110 volt vs 220 volt<<emergency,please help

[AM.1990]

Hi guys.I want to know which 110 or 220 voltage is better.why some countries such as U.S use 110 and many others use 220?which is more safe?which is harder to produce?and which costs more?
any comments and helps will be appreciated.Thanks

 

[sparky steve]

This is an interesting question, I am sure that the 110V issue is as someone else says historical, Europe runs 220-230 VAC Here in Western Australia we run 240 however it depends where you are I have seen it past 250V AC on a true RMS meter and European light bulbs which are nominally 230 are a tad bright and don't last too long! In theory the 110 volts should be safer, but as has been pointed out either will hurt and it is ill advised to attach yourself to any supply unless you wish to become toast. As for the 110 volts on building sites that comes from a centre tapped transformer and the centre tap is earthed, so it becomes a 55 0 55 transformer with each leg being 55 volts with reference to earth, that will also hurt but is a lot safer than anything else. As someone pointed out in the US they do use two of the three phases at 110 per phase to get a higher voltage which by my math would be 190 volts and not 220 as some would think. Also historical is the 50 and 60 Hz business which really only serves to stuff clocks and motor speeds! These days I could debate the whole safety issue especially with regard to the 110 volt transformers on building sites RCCD protection to a large extent negates that with the only thing being it has to be installed and tested to ensure it is working. Certainly here in W.A we run 240 volts on building sites without too much of an issue. Also these days more and more equipment has the tiny switch mode power supplies who run 90 to 250 volts AC once again making the voltage no longer an issue.
Obviously the big world wide issue is colour coding of cables which is not standard and waiting for the unwary to bite them, I just love the idea of using black and white for example which is common in America and Japan the only difference being which one is the live one!
Sparky Steve

 

[AM.1990]

This is an interesting question, I am sure that the 110V issue is as someone else says historical, Europe runs 220-230 VAC Here in Western Australia we run 240 however it depends where you are I have seen it past 250V AC on a true RMS meter and European light bulbs which are nominally 230 are a tad bright and don't last too long! In theory the 110 volts should be safer, but as has been pointed out either will hurt and it is ill advised to attach yourself to any supply unless you wish to become toast. As for the 110 volts on building sites that comes from a centre tapped transformer and the centre tap is earthed, so it becomes a 55 0 55 transformer with each leg being 55 volts with reference to earth, that will also hurt but is a lot safer than anything else. As someone pointed out in the US they do use two of the three phases at 110 per phase to get a higher voltage which by my math would be 190 volts and not 220 as some would think. Also historical is the 50 and 60 Hz business which really only serves to stuff clocks and motor speeds! These days I could debate the whole safety issue especially with regard to the 110 volt transformers on building sites RCCD protection to a large extent negates that with the only thing being it has to be installed and tested to ensure it is working. Certainly here in W.A we run 240 volts on building sites without too much of an issue. Also these days more and more equipment has the tiny switch mode power supplies who run 90 to 250 volts AC once again making the voltage no longer an issue.
Obviously the big world wide issue is colour coding of cables which is not standard and waiting for the unwary to bite them, I just love the idea of using black and white for example which is common in America and Japan the only difference being which one is the live one!
Sparky Steve

Interesting,i searched about the history and i found this:::

"It's interesting how we came to have our current mess of global voltage standards - a problem which every traveler deals with on a recurring basis. Nicola Tesla did some great empirical work in the 1860s to determine that 220vac at 60Hz was the optimal combination (at least for motors, which were the key to having an electricity business in the late 19th century) but Edison forced 110vac on the US because that's what his DC generators on Pearl Street in NYC ran at."

and europe which is metric wanted 50hz instead of 60hz, but because electric motors are less efficient at that frequency they had to up the voltage to 240v
paraphrasing from his web site the author of this article Chris Westland goes on to say:


"Tesla was considered the reigning authority on alternating current in that day (Edison was promoting direct current systems, thinking AC too dangerous for commercial use). When air brake tycoon George Westinghouse invested in AC distribution systems, which could bridge the distance between his generators in Niagra Falls and his markets in New York City because of their low line losses, he consulted Nicola Tesla on developing a motor (a key part of the whole system, just as the light bulb was the key component in Edison's systems). Tesla made many careful calculations and measurements and found out that 60 Hz (Hertz, cycles per second) was the best frequency for alternating current (AC) power generating. He preferred 240 volts, which put him at odds with Thomas Edison, whose direct current (DC) systems were 110 volts. Perhaps Edison had a useful point in the safety factor of the lower voltage, but DC couldn't provide the power to a distance that AC could.

Tesla built Westinghouse a prototype motor, optimized for 60 Hz and 240 volts AC. Westinghouse's original system ran at 133 Hz, and not surprisingly, Tesla's motors failed to put out any power at that frequency. Westinghouse's own engineers tried to redesign the motor (Tesla would have nothing to do with redesign, insisting that Westinghouse change his generating network to 60 Hz and 240 volts). The rest is history, as Westinghouse gave in to Tesla (and more importantly, the laws of physics) and changed is grid to 60 Hz - our standard today. Thomas Edison, the largest player in the electrification business in the US, initially conducted smear campaigns against Westinghouse's system (he even coined the term 'Westinghousing' for execution of criminals in the electric chair) arguing that alternating current was too dangerous for domestic use, sometimes accompanied by garish public electrocutions of stray dogs just to demonstrate. But Edison ultimately came to believe in the superiority of AC, and switched his 110 volt DC systems over 110 volt AC systems, which is where we get our US standard of 60 Hz and 110 volts AC....'

"...In the rebuilding of Europe after the war, companies had an opportunity to rethink the design of electrical distribution from the ground up. Unfortunately, they ignored Tesla.
When the German company AEG built the first European generating facility, its engineers decided to fix the frequency at 50 Hz, because the number 60 didn't fit the metric standard unit sequence (1,2,5). At that time, AEG had a virtual monopoly and their standard spread to the rest of the continent. In Britain, differing frequencies proliferated, and only after World War II the 50-cycle standard was established."
(Source:Yahoo answers about whats the difference between110v and 220)

 

[sparky steve]

The frequency issue is interesting because Tesla was correct if ahead of himself, Aircraft run 400Hz because it uses less iron in the inductors and transformers so less weight, where I work we have a HF generator which converts 50 Hz to I think 400 to run a bunch of grinders and polishers because the units are so much more powerful for their size compared to 50 Hz versions and when you are polishing all day that is important. So 60 or 50 are flawed but the technology was inadequate at the time for anything higher, equally an 2 pole alternator is running at 3000RPM to produce 50 HZ or 3600 for 60 HZ so anything higher requires more poles and faster RPM. Switchmode supplies run above 25Khz which is why they are tiny, however above 400Hz you get into strange territory due to such things as skin effect.
Sparky Steve

 

[dragon-av]

110v would normally be considered safer than 220v which is why 110v is the prefered standard for power tools on sites. 110v is much less likely to kill you, should you feel the need to touch live cables.

110V for site is not the same as US 110V Site is 55V+ to 55V- centre tapped earth not 0-110V using 110 means you have twice the current than 220V.

 

[boatnik1]

110V for site is not the same as US 110V Site is 55V+ to 55V- centre tapped earth not 0-110V using 110 means you have twice the current than 220V.

Yep. That's what I thought too until I opened one up and found only a single 220v winding centre tapped to two 110v sockets.. Both types exist.

 

[sparky steve]

Whilst a 220 volt centre tapped transformer is not within the whole idea of the original 110 VAC site transformer it should still be a safety device in that the supply is now 110 volts isolated from earth and this is what gives the safety factor and is the same as a shaver socket in the bathroom, as long as the transformer is a true dual winding unit. I once found a dentists chair where the light was low voltage but built into the chair was a massive auto transformer to power it! (scary stuff) However I digress, I do wonder if the regs have something to say about site transformers?