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Hardware Technology

CE Risks from Argentina's Drop to 209V? 85

stm2 asks: "Effective yesterday at 6 PM GMT, the voltage in Argentina was dropped from 220V to 209V (without any warning). The aim of this change is to save power. According to gov' officials, it won't affect domestic appliances. As a concerned IT worker I think some high precision electric devices could be at stake. There is an ongoing national debate about it. Could the technical community at Slashdot give some insights about possible unintended effects?"
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CE Risks from Argentina's Drop to 209V?

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  • by Anonymous Coward on Wednesday March 31, 2004 @01:55PM (#8726932)
    Just flip your power supply switches over to the 115V setting and you'll have more than enough power.
  • by Anonymous Coward on Wednesday March 31, 2004 @01:55PM (#8726940)
    because they are in Argentina!
  • Regulation. (Score:4, Interesting)

    by computersareevil ( 244846 ) on Wednesday March 31, 2004 @01:56PM (#8726946)
    If you have any "precision electric devices" that relies on clean power from the electric company, you have been deceived. Quality precision electronics will always provide plenty of filtering and regulation of their own.
    • Re:Regulation. (Score:3, Flamebait)

      by jungd ( 223367 ) *

      Surely, this is only true in countries where utility power is unreliable (like the US)?

      I moved to the US five years ago and was initially amazed that someone had experienced a power outage in their lifetime! - After realizing they weren't joking I though it must have been a pretty unusual circumstance - like a major earth quake or something. First time I'd ever heard of surge protectors in power strips too - yikes! - doesn't give a good feeling about the power.

      Of course, now I know better, that the elect

      • Re:Regulation. (Score:3, Informative)

        Surely, this is only true in countries where utility power is unreliable (like the US)?

        No, truly precision devices (by that I mean measurement instrumentation) can not rely on the powerline voltage remaining within 0.1% of spec as a cheap, off the shelf voltage reference chip can.

        In short, I guess I'm suggesting that assuming that all electric devices are built to handle unreliable power (brownouts, spikes etc.) is perhaps country specifc.)?

        I sure hope not. Would be pretty poor practice on the part

        • Refrigerator or A/C compressor switches on == big dip in line voltage

          Word. Somebody plugged in an air purifier or something like that in the same power strip my computer is plugged in.

          Turning on the damn shit reboots my computer. I didn't notice until today, as people usually turned it on when I was out.

      • Re:Regulation. (Score:5, Informative)

        by foooo ( 634898 ) on Wednesday March 31, 2004 @05:25PM (#8729562) Journal
        No need to be an such an ass to your "host" country. Most problems of this nature in the US are due to having a much larger land mass. Additionally populations (on average) in the US are much less dense than their northern european counterparts making it much harder to support infrastructure of this kind.

        US power companies are regulated... but they don't have the advantages of government run power companies. IE they can't just dip in to the general fund if the feel like they want to make some infrastructure improvements. They actually have to justify it.

        I live in a reasonably dense area and my power goes out maybe once every two years. When I lived out in a more rural area my power went out several times a year... the further out you are the less dense the population and the more likely your power will go out.

        Astoundingly Americans have learned to deal with it. Frankly it's not worth it to me to pay more to have more reliable electricity. If I want more security I'll make sure I have my own means of power production or UPSes or something.

        I would be interested to know the "real" per capita expenditures for electricity in your previous country. I'd also be interested to know the "real" per kilowatt hour price. These numbers would have to include government subsidies.

        I think there are some government subsidies for power companies in the US but I would assume (I'm not certian) that they are lower than your previous country of residence.

        As for doing your own wiring while you can certianly hire electricians in the US and many new construction projects require inspection from an electrician before permits are approved/issued.

        Frankly I'm shocked that other countries wouldn't allow citizens to do their own wiring. Not only is it a freedom issue but a phenomenal waste of money to always have to pay someone else to do work that just about anyone could do.

        Additionally European electronics certifications are much more stringent than those in the US. So even if the power is more reliable the government will make darn sure the end user devices are still very robust... and therefore they should cost as much or more than their US counterparts.

        I can't really speak for Japan or other Asian/African nations since I just don't know very much about their electrical systems.

      • Re:Regulation. (Score:1, Insightful)

        by Anonymous Coward
        I moved to the US five years ago and was initially amazed that someone had experienced a power outage in their lifetime!

        Man, you're an idiot (or a troll). Did you hear about the large power outage not long ago which took out most of Italy?

        I've even done some re-writing of light fixtures in our house myself - no degree/license required!

        Good for you. Not everyone requires the use of a licensed electrician to change light bulbs.
      • First time I'd ever heard of surge protectors in power strips too - yikes!

        From previous posts, you're from somewhere in the UK.

        None of the UK has weather like the SE USA does (yes, I've lived in both places... although I was very, very young when I lived in the UK). We have far more thunderstorms and tornados than just about anywhere else on the planet. Add to that extremely hard clay soil and (more recently) insect populations that consider insulation jackets to be good food and it's extremely hard to s
        • > From previous posts, you're from somewhere in the UK.

          Unlikey, as:

          1) We get power cuts due to the weather over here too (though they don't tend to last very long, but as you pointed out the weather isn't as extreme).

          2) You can rewire you house yourself if you like.

          3) Surge protectors are easily available - but not used very much.
        • Re:Regulation. (Score:3, Interesting)

          None of the UK has weather like the SE USA does (yes, I've lived in both places... although I was very, very young when I lived in the UK). We have far more thunderstorms and tornados than just about anywhere else on the planet.

          Interestingly, Britain is, according to a survey I can't find right now, the place in the world with the largest number of reported tornados for its size. Of course, there are tornados and there are tornados, and it's relatively rare for what passes in Britain as one to be destruc

      • Wars are like a natural wildfire. They devaste, but make room for new growth without hinderance on the past.

        Much of Europe and large parts of England were obliterated during WW2. The eletrical infrastructre was all but removed totally. They got the chance to rebuild from the ground up, having the knowledge of what didn't work out so well before.

        Contrast this with America, we have lots and lots of very old power systems in place. Yeah, one day maybe we'll get lucky and lose 80% of it, but until then were s
      • That's some serious flame bait you're kicking out there. I'll bite...

        I currently live in one of those extravagantly wonderful semi-socialist countries that you oh-so loved back in the day (and yes, I am an American). Nice place, been here for 6 years. Seen a lot. Final Analysis? It's good to be an American overseas.

        Since I've been here I've gone through brownouts galore, stuck living on a breaker that provides enough power for two high amp devices (Coffee Pot and Toaster), and now have the foresight
        • It's all nice, and said with passion, but what a political rant of some ignorant American has to do with American power grid quality?
      • Try rural New Zealand. In a Canterbury Nor'wester it's not uncommon for a tree to fall on a power line. In gale force nor'westers I've even heard of those big steel pylons to bend & crumple. Parts of New Zealand are even more sparsely populated than the USA (4 million people in a country of similar size to the state of California).
        No-one in NZ would run a mission-critical server without an UPS.
        As for voltage fluctuations - better have a good filter too.
  • AC Motors (Score:4, Interesting)

    by Detritus ( 11846 ) on Wednesday March 31, 2004 @01:58PM (#8726962) Homepage
    I thought that the main risk during power brown-outs was damage to AC motors from overheating. At least that's what they have mentioned on local radio stations when we've had power shortages.
    • yeah, because it passes current through the coils and the troughs of AC sap just enough energy to not spin the motor...turning it into a giant heater. Anything that hums needs to be unplugged...
  • Back to 220 (Score:5, Informative)

    by crow ( 16139 ) on Wednesday March 31, 2004 @01:58PM (#8726965) Homepage Journal
    A quick check at Google News revealed: sid=a54gb5_g9EIQ&refer=latin_america []

    Apparently they've put the voltage back to 220 after reaching an agreement to buy power from Brazil.

  • by MerlynEmrys67 ( 583469 ) on Wednesday March 31, 2004 @02:07PM (#8727057)
    I would figure your device needs 440W. At 220V you pull 2A to get that. You drop the Voltage to 205V and your device now pulls just under 2.15A.

    I guess in a micro scale it doesn't save electricity - but in a macro scale several devices don't let more than X Amps go through before popping a circuit breaker, therefor the devices are pulling a constant amperage and saves power.

    On a side note - I thought I remembered that the higher the voltage, the more efficient the transmission line, however I know that works for DC (If I recall TVA uses something like 50K Volt DC lines to ship power around) don't know about AC power.

    • I'd be greatly surprised if power lines were transmitting DC. One of the main, historical advantages of AC is that it is much, much easier to transform voltage up and down, making transmission viable.
      • I seem to have goofed by an order of magnitude on the transmission voltage. From TVA [] Seems the lines are 500KVolt... Still haven't confirmed/denied AC vs. DC
      • Local power in the US is sent via High Voltage AC. Very few connections in the US are DC - but there is at least one I know of. The Northwest Intertie used to ship power between Washington state and Southern CA uses a High Voltage DC. There is a simple physical reason why - it is about a 1500 mile trip, i.e. roughly 1/4 wavelength at 60Hz. They went DC because of that little feature.

        The southern terminus of the transmission facility is visible off of I5 as you enter LA from the North.
      • DC transmission lines are actually more efficient than AC; AC only rides on the "skin" of the conductor (google for skin effect) whereas DC travels through the entire conductor, leading to higher IR losses, among other things.

        The problem is, as you've mentioned, adjusting the voltage easily. However there are plenty of HVDC links and they're used for a variety of purposes. Among them is connecting unsynchronized grids and higher efficiency "bulk" power transfers.

        I wrote extensively on this on Kuro5hi

    • Ohms law basics (Score:5, Informative)

      by Tor ( 2685 ) on Wednesday March 31, 2004 @02:31PM (#8727323) Homepage
      I would figure your device needs 440W. At 220V you pull 2A to get that. You drop the Voltage to 205V and your device now pulls just under 2.15A.

      In a simple device, the resistance is roughly constant (up to a certain point). When you decrease voltage, then the current draw actually decrease as well, thereby reducing the power consumption to the 2nd degree.

      In your example, a device that draws 440W at 220V (i.e. 2.0A) has a resistance of 0.5 ohms. When you lower the voltage to 109V, that yields

      (209V/220V)*2.0A = 1.9A
      209V*1.9A = 397W

      (Ignoring the fact that 1VA is not quite the same as 1W, due to inductance/capacitance).

      • A potential of 220V over a resistance of 0.5 ohm would produce a current of 440A, dissipating 96kW.

        During my MSEE studies we were installing some lighting equipment for a show. A fellow student made the following 'insightful' comment about the kind of electrical connection we would need: "WOW ! 15 amps and 3000 watts ! What an unbelievable voltage !". My sober reply was: "I hope for you it's 220V.".
        • I've done some professional theatre work. The sums get large fast. In an arts centre where I've worked, the power mains running from the street to the dimmer vaults are encased in concrete. There are three theatres in the whole facility each with their own dimmer vault. Combined, there are over 500 2.4kw dimmers for a theoricial load of over 12 million watts.

          In reality, it would never be loaded more that 40% of that, but still, it's a large number.

        • A potential of 220V over a resistance of 0.5 ohm would produce a current of 440A, dissipating 96kW.

          Yeah, sorry.

          On the bright side, the errors in my ways got modded up 2 points on Slashdot! I guess you can't really have an uncritical mind around here... :)

    • by Aniquel ( 151133 ) on Wednesday March 31, 2004 @02:35PM (#8727352)
      Hm, IIRC, don't think it works like that. You're assuming that a device draws enough current to meet power requirements (P = VI). However, in this case V is fixed, and I is determined by resistance (R). Remember V = IR? So, the effect of fixing V at a lower value is: 1) I goes down according to V = IR, and 2) P goes down because of the new (lower) I in addition to the lower fixed V, according to P = VI.
      • It doesnt apply to regulated power supplies, because they lower their internal resistance to provide a fixed output voltage.
      • Induction motors are one good example. An induction motor's speed is determined mostly by the drive frequency, not the applied voltage. Lowering the voltage can affect the slip between the rotor and the stator field, which in turn affects things like the magnetizing current draw. If the voltage drops too low the stator field cannot transmit enough torque to keep the slip below the torque peak, and the motor stalls; a stalled motor has no cooling unless it has an external cooling mechanism, so it can overhea
    • On a side note - I thought I remembered that the higher the voltage, the more efficient the transmission line, however I know that works for DC (If I recall TVA uses something like 50K Volt DC lines to ship power around) don't know about AC power.

      If I remember correctly, one of the reasons that the world went with AC over DC was because you can change the voltage of AC without interrupting the transmission. You can pump up the voltage to overcome the initial impedence of the lines and then reduce the volt
    • No, electricity cables operate at very high currents. Here's why:

      P = IV


      V = IR


      P = I(IR) = I^2R

      Therefore, by transmitting at a high current you lessen the amount of power that you lose to resistance. So simple I learnt it in school.
      • If I'm not mistaken, P = I^2R is a measure of the energy dissipated (as heat) as a current passes through the conductor.

        Thus, you want transmit power at high voltages and low currents.
        • Doh! You're right, the voltage figures are a lot higher (up to 400 kV) than the current values (up to 4,000 A) but I'm fairly certain that you want a high current for the reasons that I previously stated.

          If the current is too low then you're not transmitting as much energy (power) as you'd like, and a far higher proportion of it is lost between the transmission and reception points.

          (Of course, I learnt this stuff two decades ago, so it's entirely possible that I've got it wrong because my brain's turned t
        • I assure you that you're wrong :) I^2R is the power lost at heat. It's not the current that makes the power lines arc, it's the extreme voltage potentials.
    • It's amazing how many people don't know that power *IS* transmitted using DC and AC lines now days. Transformer advances have made possible very efficient DC transformers, and super high voltage DC lines have been built. Im sure you could Google the concept and find out more. :)
  • The funny thing here is that all appliances that regulate the amount of power they consume will continue to consume the same amount of power, but the decreased voltage will cause more power to disappear on the way to the transformers.
    • Re:"Save power"? (Score:5, Informative)

      by Mr. Slippery ( 47854 ) <tms AT infamous DOT net> on Wednesday March 31, 2004 @03:03PM (#8727655) Homepage
      The funny thing here is that all appliances that regulate the amount of power they consume will continue to consume the same amount of power

      True, but other devices act more like simple resistors, and if less voltage is applied they will consume less power. You PC will self-regulate, but your lightbulbs will get dimmer.

      I'll bet that light bulbs and other "simple resistor" devices outweigh PCs and self-regulators several times over.

      • Just wait for the self-regulating 100 watt light bulb. What would be bad is that it would sell. Consumers would want a 100 watt bulb rather than a 5-10 watt bulb that puts out the same about of light.

        One day I'm going to switch light bulbs myself.
  • by DeepBlueDiver ( 166057 ) on Wednesday March 31, 2004 @02:11PM (#8727104)
    As almost anything you have seen on the news from Argentina, reality is quite different.

    Electricty companies have been demanding an price increment since 2 years ago, but it would be a very unpopular and "politicaly incorrect" for the government to allow it; so they need to present this as some kind of "emergency".

    In the end, companies will:

    a) be permited to rise prices about 25%
    b) receive a direct subside from government
    c) receive an indirect subside form government in form of tax excemptions, "special" fuell prices for generation, "loans" for equipment renewal, etc.
    d) all of the above
    • If power producers are making so much money, you'd think outside investors would be funding the building of more plants, so that they can get a piece of that big pie.

      But they are not. So, why are they holding back?

      • but it sounds like the Argentina gub'mint has price caps that prevent the producers from reaping the true value opportunity of the power market. The price caps to ensure "cheap" power are CREATING power shortage! Higher prices (or lawsuits) are sure to follow.
        • We had/have a similar problem here in the California Republic, and solved it by destabilizing our leftist government and letting a semi-rightist austrian strongman rise to power in a popular coup.

          Well, perhaps not solved the problem, but when the power goes out this summer, we can intimidate our neighbors and have them send us power so that we don't come in an take it--I mean, have you seen that guy's biceps?
    • my god, I have to take a slashdot multiple guess test...damn.

      Oh well, I choose to bubble in each choice lightly and let the scantron machine go FARK! instead.

  • problem solved! (Score:3, Informative)

    by LordAlpha ( 247426 ) on Wednesday March 31, 2004 @02:23PM (#8727236)
    Already solved [] with help from Brazil, Bolivia and Venezuela.
  • by stienman ( 51024 ) <adavis AT ubasics DOT com> on Wednesday March 31, 2004 @02:27PM (#8727292) Homepage Journal
    Good engineering design requires at least 5% tolerance for voltage differences. That's 11 volts at 220, and 209 should be well within the range of all line powered equipment. You simply can't design a product and expect the voltage to be within 5% regulated value.

    Most equipment will run just fine with only 10-20% regulation. The problem with dropping the voltage is that the lower limit is much closer. A 10% device can handle voltages between 198 and 242, but if the utility lowers the voltage to 209, then when it's low by 10% it's at 188v, outside the range of a device capable of operating within 10% of its spec.

    The reality is that most electronic devices use transformers and switching regulators to convert line voltage to a much lower voltage. As long as the device isn't consuming its maximum rated current (which will usually be 95% of the time) then it should be fine. The 5% of the time the device is actually using the regulator to its maximum capacity the regulator may fail to provide the voltage level. This erratic behavior will be about the worst you can expect. In most cases you won't even notice this.

    The last major effect such a decrease may cause would be to large industrial motors. They are also often specified with a voltage range at which they can provide their rated HP. Lower voltage means a lower output. Those that are specified tightly, or have dodgy starting controls/capacitors may fail to start, but that's an indication of improper sizing/usage and not something that should be blamed on the power company. Of course, at a lower voltage they simply will not perform at the level they do with full voltage, but that is the stated goal for the gov't - to reduce power.

    The negative effect for the gov't, though, is the result that people who want or need the same amount of power will simply be pulling more current (amps), stressing out the grid and transformers even more. This will affect transformers and lines that are already operating at their limit, or are about to fail anyway. It's unlikely, though entirely possible, for this action to cost them more than they are saving in the long run.

  • by DeepBlueDiver ( 166057 ) on Wednesday March 31, 2004 @02:35PM (#8727354)
    My tester shows 213 V right now, at my house in downtown Buenos Aires. As I said in a previous post, this is just PR bs.
  • by ElectricRook ( 264648 ) on Wednesday March 31, 2004 @02:36PM (#8727360)
    Switching mode power supplies take the very large raw input voltage, and draw directly from that input for only a very short time (micro seconds), but several thousand times a second (80Khz). The switch adjusts it draw time to collect the amount of power needed to support the output. If the input voltage drops, the switch adjusts to accept power for a slightly longer time. Really good switching power supplies (not like your PC) will operate on input ranging from DC to several hundred hertz.
    • I could be completely wrong, but in physics class, I seem to remember doing an experiment, to indicate the frequency of the power coming out of the wall was 60Hz.
      • It is... and in some countries it is 50hz. The switching power supply has four really big transistors and they switch at about 60-80kHz. Each time the transistors switch on or off, they don't care where in the cycle of input power they are. They turn on for just a few micro seconds, then turn off. The power supply gets what ever power it gets in this time frame. The "chopper" which is the heart and soul of the power supply has that "on" interval constantly changing to keep the power level constant. If
  • Our building 220vac supply actually reads 208vac here right now, so I really don't think 209vac is such a big deal. Most devices have a pretty good tolerance for lower than "adveritzed" voltages.

  • Germany: 220V - 230V (Score:4, Interesting)

    by Tux2000 ( 523259 ) <alexander&slashdot,foken,de> on Wednesday March 31, 2004 @03:07PM (#8727702) Homepage Journal

    Some time ago, voltage was switched from 220V to 230V in Germany (and thus 380V to 400V for three phase current). There was a lot of arguing and lamenting, but nothing interesting happened. Most consumer electr(on)ic devices were rated 220V +/- 10%, while the power authorities guaranteed 220V +/- 5%. Now, devices are rated 230V +/- 10% and power is 230V +/- 5%. So most devices work within their specification, no matter if it is based on 220V or 230V. Some light bulbs rated 220V will light a tiny bit brighter while reducing ther lifetime by a few days.

    I don't know how precise Argentina's power authorities can deliver electric power, but I guess they specify it with +/- 5%. They reduced power by exactly 5%, it should not harm most consumer electr(on)ic devices. All heating devices should have no problems, they work with slightly reduced power. Most electronic devices use voltage regulators, so they can accept a wide range of input voltage. Some few devices may need a very precise AC input voltage, but they should already work with some regulation device. The remainder could use an active UPS that generates a very precise output voltage no matter how "ugly" the input voltage is. Wide range power supplies, as used with many modern laptops, accept any input voltage between 90V and 260V, as long as it is AC. They won't have any problems with 230V, 209 V, 135V, 188V, or whatever you find at the next power outlet.

    And the best of all: Light bulbs will life longer in Argentina. ;-)


    • In UK, when EU voltages were 'harmonised', the normal supply at 240v was already within the permitted range, so only the nominal voltage was changed to 230v, the actual supply voltage remained at 240v. See this article [] for more details and potential problems of this approach.
    • The voltage change in Germany was to comply with EU rules. At the same time the UK went form 240v to 230v, I was studying EE at the time and my industrial mentors told me that their suppliers had changed the tolerance on their equipment so that it would work between 210v and 250v over the previous years to deal with this as most countries generators struggle to keep in a 5% tolerance anyway.

      However as mentioned above heavy industry will have problems. I believe but I am trying to remember from a sixth fo
    • I was who made the question. I knew that standart consumer devices would be just fine, my question was about high precision devices like:
      Capilatiry DNA Sequencer (ABI brand).
      High precision scales for analitical use (for drug weight).
      PCR machines and other laboratory equipment.
      Anyway, seems to be back normal now, but in this country (Argentina) you don't know what is going to happend, so maybe we run out of power and have to reduce it again!. I think it is time to buy better UPS.
      • my question was about high precision devices like: Capilatiry DNA Sequencer (ABI brand). High precision scales for analitical use (for drug weight). PCR machines and other laboratory equipment.

        I just guess that this lab equipment is "digital", i.e. it uses mostly microprocessors and perhaps a little bit of mechanic. So, it is very likely that these devices have a regulated power supply that should work with a little bit less AC input.

        You may want to ask the vendor or manufaturer of the devices if any of t

  • I seem to think that good-quality uninteruptible power supplies have some electronic wizardry in them to correct for input voltage. I.e., a UPS would output 110 or 220 volts regardless whether the input voltage is off. Can anyone corroberate this?
  • Dropping the voltage by 5% does not reduce it to the point where it is out of the standard specification -- at least, not theoretically. Spec allows for as much as 10% variation.

    This may, however, cause problems for customers at the end of long distribution lines whose voltages are already below 220. If it is continued indefinitely, it may cause further problems as more customers subscribe and there's less play left in the system.
  • You do have a UPS that corrects for this, right? []

    And your computer power supplies are up to the task []?

    If not, I would start buying ASAP...

  • by Kanasta ( 70274 )
    Wouldn't devices just draw more current to run, or run less efficiently?
  • As previous posts quite rightly say, the impurities of the mains supply will always be filtered out to the degree demanded of the electronic equipments spec. As for CE, These are the european version of the FCC rules. Again, well designed equipment will 'filter' out variations in the power supply I doubt it will make any difference to the amount of interference generated by electrical and electronic devices. Conversly I doubt their susceptibility will alter either. Now if they had changed the frequency of

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