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World map of mains voltages and frequencies.
Fullsize image: https://diqn32j8nouaz.cloudfront.net...y_fullsize.jpg
https://diqn32j8nouaz.cloudfront.net..._frequency.jpg
Previously:
https://www.homemadetools.net/forum/...251#post204025
https://www.homemadetools.net/forum/...534#post201081
https://www.homemadetools.net/forum/...081#post195275
https://www.homemadetools.net/forum/...724#post193898
https://www.homemadetools.net/forum/...642#post189944
127 volt mains? You learn something new every day.
I'm in the big medium blue country and can tell you we're light blue.
Mains here are 220v for single phase and 380V for 3 phase. That's by my meter, labels on items, and electrician.
When I lived in Germany in the middle 1970s they called theirs 220single & 380 three phase@ 50hz. The last time I was in Germany every thing was marked 230 & 415-50hz the same as most of the rest of the EU countries it was the same way in Kuwait but not in Saudi Arabia.
here in Texas I remember while growing up our house had only a 30 amp 2 wire 110v supply until sometime around 1970 when the REA added the second half of the split phase to our house so we could run 220v machines in the barn this meant we had to install a 60 amp breaker panel instead of the screw in fuses, my uncle also rewired the house with grounded Romex and installed the 3 prong receptacles and drove a 20ft long copper rod in the ground by the meter. I seem to remember him saying something about us having 115v at the wall plugs after that which later became 120v A lot of people still refer the electric supply as 110 but the standard is 120 +/- 5% according to the NEC but it can range much wider than that. Back in the 1990s while installing machines in LA county California I saw readings as low as 100v and the HZ drop to below 57 then at different times the voltages could rise as high as 127 @ over 63 HZ 59to 61 is the acceptable norm for the NEC
I thought that was just what they called it until I put a meter on it. 223 volts.
Alec of Technology Connections has several videos that include discussion of the electrical grids He pointed out that the US and Canada actually have a 240 mains, but that some of the service is delivered to residential customers directly as 240v, and some are split into two 110v supply lines. Even a 240v service can be split at the electrical panel into two 110v circuits. It's still supplied to the pole as 240v.
It makes sense to do this since most electrical items that we use don't need more than 110v.
Neil
240 split is 120, 220 split is 110
3 phase voltage is the main voltage (240, 220) times the square root of 3 = 1.73
so 220 3 phase is 381 V while 240 3 phase is 416 Volts. Insert complicated vector math here to explain where the square root comes from.
3 phase was invented by a Mr Tesla (NOT Elon), it's a very efficient way to make a motor. One moving part, no switches, capacitors, etc. and they are easily reversible.
Another advantage of it is the higher voltage means you draw less amps for a given wattage ( A = W / V )
Where I am we are limited to 25 Amp main breakers since it's zoned "Dacha" (small house/farm). We simply have three 25 Amp main breakers. Now, how to best use that. The milling machine main motor would draw almost 7 Amps on 220 but on 3 phase the load is divided over all 3 breakers AND being 380 Volts the motor only draws about 1.3 Amps per phase!
This also allows us to have an electric sauna heater. The building code changed while we were in construction and they no longer allow gas heaters in saunas. That left wood and electric. We opted for electric because on 3 phase the load will "fit" on the main breakers as long as we don't have any other large stuff running. We can even run the sauna and the greenhouse heater at the same time if we're careful.
A footnote on 3 phase. If you're using high power dimmers such as in a theater or store or something, the math gets really strange for Wye configured systems and the neutral current can be TWICE the current on any other leg. More than one theater has learned what burned insulation smells like.