Why was 120V chosen as the standard voltage of homes in the US and not some other voltage?

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The reason that 120v service was chosen, was economic. Originally electricity was delivered to homes, and most businesses, for a single purpose and that was lighting. Can openers, TVs, washers, dryers, electrical factory machinery, etc. came later. At the time the most cost effective form of light bulb was a carbon filament bulb that operated best (optimally) at 100v to 110v. This, adjusted for transmission voltage drop, set most supply lines at 120v.

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By the time cost effective, and higher voltage, metal filament bulbs were brought to the market, most of the cities in the USA were already running 120v supply lines. Europe was just starting such systems and opted for higher voltage supply lines.

Higher voltages are used for long distance transmission and power distribution because more power can be transferred over the same size wire at a higher voltage (lower current). Power generation plants often use voltages in the hundreds of thousands, 115,000 to 165,000 of volts to move power over long distances. For lines of up to 20 miles long around a city, 2400 volts works well to reduce the voltage loss in the wires.

In North America, the electrical power lines going to residential streets and roads are operated at a primary voltage of 7200 volts. This voltage (12500/1.73 = 7225) is one leg from a three phase 12500 volt primary line. On the secondary of the transformers it is center tapped to provide 120 volts from each 240-volt leg to the center point. The center point is electrically neutral. The actual measured voltage in your house receptacle circuits will normally be 110 to 120 volts. All appliances are rated for the minimum operating voltage (110-115). This is the cause of confusion about the actual level of the supply voltages.

Different nominal voltage level and frequency standards are used in different countries. Europeans - and many other countries around the world - use 50 Hz (cycles per second) as the alternating frequency, not 60Hz as is used in North America and, again, many other countries around the world. The reason to use a higher voltage is that it is more economical because the current is less, so the wires can be smaller. On the other hand, the reason to use lower voltage in homes is safety: the lower the voltage, the safer it is.

If you have 10 amps drawing on one leg of your 240/120 service, and 10 amps on the other leg, the I2R losses are one fourth what they would be if you had 20 amps on just the one leg.

The Europeans use 415/240 (415/1.73 = 240), so their I2R losses are 1/16th of our 120 volt losses, with 20 amps drawing on just one leg.

480 V center tapped (split phase) is used in the UK only rarely, typically in rural areas to supply an isolated small group of houses that can be fed off a single phase overhead spur. Most houses and small businesses are supplied with 240 V single phase taken from a 415 V three phase local system, fed from a transformer of up to 700 KVA connected to the 11 kV distribution system. The voltage is mostly 240 V but is nominally described as 230 V with a suitably wide tolerance, to comply with European standards.

Originally, the service voltage was about 90 volts direct current, which was Edison's plan. Tesla proposed that the electrical grid be alternating current (AC) and competed with Edison for the first generating plant to be built in the State of New York at Niagara Falls. Edison proposed a DC system and Tesla an AC system. History tells us that Tesla won the competition, and because of that the industrial revolution was quickly accelerated. Had Edison won we would probably still be in the dark ages because of the inefficiency of transmitting DC current over long distances. While Edison was promoting the electrical light bulb around the country, almost every town required its own generating station because DC would lose so much in the transmission that it became unusable after only a couple of miles.

Tesla also had invented the poly phase alternating current generators that provided for the ability to generate the voltages necessary for long distance transmission. Tesla kept the voltage about the same as what Edison started but raised it to the 110 volts alternating current (VAC) because of the higher related voltages of 220 VAC and 440 VAC, which were integral to the more efficient poly phase generators.

The standard voltage available in most parts of the country (US) is now nominally 120 VAC volts +/- 10%, and can vary from 108 VAC to 132 VAC. It's usually around 117-118 VAC.

Transmission distances, the actual power needed in a neighborhood, cost, efficiency and safety issues dictate service parameters. Common distribution voltages run up to 16,000 volts. 12,000 is very common but there is still a lot of activity adding on to legacy distribution grids at lower voltages. A 2400 volt primary is very low for a distribution transformer.

In actuality power transmission is over many miles and the transmission voltage is more then 110kV. In fact interstate transmission is in the range of close to 500kV. At a substation it is reduced to 16kV for local area distribution. Transmission for the whole of the grid in North America is all tied together . Why? For economy and reliability. For example in the Summer some states do not use air conditioning but in Las Vegas, Nevada they do, so they actually buy the power from Canada in the summer because it is cost effective and reduces the need for more generation plants. Even then reserve spin power must be sustained for peak demands. Because power plants cannot produce near instant acceleration to meet new demands. In many cities and other peak demand areas, specialist peakers work to ensure that the the integrity of the grid is always maintained. 240 v is standard for the USA but only one phase is used and the transformer center tap is grounded, making it safer. Also, the main frequency of 60 Hz produced by power generation is not as stable as some people think. It varies throughout the day as loading changes but the controllers must legally ensure that it averages 60Hz over a complete day so that electric clocks using synchronous motors remain accurate.
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Is it possible to use the 240V oven outlet and convert the voltage to standard 120V with some kind of external adapter?

Yes, but I do not know of an adapter per se. Expose your 220V power lines. There should be two hot wires (black and red). They can technically be split apart and wired to two separate 110V outlets, but the neutral wire would have to be shared (not split, shared), same with the ground wire. Answer ( Full Answer )

Will an HDTV made for 120V 60hz work in 240V 50hz if you use a voltage converter?

Answer Yes - but picture quality will be affected. Try also buyinga frequency convertor - maybe there is one on the market that doesboth. Check the TV Most modern TVs use a switching power supply asit is lighter and cheaper than a transformer. Switchers don't careabout frequency (at all) as they imm ( Full Answer )

What is voltage?

A type of "pressure" that drives electrical charges through acircuit. Voltage is how the electric potential energy differencesare measured.

What DVM voltage range do you use to measure house current voltage 110Vor 120V Why?

You must set the range so that the maximum value is greater than the conventional voltage levels in your house. Like, in the United States, the common voltage level is 120 volts RMS, although many homes are equipped with 240-volt service, to accommodate certain appliances, like clothes dryers. (The ( Full Answer )

What voltage range should be used when using a digital volt meter or digital multimeter to measure standard house voltages in the United States?

Digital Volt Meters . If your meter lacks an auto-ranging function (many inexpensive units lack such a feature), you must set the range so that the maximum value is greater than the conventional voltage levels in your house. In the United States, the common voltage level is 120 volts RMS, althoug ( Full Answer )

What is the max voltage for a us home?

US homes use a 240 volt single phase 'Edison' system. It is a 3-wire (4 with the ground) system. Phase to phase measures 240v, while each phase to neutral measures 120v.

Will a DVD made for 120V 60Hz work in 240V 50Hz if you use a voltage converter?

Maybe.... most modern equipment will operate on 90V - 260V so it's worth checking before buying a voltage converter for it.. If the DVD player is 120V, that suggests that it is North American and will play NTSC standard discs. Using it on a 240V region means it is likely that it will be in a PAL z ( Full Answer )

What are the standard voltages for transmission?

The standard voltage for transmission is about 115 to 1,200 kV(long-distance transmission). The extreme high voltages aremeasured more than 2,000 kV and it is exists between conductor andground. Answer for UK The standard transmission voltages in the UK are 400 kV and 275 kV.Primary distribut ( Full Answer )

What Voltage type are in outlets at home?

Most outlets in a house in the United States are 120 vac (volts alternating current). There are some that are 240 vac for dryers, ranges and other misc. appliances.

How is the voltage for homes shipped to a home?

Voltage isn't "shipped", really. Generator terminal voltage is typically in the range of 10-30kV; they are connected to the bulk electric system by step up transformers that convert this 10-30kV into voltage in excess of 100kV for power transmission. Near your home, this voltage is again stepped dow ( Full Answer )

How does us standard 208-120 AC voltage differ from standard European 415-240 AC voltage?

North American and European countries use completely-differentresidential supply systems. To start with, North American supplies are not 208/120 V, assuggested in your question. This implies that the secondary windingof a transformer is wye connected whereas, in fact, they aredelta-connected. Hom ( Full Answer )

What is the standard voltage in Japan?

Standard single phase AC voltage in Japan is 100 volts. The frequency is not the same throughout the country however. Eastern Japan is predominantly 50 Hz while the west prefers 60 Hz. . Three phase voltage is 200 volts. . http://users.telenet.be/worldstandards/electricity.htm Answer . Japan use ( Full Answer )

Why do you have AC voltage in homes?

Alternating Current is safer than Direct Current Answer Because (1) you electricity utility supplies a.c., not d.c., and (2) the ease with which a.c. voltages can be changed and rectified for equipment (e.g. audio equipment) that requires d.c.

What voltage is used in homes in Canada?

The standard home voltage in Canada is 120/240 supplied at 60 Hertz. Further information Homes in Canada use 240/120 volts at 60 cycles per second (60Hz) single phase. It is a split-phase system that delivers 240 volts to large domestic appliances (e.g. washing machines, dryers, air-conditioner ( Full Answer )

What is the electrical voltage standard in the US?

120/240 volts at 60 cycles per second ac. It is supplied as a single phase service, split 120V-0-120V. One hot leg is 120 volts, a second hot leg 120 volts but running at 180 degrees out of phase from the first leg, and a neutral. Every 120 volt outlet in your home carries one leg of 120 vo ( Full Answer )

What causes low voltage in homes?

That's often caused by improperly sized wire that's too small for the distance. It can also be a problem with connections that aren't tight enough or are corroded. Contact a qualified electrician to find your problem.

Can you use an appliance designed for 120v in a country where the voltage used is 240v without damaging or breaking the appliance or is it necessary to use a voltage converter?

Some 120 Volt appliances, such as electric shavers, etc., have been designed to run safely on different supply voltages and frequencies. If that is so, it would be stated on their rating plates.. In many cases, where the power needed is low, such as (say) less than 30 Watts, a cheap and simple "Int ( Full Answer )

What voltage used in homes?

Depends on country USA has lower voltage than UK in the US it is 120 V UK uses 240 volts Answer The United States and Canada uses a split-phase system, that supplies a residence with a nominal 240 / 120 V . 240 V is used for high-power appliances (e.g. stoves, driers), whereas lighting and ( Full Answer )

How much is the secondry voltage vs with a primary voltage is vp equals 120v?

As far as a transformer is concerned, the secondary voltage Vs value cannot be determined by the primary voltage Vp alone. For the simplest of calculations the transformer primary-secondary turn ratio must be known. For an ideal transformer ( and practicaly ideal transformers don't exist as there wi ( Full Answer )

Why is that alternating voltage is used in appliances in homes not direct voltage and mixed voltage?

Alternating current is used in the bulk electric system for power transportation because it is easier to step up/down voltage, therefore easier to minimize loss due to transporting over a long distance. Voltage is stepped up / down using transformers. In the bulk electric system, there are DC power ( Full Answer )

What is the total voltage a normal home uses?

Total voltage that you use in your home is constant. For Europe ~230V, for US ~120V. But the total power that you use differs and depends on total power consumption of the devices you use [Watt/h].

What voltage is commonly found in homes?

In North America 120/240 is the main voltages used. It is known as a three wire system. L1 to L2 supplies 240 volts. L1 to N supplies 120 volts and L2 to N supplies 120 volts.

Why are high voltages not used in the home?

because you will get shocked High voltages are not used in residential settings primarily because of electro-magnetic interference. Although it would be much more efficient you would never be able to watch tv,listen to a radio...etc. Answer High voltages are only necessary for the transmis ( Full Answer )

How much voltage you are getting at home?

Your residential voltage is specified in terms of a 'nominal' ('named') value, but is allowed to vary within limits specified by relevant statutory regulations. In the UK, for example, the nominal voltage is 230 V, but it is allowed to vary between +10% and -6%. In other words, it is allowed to vary ( Full Answer )

How much voltage use in home in India?

It is 230V single phase and 440V in 3 phase system at 50 Hz. Answer If the single-phase voltage is 230 V, then the three-phase voltage must be 400 V, not 440 V. The line voltage is 1.732 times the phase voltage.

Are home laundry driers in the US using 220 voltage?

The majority of dryers in the US are rated at 240 volts. There are some smaller sizes that are used in small apartments that use 120 volts. These just plug into a regular receptacle outlet. They will only handle a small load and take quite a bit of time to completely dry the clothes.

Why some countries use low voltage but others use high voltage?

You must understand that with higher Voltage you will get lower amounts of current therefore some countries use lower household current applications therefore without diminishing circuit efficiency it is more ideal to up the Voltage Answer The main advantage of using a higher value ( Full Answer )

What is the voltage received at home?

Voltage will vary from one country to another, for example in the UK it's around 230 volts in Canada is around 120 volts. Ask the question again stating which country/region/state you need to know about.

What is the difference from between the voltage from the photocells and the voltage used in the home?

Voltage coming from a single photovoltaic cell is around 0.5 volts or the equivalent of a dead AA battery from your remote. It also moves in a straight line. This is called DC or Direct Current. The power Coming out of the outlet in your house is 120 volt that is equal to 240 photovoltaic cells or s ( Full Answer )

Why use 240V electricity voltage in homes?

The answer is not as simple as just this, but one factor is the fact that amperage is reduced as voltage goes up, and less amperage means smaller wire can be used, and smaller wire means less cost to build. But electrical engineers would tell you about advantages too. Answer There are two way ( Full Answer )

How do you fix fluctuating voltage in your home?

You would need something called a voltage regulator. A voltageregulator is essentially a bank of capacitors. The mains is fedinto the circuit, and the capacitors 'absorb' the spikes andtroughs of the raw voltage. The power exits the device at aconstant, stable voltage.