Looking at the list of domestic voltages and frequencies around the world on Wikipedia, how did countries like South Korea, The Philippines, Peru, Guyana and parts of Brazil end up with the European 220-240 voltage but with 60Hz American frequency? Also, is there any advantage using this somewhat odd combination vs. the usual 120v/60Hz or 230V/50Hz?
I heard once that 220 volts at 60c/s is the best most efficient supply for motor loads
I'm not sure where you heard that, AnnMarie. 3 phase 400V motors certainly have advantages over their single phase counterparts, as in they are more efficient, quieter, are pretty much self-starting and draw less current for a given size of motor. Of course, you do need to have a 3 phase supply to take advantage of this.
Back in the 70's when I was there South Korea used 100/110 volts 60Hz with US type plugs and sockets. They have now upgraded to 220v with Schuko type plugs and sockets. Presumably changing frequency as well would be too much of an upheaval. I imagine the same or similar has happened elsewhere.
I imagine the Philippians are simply reflecting the influence of the Americans over the last century. Why they dropped the 120 volts and only use 240 may just be because it is a more efficient use of the copper.
As for the voltages. FPL says this in their service standards
The state of Florida requires that utilities normally operate within a range of plus- or minus six volts (114 - 126) from standard voltage (120).
So you see all of those voltages are within the nominal 120.
True, the funny thing is that American-style type A/B plugs and sockets are still being used here in the Philippines at 230V making things fun for equipment imported from North America if you're not careful
For those interested, here is a PDF document with the specifics of the utility (Meralco) serving the capital Manila and surrounding area.
In Austria and Germany there's been a push for several decades to get rid of any single-phase 2-wire services in favour of 3-phase 4-wire. In both countries (that share a common VDE legacy 1938-1961) direct metering is only available up to 63 A and single-phase services were usually only provided up to 35 A/230 V (as of 2015, Vienna Grids is the only operator that I'm aware of still providing the option of single-phase connections, requiring 6 mm2 meter tails and usually fused at 25 A). The current standard setup for homes and apartments in Austria is 35 A 3-phase. In Germany, some grid operators require 63 A as the only size for domestic connections, others prefer smaller services.
Larger single-phase services are frowned upon as it seems that our grid operators don't believe in load balancing over several services and require each service to be balanced (i.e. the circuits being evenly distributed across all three phases).
Back to the topic of motors: the higher the frequency the smaller motors (and transformers) can be, that's why 400 Hz is used commonly in aircrafts. Apparently the European 50 Hz just became a de-facto standard by evolution, whereas the US 60 Hz were chosen for practicability and low-flicker arc lamps.
All very interesting I heard that 220V 60c/s was best on some TV documentary a few years ago I was a bit surprised but just assumed it must be true if the TV said it! Ah well maybe I was a bit naive. As for Austrian and German supply's how do you run a whole house on 25 amps supply? In my house our peak load is about 45 amps admitidley only for maybe 10 mins a day and not everyday in fact only 2 or 3 days a week normally
As for Austrian and German supply's how do you run a whole house on 25 amps supply? In my house our peak load is about 45 amps admitidley only for maybe 10 mins a day and not everyday in fact only 2 or 3 days a week normally
A house will usually have 3-phase so assuming mainly 1-ph loads you have 75 A available at 25 A per phase. In a flat with gas-fired combi boiler and gas cooker you'd be hard-pressed to exceed 25 A single-phase, I've never managed to do that. I suppose you could try running washing machine, dishwasher and kettle at the same time but that's a rather rare occasion and both washing machine and dishwasher cycle the heating elements on and off.
Now in Italy with their 15 A 1-ph supplies it gets scary... electric oven and immersion heater are enough to plunge the house into darkness, so don't shower while something's in the oven!
I do have to say I'm a bit wary adding an electric oven to the 25 A 1-ph supply we've got here (there's been talk about that lately because the new gas oven is much worse than the old one even though the door of the old one had to be wedged shut with a wooden stick held in place by a half-open drawer) but if we avoid running oven and dishwasher at the same time we could even do that I guess.