wake-up call on 10 December 2002 when the country
    got within a couple of minutes of having to load shed (switch off
    parts of the country in an emergency due to not enough power being
    able to be generated to meet demand). In spite of this, nothing was
    done. Again last winter, there was a particularly cold spell forecast
    and a number of experts warned we were in an even worse state than
    the year before. Fortunately, the cold spell wasn't anything like as
    bad as forecast. Given these wake-up calls have been ignored by the
    government, it looks like it's going to have to get worse before
    any notice is taken, and we probably are going to have to suffer a
    significant load-shedding incident blacking out significant parts of
    the country.
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