CE Risks from Argentina's Drop to 209V?

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?"

Comments

No problem at all.

[Anonymous Coward]

Just flip your power supply switches over to the 115V setting and you'll have more than enough power.

Many wanted to reply, but couldn't...

[Anonymous Coward]

because they are in Argentina!

Regulation.

[computersareevil]

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.

[foooo]

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.

~foooo

Back to 220

[crow]

A quick check at Google News revealed:

http://quote.bloomberg.com/apps/news?pid=10000086& sid=a54gb5_g9EIQ&refer=latin_america

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

Just PR bullshit to rise prices

[DeepBlueDiver]

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

Good engineering design...

[stienman]

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.

-Adam

Ohms law basics

[Tor]

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

and

209V*1.9A = 397W

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

I read 213 V right now

[DeepBlueDiver]

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.

Re:I read 213 V right now

[TBone]

That's funny, my improvised fork testing device shows....*BZZZZZZZT*

Re:"Save power"?

[Mr. Slippery]

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.