240 AC Australia vs. 120 in USA - Page 1
Forum section: electronics / beginners

author: W8LV
author_rank: Regular Contributor
timestamp: October 22, 2013, 11:16:41 pm
content: My question is does anyone know the actual reason why 24O VAC is used some places and 120 VAC in others? How did that come to be? How did they settle on one or the other? Or 50 vs. 60 cycles for that matter? I have heard that 60 is better for lights to reduce flicker and 50 is better for motors. I just wondered..Best Regards from W8LV in Pickaway County, Ohio, USA.

author: Nerull
author_rank: Frequent Contributor
timestamp: October 22, 2013, 11:42:53 pm
content: Higher voltages reduce distribution costs and current requirements, but the carbon filament lamps of the late 1800s only work up to 100V without burning out the filament, so most of the world used around 110 (to account for voltage drop). When metal filament light bulbs became common by 1899, Berliner Elektrizitäts-Werke made the switch to 220V, as the savings made up for the costs of replacing customer equipment. Other power companies eventually followed. Other places were too entrenched and did not switch, with the US being the main one.50/60Hz mainly comes down to Westinghouse deciding on 60Hz and Germany settling on 50Hz. Why each was chosen, I'm not sure.

author: Stonent
author_rank: Super Contributor
timestamp: October 22, 2013, 11:45:12 pm
content: EDIT: Someone else beat me to the post, but I'll leave mine as-is, some may be wrong.A lot of it has to do with the wiring. 120V in the US is designed around wiring that can support a higher current. I think that in other parts of the world, the wiring (initially) was not suitable for that level of current so the voltage was raised to keep the wattage the same.And the 50/60 thing had to do with whatever the companies had. At the time all of this was designed consumers were using lightbulbs that didn't care about frequencies. Motors and some other electronics cared but most people just had lights.In Japan they used a split system of 50 and 60 depending on the part of the country. I think that some of that has a legacy dating back to WWII when they were allied with Germany they used 50 to be interoperable but after WWII when the US was rebuilding the country, we were supplying the equipment which was 60Hz rated.

author: Smokey
author_rank: Super Contributor
timestamp: October 23, 2013, 01:17:03 am
content: Residential services in the USA usually come into the box as 220V line to line. It's just pulled to all the outlets as 110V line to neutral. Big appliances like ovens and hot tubs usually run off the full 220V.

author: GeoffS
author_rank: Unknown
timestamp: October 23, 2013, 02:19:09 am
content: When electricity was introduced, it's main function was for lighting. The only available light bulbs were carbon filament which were best suited to 100V.When metal filament lamps that could take a higher voltage were introduced, electricity providers moved to 250V to take advantage of the more efficient distribution it offered.

author: IanB
author_rank: Super Contributor
timestamp: October 23, 2013, 03:23:18 am
content: Quote from: Smokey on October 23, 2013, 01:17:03 amMost of the time you will find a standard voltage of 240 V/120 V especially in a city or modern development. But if you are in an older property or far from the transformer you may find the voltage drops to 110 V.

author: ddavidebor
author_rank: Super Contributor
timestamp: October 23, 2013, 05:17:58 am
content: 50hz is because if you increase the frequency the line loss is too high, if you decrease it the transformers become too big and expensive.Is a compromise.On train, where you don't have long lines but weighgt is important, they use 400hz

author: amyk
author_rank: Super Contributor
timestamp: October 23, 2013, 05:47:46 am
content: Quote from: ddavidebor on October 23, 2013, 05:17:58 amYou mean planes?

author: Circlotron
author_rank: Super Contributor
timestamp: October 23, 2013, 07:08:32 am
content: I think England chose 240V because they have an almost superstitious fascination with the number twenty-four. Back in those days Australia was incapable of thinking for itself (BBC London has 2LO so Melbourne Australia in a burst of originality has 3LO etc etc) so we followed suit. My house is unusual in that it has 3 x 240V plus neutral, = 415V between phases. 99% of houses only have a single phase. Out in the street there is 4 wires and the distribution tranny has a star secondary with the neutral earthed at the tranny pole base and at every consumer's house. Phases are divided among every third house if you know what I mean.

author: metalphreak
author_rank: Frequent Contributor
timestamp: October 23, 2013, 12:28:37 pm
content: Quote from: Smokey on October 23, 2013, 01:17:03 amDoesn't the USA use split phase in most places? As in, two phases, which are 240V line to line, but 120v to neutral (and both are in phase). I've never really read up on how you guys get 240V supplies.In Australia, it's all 3phase 415V line to line, which is 240V line to neutral. Each phase 120deg apart.

author: Tepe
author_rank: Frequent Contributor
timestamp: October 23, 2013, 12:36:56 pm
content: Quote from: Circlotron on October 23, 2013, 07:08:32 amHere three phase 400 V (which used to be called 380 V) is very common.Using plugs like this:

author: Monkeh
author_rank: Super Contributor
timestamp: October 23, 2013, 12:50:30 pm
content: Aurgh, kill it with fire.

author: rexxar
author_rank: Frequent Contributor
timestamp: October 23, 2013, 01:19:24 pm
content: Quote from: metalphreak on October 23, 2013, 12:28:37 pmBasically, the local transformer is center-tapped 240V. You tie the center tap to neutral (and ground) and you've got two 120V lines. They're also 180 degrees out of phase

author: ResR
author_rank: Regular Contributor
timestamp: October 23, 2013, 05:31:19 pm
content: We have two systems, one is legacy from pre-world-war-2 era and another is more modern. Pre-war system was introduced by Siemens(?) and uses 3 phases in triangle configuration without neutral and ground. Phase-to phase voltage is 220V and this system is still in use in "Vanalinn" district of Tallinn, where rebuilding is too costly. The pros for this sytem was that if you happened to touch one of the energized wires, you didn't get shocked, only if you touch 2 wires you get shocked. Of course you needed two fuses for every socket and two pole switch for lights and testing it with one contact neon indicator is impossible. Another system is 3-phase system with neutral and earth tied to ground from many locations. This system had two voltages, before the soviet collapse it was 220V between phase and neutral and 380V between two phases, soon after the collapse of the soviet union it was changed to 230V between phase and neutral and 400V between two phases. Substation transformer usually feeds multiple households, reaching to hundreds in urban area, only 3-phase transformers are used, lifetime is estimated for 50 years, but older transformers may be still in use. Transformers power range from 30kVA to 400kVA and is feed with 3 phase 10kV (+/- 2kV, regulated on transformer with 5 step switch after installation) without neutral. Multiple 10kV power lines are feeded by larger transformer that converts the voltage from 3-phase 110kV.50Hz is a frequency used.

author: G7PSK
author_rank: Super Contributor
timestamp: October 23, 2013, 05:34:24 pm
content: The US uses 110, 120 volts due to carbon filament lamps running best at around 100 volts electric lighting was adopted faster in the US so far more homes were already wired for lights by the time tungsten lamps were introduced. Europe was not so fast in installing electric lights and of course the 1914 war destroyed a lot of infrastructure so after the war rebuilding took place so the new standards were introduced.%0 HZ was down to Parsons, he made his steam turbines to run at 1500 RPM so a 4 pole alternator gives 50HZ it was not the 50HZ he was after but that was the best speed for his turbines at that time. In the US many town supplies were generated by petrol/gasoline engines and 1800 rpm was a good speed for those and gas engines which were also used ran best at a slow speed and so 900 rpm was chosen as a common speed but 60 HZ was not the standard 25,45 and other frequency was also used it was the building of the Niagara power plant that set the frequency for the US when New York adopted 60HZ.

author: Neilm
author_rank: Super Contributor
timestamp: October 23, 2013, 05:52:48 pm
content: Quote from: Circlotron on October 23, 2013, 07:08:32 amBefore the UK became standardised on 240V, there were different voltages and plugs in almost every town in the country. With some being AC at 50Hz, some AC at 60Hz. I believe there were even places that had distributed DC.400Hz is used in some applications that are I believe that are weight important (ships, vehicles) as I believe it causes problems transmitting it over long distances. I think the railways use 16Hz.

author: IanB
author_rank: Super Contributor
timestamp: October 23, 2013, 06:10:23 pm
content: Quote from: Neilm on October 23, 2013, 05:52:48 pmSome railway systems use 16.67 Hz, but in the UK the electrical supply comes directly from the grid. The overhead electrical supply on nearly all of the UK rail network is 25 kV AC, 50 Hz.

author: free_electron
author_rank: Super Contributor
timestamp: October 23, 2013, 06:42:23 pm
content: the 50hz 60 hz :us started with 60 hz simply because the 'governors' (the speed regulation mechanism of a steam generator ) were compared with a known time movement : a clock... 60 minutes in an hour , 60 seconds a minute : add another 60 tooth gear and you have 60 subdivisions of a second... ...so these were easy to construct in quantity. the gears were available. a standard clock could be used to regulate the speed of the generator.

author: rexxar
author_rank: Frequent Contributor
timestamp: October 23, 2013, 07:33:26 pm
content: Quote from: free_electron on October 23, 2013, 06:42:23 pmThat's fascinating, and really clever engineering!I'm imagining a big grandfather clock with a belt running out to a huge steam engine lol

author: G7PSK
author_rank: Super Contributor
timestamp: October 23, 2013, 08:22:46 pm
content: Some railways in the UK used to run on 25 HZ I have a frequency meter from such.

author: G7PSK
author_rank: Super Contributor
timestamp: October 24, 2013, 08:22:09 am
content: Quote from: Neilm on October 23, 2013, 05:52:48 pmWhen my parents moved us from London to Cambridge in 1960 there was a delay in moving into the new house as it was being converted from DC to AC so my father decided that the whole house would be re-wired and the new style plugs and sockets fitted, which turned out to be a curse at first as every one else was still using round pins in Cambridge at that time, the conversion from DC to AC was not all done at once but in stages, in 1961-62 I was going to a private tutor as my mother did not like my hand writing the tutor who lived ten minutes walk from where we lived was on DC when I started there then one day when I went she was afraid to turn on the lights, the street had been switched to AC all her appliances had been converted where necessary but as the voltage was higher 250 volts instead of 200 she was scared of an electric shock if she touched the switch, I turned the lights on for her I was 9 or 10 at the time and found that the conversion was far more interesting than writing lessons.I used to walk past the old Cambridge power station on the way to school some times, had to take the long way to do so but I liked to look through the windows which had steel slats over them, you could hear the hum and see a greenish light inside as by that time they had stopped generating and the plant was producing DC for the parts of the town that were still on it from the grid via transformers and mercury arc rectifiers. So at least for Cambridge DC was still in use at the beginning of the 1960's.As for plugs a book could be written on those, my grand parent who all lived in London had at least 4 different types of sockets in their houses from 2 pin to 3 pin 2 amp to 15 amp. all round pins.

author: Steffen
author_rank: Regular Contributor
timestamp: October 24, 2013, 07:14:33 pm
content: Quote from: Tepe on October 23, 2013, 12:36:56 pmWhat the hell did i just see? 400 Volts with this connector? Ouch. Better take these ones:

author: G7PSK
author_rank: Super Contributor
timestamp: October 24, 2013, 08:09:39 pm
content: Yes. I only use cee form plugs and sockets in my workshop, bulky but in my opinion the best. That looks like a 16 amp plug with a 32 amp lead socket 4+E.

author: Tepe
author_rank: Frequent Contributor
timestamp: October 24, 2013, 08:46:12 pm
content: Quote from: Steffen on October 24, 2013, 07:14:33 pmThey mate with sockets with a deep cavity and can only be inserted one way:

author: Monkeh
author_rank: Super Contributor
timestamp: October 24, 2013, 08:47:22 pm
content: They look flimsy, aren't IP44, don't support phase swapping..The rest of us will stick with decent ones, thanks.

author: Tepe
author_rank: Frequent Contributor
timestamp: October 24, 2013, 08:58:31 pm
content: Quote from: Monkeh on October 24, 2013, 08:47:22 pmThey are bigger than you think. Nothing flimsy about them.

author: AlfBaz
author_rank: Super Contributor
timestamp: October 24, 2013, 10:18:12 pm
content: Quote from: free_electron on October 23, 2013, 06:42:23 pmSo in essence 60Hz is due to the 5000 year old Babylonian number system

author: Kryoclasm
author_rank: Regular Contributor
timestamp: October 25, 2013, 01:32:16 am
content: Quote from: AlfBaz on October 24, 2013, 10:18:12 pmNothing wrong with tradition.

author: G7PSK
author_rank: Super Contributor
timestamp: October 25, 2013, 09:31:25 am
content: Some interesting reading here.http://en.wikipedia.org/wiki/Utility_frequencyhttp://edisontechcenter.org/Niagara.htmhttp://en.wikipedia.org/wiki/Mains_electricity

author: Tepe
author_rank: Frequent Contributor
timestamp: October 25, 2013, 11:36:54 am
content: Quote from: Monkeh on October 24, 2013, 08:47:22 pmIf water ingress is a worry:

author: Monkeh
author_rank: Super Contributor
timestamp: October 25, 2013, 11:38:11 am
content: Quote from: Tepe on October 25, 2013, 11:36:54 amIEC 60309 is IP44 all by itself, without needing some massive hinged contraption, full of parts to corrode.

author: Tepe
author_rank: Frequent Contributor
timestamp: October 25, 2013, 11:46:11 am
content: Quote from: Monkeh on October 25, 2013, 11:38:11 amYeah, but then you don't get those manly, strong springs. The switch also requires a surprising amount of force to flip giving the person flipping it a nice feeling of accomplishment when (s)he is rewarded with a loud click.(U.S. readers should note that O is up and I is down)Edit:Anyway, these days the CEE counterparts are increasingly common here as well. But versions of the old-style sockets are still popular for use behind stoves, etc. - either with the socket facing down or by using an angled connector - simply because they take up rather less space than the CEE ones do.

author: peter.mitchell
author_rank: Super Contributor
timestamp: October 25, 2013, 12:17:40 pm
content: http://liveimages.quicksales.com.au/quicksales/general/classified/gc5413829115260404921.jpgShe's a beauty isn't she? IP56, a hole in the switch to put a lock through if you wish to lock the outlet, a nice manly spring on the door...

author: Tepe
author_rank: Frequent Contributor
timestamp: October 25, 2013, 12:24:11 pm
content: Quote from: peter.mitchell on October 25, 2013, 12:17:40 pmSure is. And just as clumsyBut if Monkeh is right, why the door?

author: david77
author_rank: Frequent Contributor
timestamp: October 25, 2013, 04:42:55 pm
content: That Danish connector looks evil, why not just use what the rest of Europe has settled on?This was the 3-phase connector used in Germany in the olden days. A massive full metal construction that was so badly thought out it could kill the user. The authorities recognized this and made it mandatory to replace them with CEE plugs and sockets in 1980. One of the very few times it was made mandatory to update electrical installations.Apparently the problem was they use only 4 conductors, so you'd have L1, L2, L3 and PEN. The cases being made of aluminium neeided to be grounded, so they were connected to PEN.As you can see the pin arrangement is symmetrical, the only polarization through the metal tabs on the plug. These tended to break of rather easily through use in rough envirnonments making it possible to reverse the plug, thus putting full line voltage on the case and the person inserting it.Only using 4 conductors also made the use of RCD's impossible. These things were death traps.

author: Steffen
author_rank: Regular Contributor
timestamp: October 25, 2013, 05:39:37 pm
content: Here is another example of a more compact version for 3L/N/PE connectors for German 380/400V:The Name for this is "Perilex". The orientation of the certerpin indicates use for 16 or 25A.The Perilex connector was popular in the 1960s and by law it had to be replaced till 1998 by CEE Connectors.

author: Tepe
author_rank: Frequent Contributor
timestamp: October 26, 2013, 07:33:39 am
content: Quote from: Steffen on October 25, 2013, 05:39:37 pmIt's also used in Sweden.

author: Tepe
author_rank: Frequent Contributor
timestamp: October 26, 2013, 07:37:55 am
content: Quote from: david77 on October 25, 2013, 04:42:55 pmIt's quite safe, nothing evil about it. As for your question, the answer is that it is happening.Quote from: david77 on October 25, 2013, 04:42:55 pmPre-war and/or East German type?

author: vk6zgo
author_rank: Super Contributor
timestamp: October 26, 2013, 09:51:59 am
content: Western Australia had 240v 40Hz at one time,but changed to 50Hz in the mid 1950s,or thereabout.The story (maybe an urban myth),is that the transformers were more efficient at 50Hz,giving around 250v,so the State standardised on 250V,50Hz.There was a thriving cottage industry in the 40Hz days,turning up record player idler wheels for the local frequency.When the changeover came about,the same people made 50Hz idlers--cheaper than the OEM ones,so did well then,too!

author: david77
author_rank: Frequent Contributor
timestamp: November 10, 2013, 09:09:41 pm
content: Quote from: Tepe on October 26, 2013, 07:37:55 amI'm not sure when they were introduced, could well have been pre 1945. They remained in use in West Germany and Austria until the 1980's and in East Germany till the Berlin wall fell over. In theory there should none be left in active service.I've only seen one example of these connectors in use in my lifetime. For a huge circular saw on a very remote farm in the Austrian alps.The one in the picture is indeed a East German model, recognisable by the TGL lettering on it. TGL was the East German equivalent to the West German DIN.

author: MartinX
author_rank: Regular Contributor
timestamp: November 10, 2013, 10:59:22 pm
content: In Sweden the deadly German connector was common until outlawed in 1989, I am surprised the Perilex connector is not permitted in Germany in Sweden it is still common and they are still installed in new houses, if you buy a new electric stove it has a Perilex connector as standard, almost every kitchen in Sweden has one of those outlets.Before WWII Sweden had a hotchpotch of different voltages and frequencies and DC was common also, in the city I live in the last area that used 127V DC was not converted to 220V 50Hz until 1960. It is the same story as in most parts of the world, in the beginning power production and distribution was local and that lead to all the local variants but when the big nation and continent covering distribution networks were built that set the standard.

author: moemoe
author_rank: Regular Contributor
timestamp: November 10, 2013, 11:37:36 pm
content: Quote from: MartinX on November 10, 2013, 10:59:22 pmIt's not common here, but the Perilex connector is not forbidden, too.The old flat DIN 49450 connector is forbidden since 1975, at least in Western Germany.

author: moemoe
author_rank: Regular Contributor
timestamp: November 10, 2013, 11:40:06 pm
content: Sorry, can't edit my post with tapatalk, but just foundhttp://en.m.wikipedia.org/wiki/PerilexSo the old 4 pin connector was not used in Eastern Germany at all.

author: david77
author_rank: Frequent Contributor
timestamp: November 10, 2013, 11:57:47 pm
content: That's not true. The old style DIN (colloquially known as "Kraftstromstecker") connector was used in the GDR until its demise in 1990.Even the Wiki article you linked to confirms that.QuoteI would challenge the Wiki article where it says that Perilex was introduced to replace the DIN49450/1 connectors. The old style connector existed in versions for far more than 25 amps and Perilex was also never intended for heavy use on building sites and in workshops. Perilex was strictly for light usage such as machinery in bakeries or at the butchers shop and for domestic use like stoves or boilers and such. I've never come across a ruggedized version of it.In the end it does not matter one bit, of course.

author: JackOfVA
author_rank: Unknown
timestamp: November 11, 2013, 12:35:16 am
content: "Men and Volts" is a book written in the 1920's covering the early years of Edison and then General Electric.According to Men and Volts, the origin of 110V in the US dates back to the original Edison DC distribution system. Because it was a nice round number and because early incandescent lamps worked well with it, the target lamp voltage was 100 V, DC. To allow for drop in the distribution network, an allowance of 10% was made so that the nominal power plant output was 110V. Depending on the distance to the generating plant, the customer might receive anything between 100 and 110 V.The DC distribution network was a 3-wire system with + / gnd / - so that the voltage between the + and - polarities was 220V, and lamps, etc. were operated between either +/gnd or -/gnd.When AC displaced DC, it was necessary to maintain the same voltage; hence 110V RMS was adopted. Since AC power was distributed at a higher voltage and stepped down the user's voltage could be set more or less independently of distance, most customers received 110V, not the 100 nominal from the early DC plants.Over time, to improve distribution efficiencies, the nominal home voltage in the US crept upward. First, 110, then 115, then 117.5 and now 120V. A cynic might also note that resistive loads such as incandescent lamps and heating elements consumed more power as the supply voltage crept upward, and hence the power company could sell more power and increase revenue by sliding the line voltage upward.Some older office buildings in Detroit MI had local DC power distribution into the 1960's -- for heating plants and elevators mostly. These were supplied by in-building motor generator sets after Detroit Edison terminated DC generation.I believe parts of the electrified AMTRAC northeast (USA) railroad system had 25 Hz traction motors until the last decade or so, and in fact there may well be some 25 Hz traction motors still in use.

author: moepower
author_rank: Contributor
timestamp: November 11, 2013, 06:10:49 am
content: Just a note, technically Australia is now on the 230V/400V standard, not 240V/415V. The standard was introduced in 2000, and industry is suppose to be migrating to the new voltages. However, because 240V is still within the tolerances of the new standard, 230 +10%, -6%, lot of utilities are not bothering to change.

author: moemoe
author_rank: Regular Contributor
timestamp: November 11, 2013, 09:27:24 am
content: Quote from: david77 on November 10, 2013, 11:57:47 pmI'm sure I read "did not exist in East Germany" yesterday evening. It was probably just too late for me.And just to clarify things, Perilex is not allowed in every sector, but just for households, hospitals and small companies, mainly because it's still smaller and easier to clean than CEE.