Different mains voltages and\or frequencies?

IOTL, there are two voltages used for mains electricity around the world; most countries use 240 VAC, while the US and a few others use 120 VAC. Likewise with frequencies: most countries use 50 Hz, while the US and a few others use 60 Hz.

But there's nothing, in principle, keeping countries from choosing 360 VAC or 480 VAC or even 600 VAC for their mains voltage instead, or using a completely metric electricity system (say, 1000 VAC 100 Hz). Or using a mains voltage lower than 120 VAC - maybe 60 or even 30 VAC?

So, what if there was a lot more variation in mains voltages and frequencies between countries than there is IOTL? What might we see?

(As an aside, it would be cool to see at least a handful of countries still using DC for their mains electricity - maybe small island nations where the lower transmission distance wouldn't be a problem?)
 
German railway networks use 16 2/3 Hz power, it wouldn't take a great deal to see that used for general distribution. 25 Hz and 40 Hz power have also been used by various suppliers in the past. Systems around 40 Hz in particular were quite popular, and a few survive to this day. 400 Hz is used for some specialised applications, but it's highly inefficient over long distances.

You could conceivably see some isolated areas run on 48V DC. Why 48V? Because that's the standard for phone lines; the ringing tone is 90V 20Hz. Either of these would make sense for a telephone company that branched out into electrical power supply.

More widespread three-phase power isn't out of the question; 400V is probably excessive for most domestic applications (though not all - cookers and showers could easily use it), but the odd US three-wire 240V system could easily be replaced by 208V three-phase.

Japan uses 100V rather than the standard 120V or 230V systems; this could become more widespread if many countries import large amounts of Japanese electrical equipment.

Pretty much any combination of frequency and voltage in the range of 100-250V, 25-133 Hz is plausible, though. Like most standards, mains electricity is basically the result of some arbitrary choices a century ago.
 

nbcman

Donor
IOTL, there are two voltages used for mains electricity around the world; most countries use 240 VAC, while the US and a few others use 120 VAC. Likewise with frequencies: most countries use 50 Hz, while the US and a few others use 60 Hz.

But there's nothing, in principle, keeping countries from choosing 360 VAC or 480 VAC or even 600 VAC for their mains voltage instead, or using a completely metric electricity system (say, 1000 VAC 100 Hz). Or using a mains voltage lower than 120 VAC - maybe 60 or even 30 VAC?

So, what if there was a lot more variation in mains voltages and frequencies between countries than there is IOTL? What might we see?

(As an aside, it would be cool to see at least a handful of countries still using DC for their mains electricity - maybe small island nations where the lower transmission distance wouldn't be a problem?)

The risk of arc flash increases as the voltage level increases. In the US, the Electrical Codes do not typically view voltages under 240 VAC as posing much of a risk for injury due to arc flash but once voltages are above that, additional precautions are required to service the electrical equipment and additional guarding is required. All of this costs money which precludes the use of voltages greater than 240 VAC in most non-industrial usages.

For the lower voltages, energy loss is related to the current squared times the resistance of the transmission media (wires). If the voltage is reduced, the current has to increase proportionally which increases loss. Reducing the voltage from 240 VAC to 30 VAC would increase losses by 64 times. This is one of the reasons why higher voltages are used for main transmission lines from power plants.
 
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IOTL, there are two voltages used for mains electricity around the world; most countries use 240 VAC, while the US and a few others use 120 VAC. Likewise with frequencies: most countries use 50 Hz, while the US and a few others use 60 Hz.

But there's nothing, in principle, keeping countries from choosing 360 VAC or 480 VAC or even 600 VAC for their mains voltage instead, or using a completely metric electricity system (say, 1000 VAC 100 Hz). Or using a mains voltage lower than 120 VAC - maybe 60 or even 30 VAC?


not 240V, the most used is 220/ 230V.
and three phase 400V is pretty common, especially for professional use.

https://en.wikipedia.org/wiki/Mains_electricity_by_country
 
The risk of arc flash increases as the voltage level increases. In the US, the Electrical Codes do not typically view voltages under 240 VAC as posing much of a risk for injury due to arc flash but once voltages are above that, additional precautions are required to service the electrical equipment and additional guarding is required. All of this costs money which precludes the use of voltages greater than 240 VAC in most non-industrial usages.

If a higher mains voltage (say 360 VAC) had been adopted early on, wouldn't the electric codes view that as the voltage that it's unsafe to go higher than, rather than OTL's choice of 240 VAC as a limit?

For the lower voltages, energy loss is related to the current squared times the resistance of the transmission media (wires). If the voltage is reduced, the current has to increase proportionally which increases loss. Reducing the voltage from 240 VAC to 30 VAC would increase losses by 64 times. This is one of the reasons why higher voltages are used for main transmission lines from power plants.

Presumably any countries using 60 VAC or 30 VAC would still use high voltages for long-distance transmission, only stepping down to low-voltage power close to the end users (concerns about 120 VAC being too "dangerous" might well be what triggers the adoption of a lower-voltage standard, in which case the benefits, and the low voltage, would be past the last substation anyways).
 
The risk of arc flash increases as the voltage level increases. In the US, the Electrical Codes do not typically view voltages under 240 VAC as posing much of a risk for injury due to arc flash but once voltages are above that, additional precautions are required to service the electrical equipment and additional guarding is required. All of this costs money which precludes the use of voltages greater than 240 VAC in most non-industrial usages.

For the lower voltages, energy loss is related to the current squared times the resistance of the transmission media (wires). If the voltage is reduced, the current has to increase proportionally which increases loss. Reducing the voltage from 240 VAC to 30 VAC would increase losses by 64 times. This is one of the reasons why higher voltages are used for main transmission lines from power plants.

I've seen 347 volts used for office lighting (not in a factory) outside of the USA. In one case the light switches were marked with 347V, presumably to warn maintenance staff of the voltage.
 
plus higher voltage allows an higher power output

typical house fuse being 16A
110V - 1760W
230V - 3680W
400V - 6400W (edit, mostly 400V 3-phase)
important especially for electric cooking, which usually exceeds even the 230V power.
 
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Input as an electrical engineer but not a power engineer:

Frequency-wise, both 50 and 60 Hz were basically arbitrary, but within certain constraints. First, there is a relationship between the frequency at which your turbines run and the frequency of electricity you make (they needn't be the same, but will be related by a half-integer factor). Though the simplest systems will have them the same, and turbines have various RPMs that they like to run at. Second, if you want to run incandescent lights off of your power, it needs to oscillate quickly enough that you can't see it (or, above roughly 30 Hz - the existence of the 25 Hz standard took advantage of the fact that the human eyes don't actually notice flickering that slow per se, though you'll notice certain effects (it would make everything look "movie-like"), plus the fact that the filaments in the bulbs had thermal inertia (i.e. it takes them time to cool down); it's also worth nothing that the 25Hz standard almost didn't happen because of the lighting issue, but manufacturing issues stopped this (the turbines involved in setting that standard spun very slow, and manufacturing turbines with many many poles was considered too expensive and unreliable). So 30ish Hz is the lower bound, and then there's also an upper bound provided by the limitations of induction motors (Tesla's model didn't work much above 100 Hz).

Someone pointed out that lower currents will have less losses than higher, but at the frequencies we're talking about that effect should be completely negligible.

Voltage-wise, we balance safety and efficiency...but the real reason for the range used today has to do with the materials used in the first generation of electrical equipment. In fact, I was taught that the reason that Europe is higher is because in the few years between the first American and first European power grids, materials (principally rubber) had advanced enough to safely support higher voltages. Plus, Americans were very wary because the War of the Currents had recently shown them all how "dangerous" AC was, even if they ended up using it.

Safety-wise, there's a major step in damage at about 200V, below which the electricity won't usually cause severe burns and above which it will (this is about the level required to cause major burning and breakdown in the outer layer of your skin); 110V is measurably safer than 220 (anecdotally, we were pretty blase about mains power in circuits lab, which I understand is not the case in most of Europe). Interestingly, safety-wise 60Hz is much more dangerous than 50Hz because it's much closer to the human pulse rate and so can more easily disturb the heart - but that wouldn't be realized OTL until long, long after the standard was adopted.

With regards to 3-phase, which someone mentioned: in the US, at least, power is always 3 phases on the high tension wires, and then will have phases isolated at the neighborhood or building level. Especially in apartment buildings between different apartments or floors, but also sometimes in individual houses, you can actually measure the voltage of different outlets against each other and see the 120 degree offset. The main reason that 3 phase isn't used more widely is the cost of handling it and the relatively small number of things that have a powerful enough motor to cause it to be more cost-effective to use a 3-phase motor.
 
Safety-wise, there's a major step in damage at about 200V, below which the electricity won't usually cause severe burns and above which it will (this is about the level required to cause major burning and breakdown in the outer layer of your skin); 110V is measurably safer than 220 (anecdotally, we were pretty blase about mains power in circuits lab, which I understand is not the case in most of Europe). Interestingly, safety-wise 60Hz is much more dangerous than 50Hz because it's much closer to the human pulse rate and so can more easily disturb the heart - but that wouldn't be realized OTL until long, long after the standard was adopted.
In my previous job we weren't allowed to use 240V portable power tools - we had to use 110V ones with an isolation transformer or battery powered ones for that very reason. Then again, it was a nuclear site so they were paranoid about safety.
 
not 240V, the most used is 220/ 230V.
Yep, although some places do use 240.

plus higher voltage allows an higher power output

typical house fuse being 16A
110V - 1760W
230V - 3680W
400V - 6400W
important especially for electric cooking, which usually exceeds even the 230V power.
Well I don't know about where you come from, but down here in NZ electric overs are rated at 230V 30-35A (6900-8050W). Common fuses are 5A, 10A or 15A.
 
plus higher voltage allows an higher power output

typical house fuse being 16A
110V - 1760W
230V - 3680W
400V - 6400W
In the UK, standard circuits are rated for 30A, with individual outlets rated for 13A - I'm given to understand that our ring circuit system is highly unsusual in that multiple outlets are connected to a single circuit. High-draw appliances like cookers are routinely fitted to a dedicated circuit with a 30A fuse and isolator switch; 45A circuits also exist but are rather uncommon - that equates to over 10 kW from a single appliance!
 
YWell I don't know about where you come from, but down here in NZ electric overs are rated at 230V 30-35A (6900-8050W). Common fuses are 5A, 10A or 15A.

netherlands
the total rating is about the same here @ 230V, maximum for entire house 40A, common block fuses are 10, 16A. with each block fitted with a automatic residual-current circuit breaker
the 400V is 3-phase (for cooking)
 
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Down here in NZ it's 40-60A total, I think depending on whether or not you have an electric or gas oven.
 
With regards to 3-phase, which someone mentioned: in the US, at least, power is always 3 phases on the high tension wires, and then will have phases isolated at the neighborhood or building level.

My (apparently very normal) house in Sweden has a 3-phase feed to a small cabinet on the outside wall containing 3 individual cartridge fuses plus a remote-reading meter. Then it runs up to a hefty panel of circuit breakers in the attic which feeds all the various circuits in the house, mostly single but some 3-phase like the cooker. Good points - super easy to add a 3-phase circuit for the wife's sewing machine, and for future use of heavy electric machinery outside like firewood processors. Downside - if one of those 3 external fuses goes, things connected to circuits getting half the expected power behave very oddly until you realise what has happened.
 
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