why 115v and not 230v

[goontron]

why do they use 115v in the u.s. instead of of 230v it pisses me off when my crap don't work!
and in Australia i took us 115v crap and connected it to my mains to watch it smoke, but now to get Aussie power i have to go phase to phase and filter and regulate and use a VFD to get 50hz! so WTF!

[Rulycat]

Re: why 115v and not 230v

I believe 230V is more efficient for SMPS but 115V is safer.

[mariushm]

Re: why 115v and not 230v

It's historical reasons... Edison started to distribute electricity at DC 110v but Tesla being the genius that he was calculated that three phase 240v AC at 60 Hz would be the best for power distribution.

But Edison didn't want to say Tesla is right, he thought DC was better... he even did public campaigns where he was killing animals with AC current to prove AC power was not safe and crap like that.

In the end, he had to accept and go with AC voltage and 60 Hz but he stuck with 110v claiming it is safer, but the reality was probably that he didn't want Tesla to be right. Tesla eventually also gave up and let it be 110v.

See this, it's really entertaining: http://theoatmeal.com/comics/tesla

So yeah, 240v is better as you can use thinner wires. There is an increase in efficiency due to the high voltage, but modern power supply use active pfc boosting the voltage to around 400v so it's not that more efficient.

quoting wikipedia:

Choice of voltage

The choice of utilization voltage is due more to historical reasons than optimization of the distribution system—once a voltage is in use and equipment using this voltage is widespread, changing voltage is a drastic and expensive measure. A 230 V distribution system will use less conductor material to deliver a given amount of power because the current, and consequently the resistive loss, is lower than for a 120 V system. While large heating appliances can use smaller conductors at 230 V for the same output rating, few household appliances use anything like the full capacity of the outlet to which they are connected. Minimum wire size for hand-held or portable equipment is usually restricted by the mechanical strength of the conductors. Electrical appliances are used extensively in homes in both 230 V and 120 V system countries. National electrical codes prescribe wiring methods intended to minimize the risk of electric shock and fire.

Many areas using (nominally) 120 V make use of three-wire, single-phase 240 V systems to supply large appliances. Three-phase systems can be connected to give various combinations of voltage, suitable for use by different classes of equipment. Where both single-phase and three-phase loads are served by an electrical system, the system may be labelled with both voltages such as 120/208 or 230/400 V, to show the line-to-neutral voltage and the line-to-line voltage.

If you think 110v is a pain, go to Japan where some regions have 110v, some 127v... some have 50Hz and some have 60 Hz ... again historical, as UK was in charge of reconstruction of the country after the war so they brought generators with them from the 50Hz based Europe.

[severach]

Re: why 115v and not 230v

http://en.wikipedia.org/wiki/War_of_Currents

At the time it was felt that 100 volts was not likely to present a severe hazard of fatal electric shock.

100v was the voltage chosen for DC which came out first. For AC to be accepted it had to be compatible with at least some DC equipment already in place. 110v AC was completely compatible with lights and some equipment. Many corded power drills can run from DC or AC. AC and transformers allowed 220v to be broken up into two legs of 110v for existing equipment and devices handled by consumers. 220v could be used to increase the efficiency of equipment with high power requirements and little shock hazard. Over time 110v was increased to 120v to get more power through the same transmission lines. The voltage increase was small enough that most existing equipment was compatible.

I can place my fingers across 120v just for fun. I won't try that with 240v. The problem isn't that the current doubles. The problem is that the higher voltage makes more paths available. Paths that would not conduct at all at 120v may conduct at 240v. You'll probably live if you get tangled up with 120v. You probably won't if you walk on the 480v supply rails of a gantry crane or fall on the power rails of a subway train. 120v, 480v, what's the difference, right? What can 500,000 volts do for you?

For example, at 480v a spark plug is an open circuit. At 50,000 volts a spark plug is a conductor. If something doesn't conduct BHG says "what if we tried more voltage?"

I ask why we don't all use 3 phase? 3 phase offers a big efficiency increase for electric motors and 480v radios work great in the bath tub.

[ben7]

Re: why 115v and not 230v

I don't have a clue.

I don't have as much frustration over different voltages as I do with weight and mass, inches and centimeters, gallons and liters (whoops, I meant 'litres').

[turbozutek]

Re: why 115v and not 230v

Here's another simple question: why don't you wire your (North American / Canadian) houses using ring main?

I love it when I plug in a vacuum cleaner or switch on the microwave and every lamp on that circuit dims! I'm sure that doesn't cause many house fires.

Chris...

[tom66]

Re: why 115v and not 230v

Ring main saves copper (great after WWII), but allows you to easily overload the circuit if one conductor fails unnoticed.

Another question for Americans, why aren't the majority of appliances earthed? It seems like a lot of equipment there uses two pins only...

[TELVM]

Re: why 115v and not 230v

... But Edison didn't want to say Tesla is right, he thought DC was better... he even did public campaigns where he was killing animals with AC current to prove AC power was not safe and crap like that ...

And he didn't just electrocute guinea pigs

[stevo1210]

Re: why 115v and not 230v

How many countries still use 110V nowadays? I know USA and Japan do... but I do know the EU and most of Asia is 220-240V 50Hz, and uses the metric system (Except the UK).

[mariushm]

Re: why 115v and not 230v

http://en.wikipedia.org/wiki/Mains_e...ity_by_country

Pretty much Americas, Japan, lots of islands, Lybia, Saudi Arabia and some parts of Brazil.

[PeteS in CA]

Re: why 115v and not 230v

The short answers are: history; vision; installed base inertia; nationalism.

History: these decisions were made over a century ago by people in various countries who were not working together with each other.

Vision: the application at hand was lighting, probably focused on large- and medium-sized cities; national grids and mass-produced electrical appliances were probably not envisioned, and mass-produced electronics were probably not even foreseeable; nor was producing and selling such in a global marketplace.

Installed base inertia: Do I need to explain the inertia of 100s or 1000s of millions of electrical appliances, electronic devices and basic things like power cords and light bulbs?

Nationalism: Do I need to explain this? Until recently, pretty much every country in EuroLand had incompatible power plug systems. Until recently, pretty much every country in EuroLand had their own, independent, sometimes conflicting, safety agency; to sell in each country, a company had to get their products approved in each country. A nice barrier to competition for domestic companies, but a prop supporting higher consumer prices.

[turbozutek]

Re: why 115v and not 230v

Ring main saves copper (great after WWII), but allows you to easily overload the circuit if one conductor fails unnoticed.

That's only true in UK installations where one single 32amp breaker serves the whole ring, left and right. There would be nothing stopping you having two 16 amp breakers supplying the ring from either side; if one conductor fails (which happens once every 40 years?) then the left or right side 16 amp will trip above the cable rating protecting the circuit from the situation you're outlining.

So much the better if the breaker is dual-pole.

The cost of the extra breaker would be nullified by the reduced cabling cost and you'd have a safer circuit overall, more immune to the effects of one high drain device pulling the whole circuit down or heating up the cable (which happens to me here with parallel wiring for sockets a lot, just plug an air-conditioner in at the end of that circuit and the fun starts).

Also, stevo1210, the UK uses Metric for everything except vehicle speed, distance and pints of lager. You'll purchase food in grammes, cable by the metre, paint by the litre, shipping is weighed in kilos, etc etc

Mixing the two is stupid, yes, but hopefully everyone in the UK who still uses imperial only dies off soon. It's not really taught in schools any more, other than as a historical footnote.

The biggest adaptation I had when I moved to Canada was purchasing equipment and supplies in a system I hadn't used in 20 years. Imperial: let it go already, it's dead.

Chris...

[goontron]

Re: why 115v and not 230v

Mixing the two is stupid, yes, but hopefully everyone in the UK who still uses imperial only dies off soon. It's not really taught in schools any more, other than as a historical footnote.

The biggest adaptation I had when I moved to Canada was purchasing equipment and supplies in a system I hadn't used in 20 years. Imperial: let it go already, it's dead.

Chris...

um ok?

[turbozutek]

Re: why 115v and not 230v

um ok?

So you'll convert to come in-line with the rest of the world!? Thanks goontron, that'll make my job much simpler!

To clarify, I'm working for a large producer of machinery right now (we make and repair stuff for the US, Europe and Canada) and the costs involved in having duplicate tooling, conversion and documentation between two systems of measurement is considerable and (IMHO) totally needless.

Some (very recognisable brand names, no less) parts even have a mixture of Imperial and Metric connectors and fittings on the same sub-assembly. It's a headache I'm unused to having, since I learnt and used the Metric system almost exclusively since age 5.

Chris...

[RJARRRPCGP]

Re: why 115v and not 230v

110V vs. 127 V = That would be a normal variation over in the US. Probably varies with poco.

With CVPS/GMP in Vermont, lower than 122 V often means something is taxing the circuit and 117 V means it's close to an overload. Usually because someone is running a hair dryer. (Might trip when turning on the PC o_O)

124 & 125 V is typical for GMP of central Vermont.

It actually looks like a poco in Oklahoma is less than 120 V. Apparently at 116 V and less!

GMP (Vermont) seems more towards the 127 V range. And Oklahoma seems to be more toward the 110 V range.

[ben7]

Re: why 115v and not 230v

110V vs. 127 V = That would be a normal variation over in the US. Probably varies with poco.

With CVPS/GMP in Vermont, lower than 122 V often means something is taxing the circuit and 117 V means it's close to an overload. Usually because someone is running a hair dryer. (Might trip when turning on the PC o_O)

124 & 125 V is typical for GMP of central Vermont.

It actually looks like a poco in Oklahoma is less than 120 V. Apparently at 116 V and less!

GMP (Vermont) seems more towards the 127 V range. And Oklahoma seems to be more toward the 110 V range.

We are close to the transformer (about 50 feet). The outlet at my workbench measures 120.6 volts The transformer is only about a year old, so that may be why it is so perfect (our house wiring was redone back in 2005. The old transformer died all of a sudden from an internal arc fault)

The 117v might not be from an overload. The ancient pole transformers might have a secondary voltage of 117v.

This is what I am talking about being ancient! An old westinghouse pole transformer (picture not mine!). This thing MUST have PCB's inside! :O

[gilly1984]

Re: why 115v and not 230v

That's only true in UK installations where one single 32amp breaker serves the whole ring, left and right. There would be nothing stopping you having two 16 amp breakers supplying the ring from either side; if one conductor fails (which happens once every 40 years?) then the left or right side 16 amp will trip above the cable rating protecting the circuit from the situation you're outlining.

So much the better if the breaker is dual-pole.

The cost of the extra breaker would be nullified by the reduced cabling cost and you'd have a safer circuit overall, more immune to the effects of one high drain device pulling the whole circuit down or heating up the cable (which happens to me here with parallel wiring for sockets a lot, just plug an air-conditioner in at the end of that circuit and the fun starts).

Also, stevo1210, the UK uses Metric for everything except vehicle speed, distance and pints of lager. You'll purchase food in grammes, cable by the metre, paint by the litre, shipping is weighed in kilos, etc etc

Mixing the two is stupid, yes, but hopefully everyone in the UK who still uses imperial only dies off soon. It's not really taught in schools any more, other than as a historical footnote.

The biggest adaptation I had when I moved to Canada was purchasing equipment and supplies in a system I hadn't used in 20 years. Imperial: let it go already, it's dead.

Chris...

Hi barman, 568.261485 millilitres of carlsberg export please.

[Per Hansson]

Re: why 115v and not 230v

Hi Barman, I'll have a Carlsberg Export please
-Large or small?
I'll take the 50cl (or half litre of you prefer)

Or 33cl if you're a wimp

[gilly1984]

Re: why 115v and not 230v

Pint will never die out in the uk Or miles.

[MrF]

Re: why 115v and not 230v

You would NEVER get circuits fed by 2 separate breakers past NICEIC, NAPIT or any of the other notification bodies, nor past the IET or CENELEC.

The way its headed is that UK will likely standardise back on radials (which would make working on houses so much easier, nightmare trying to work safely when the whole house's sockets are on one circuit and you need to use mains tools, usually means creating a temp circuit...thankfully not too many houses like that anymore but there are still a few) and ring mains will be eliminated, already kitchens are usually rewired on their own circuit due to load and sometimes multiple circuits to cover high inrush current items such as fridge freezers etc and high draw items like dryers etc.
I don't see the UK headed onto Europlugs anytime soon though, simply due to Xenophobia and also as the French stuff especially can have terrible quality control...