Before 1948, there was something particular about electricity in Southern California. Plug in a Warren/Telechron electric clock from outside the region and it would lose 10 minutes every hour. Play music on a record player from San Francisco and it would sound slow and drowsy. The reason ? Southern California's alternating current cycled at a frequency of 50 hz rather than 60 hz

A standard was not yet in place when the nations first commercial three-phase power generating and distribution system, Mill Creek No. 1 near Redlands, CA went online in 1893. As the generators and distribution system was being constructed, it was up to engineers at General Electric to determine the operating frequency. Westinghouse, GE's primary rival, was already designing equipment for 60 hz. However, GE decided on 50 hz which was also favored by their German affiliate, AEG. For decades afterward much of Southern California operate at 50 hz while rest of the nation would standardize on 60 hz

By 1936, Los Angeles Bureau of Power and Light (Now LADWP) converted to 60 hz in order to accept power from Boulder (Hoover) dam but it wasn't until 1945 when Southern California Edison began the conversion of its power and distribution network to 60 hz. Over the next three years, Southern California Edison brought out 60 hz power to its 765,000 (at the time) customers. Generating and distribution equipment were retrofitted and “clock exchange” depots where Edison customers could bring in their existing 50 hz appliances for modification or exchange were setup across the region. The eventual total consisted of about 475,000 clocks, 380,000 lighting fixtures, and 58,000 refrigerators. Converting to 60 hz costed Edison 34.4 million dollars but on October 27, 1948; Southern California Edison’s grid finally operated in unison with the rest of the nation.


Its been almost 69 years since Southern California Edison, the primary utility company for much of Southern California, completed the conversion to 60 hz alternating current but I wonder what would it be like if So. Cal was still on a 50 hz power grid. The prime example I could think of is Japan; the Eastern half of the country operates at 50 hz while the Western half operates at 60 hz.


 

Why do we run on 60Hz rather than 50Hz anyway?

From what I understand, Tesla, among others, recommended 220V and 60Hz as the world standard. A cycle of 60Hz makes it easier to calculate 3-phase systems. In North America, it was seen as a prudent move to lower the voltage to 110V for "safety" reasons. In Europe and many other countries, they kept the 220V and lowered the 60Hz to 50Hz for a very political reason : 50 more closely resembles the metric system than 60Hz. Now that the tradition is well established and that there are enormous amounts of appliances and machines that operate on electricity, it is way too difficult to change.

Note : 110V mains were augmented to 120V, and 220V mains were augmented to 230V in some places and 240V in others.

If it was possible, I would vote for 240V and 60Hz as a world wide standard.

+1

I think the only advantage with 120v is with incandescent filaments.


That and powercon true1 for connectors. Those things are awesome.

New York City had both direct current distribution and 25 Hertz distribution until just recently. Con-Edison generated 25 Hz. power for  rotary converter stations that supplied their direct current street network. All rotary converters were retired along with the associated 25 Hz. supply by 1977 and direct current was being supplied by rectifiers in street vaults. In 1977, there were still 12,000 direct current customers in Manhattan. By 2000,there were 5,000 direct current customers. Con-Edison embarked on a program to finally shut down it's direct current network. The Company gave the customers the choice of either installing rectifiers on the customers premises to supply existing DC equipment, or change all of the customers equipment to AC. In either case Con-Edison paid for the conversion. In 2007, after over 125 years, Con-Edison shut down their Direct Current network.
 Con-Edison also had a 25Hz supply for the rotary converters used by the New York City subway. The private companies that had originally constructed the subway had built three power plants that supplied 11,000 volt,25Hz to rotary converter stations located along the right of way. The City built its' own subway in the 1920's and 30's,but this system used commercial 60 Hz power to supply mostly mercury arc rectifiers located along the right of way. In 1940,the City purchased the privately run subways( the Interborough Rapid Transit Company, IRT, and the Brooklyn Manhattan Transit Company,BMT, and combined them with the Independent City Owned Subway,IND.)  By 1959, the power plants that the City had taken over from the IRT and BMT were badly in need of upgrading. The City chose to sell the plants to Con-Edison,with the understanding that the utility had to maintain the 25Hz supply for 40 years. The last rotary converter station on the NYC subway was retired in 1999.

Why do we run on 60Hz rather than 50Hz anyway?

60cy/sec happens to be a happy medium frequency for a lot of stuff like transformer design and transmission lines.  50cy/sec is worse, but not by enough to justify conversion of extant 50cy/sec systems.  Tesla and other early Westinghouse engineers actually recommended 133-1/3cy/sec and that is what was used for the Great Barrington Electrification.

From what I understand, Tesla, among others, recommended 220V and 60Hz as the world standard. A cycle of 60Hz makes it easier to calculate 3-phase systems. In North America, it was seen as a prudent move to lower the voltage to 110V for "safety" reasons. In Europe and many other countries, they kept the 220V and lowered the 60Hz to 50Hz for a very political reason : 50 more closely resembles the metric system than 60Hz. Now that the tradition is well established and that there are enormous amounts of appliances and machines that operate on electricity, it is way too difficult to change.

Note : 110V mains were augmented to 120V, and 220V mains were augmented to 230V in some places and 240V in others.

If it was possible, I would vote for 240V and 60Hz as a world wide standard.

At its core 120v power here is actually 240v.

It all comes from the geography and partly from history:
The 120V home service is a kind of residue of the Edison's DC power era. With DC, higher voltages become problematic to handle (mainly problems with quite persistent arcs), the 120V is really the maximum that can be reasonably dealt with in home like installation. And because in the US the electrification started quite large already with the DC systems, the 120V became quite wide spread. So it became easier to stick with that, at least for the home lighting (the main electricity use).
Most US consumers are spread across large area, so the "last mile" wiring (from the district distribution transformer to the consumers) is quite long, which made the direct use of the original Edison concept not that optimal.
That means even 220V would be too low voltage for that, the voltage in the wiring needs to be higher (in the kV range), so high it is unusable within a home or so. So it requires a dedicated transformer at each consumer.
Having transformer at the consumer, close to the loads means the lower voltage for the loads behind this transformer is not that problem anymore, the distances are short. Therefore the 2x120V/240 single phase remained till today.
And because this scheme means there are a ton of transformers, it was beneficial to operate the mains at a bit higher frequency - transformers becomes smaller, cheaper and more efficient. Therefore the 60Hz.
And because each consumer needed to have his own transformer, it would become quite expensive to use all 3 phases (except really high power customers, like commercial or larger appartments). Therefore everything is operated at a single phase, even when it means extra cost and reliability complications with motor capacitors and starters.
So the 2x120/240V single phase split phase system became the standard

On the contrary people in Europe tend to live "more densely packed" into clusters with large enough consumer base. That means the "last mile" of the distribution (from the distribution transformer; usually 22kV/400V) became way shorter, so using 3x230V/400V and feeding that directly to the homes become the preferred way.
And because the last mile run at lower voltage and higher currents (3x230V/400V instead of the few kV), very important factor is to keep the efficiency of these sections high enough. And that led to the preference of the lower frequency, hence the 50Hz
Another consequence was, for really high power loads (kVA and higher, mainly motors) it became very advantageous to use all 3 phases, as that just means splitting the wiring to 3 phases, because no customer transformer means no penalty for using all 3 phases. So unless it is some really small thing, most motor equipment just uses 3 phases straight away and no hassle with any complications like large motor capacitors and relays.
Hence the standard became the 3 phase 3x230/400V. Only very small customers where many of them are packed together in a single building (units within apartment complexes,...) use just a single phase service.

In early installations many places also started with 120V DC, but there were way less installations, usually not exceeding premises of a single factory or farm, so not that much customer base.
Then later a safety concept of "not that deadly" 70V vs ground became a thing as a way to protect people when a short circuit towards conductive case of an equipment happened. But I'm suspecting this became an afterthought of distributing 3 phase (3x70/)120V power, where the 120V, equal voltage to the earlier DC systems, was taken from between the phases.
And then there were two world wide wars sweeping Europe, both needing complete infrastructure rebuild from scratch, so there was not that much legacy systems left so it was an easier decision to go for a system better optimized for more modern needs.

And recently a lot of ELV DC systems are emerging across the globe, mainly in what is called the "3'rd world" - just because that becomes the easiest way for small isolated systems, usually run on solar power with batteries and powering lights and some IT (phones, personal computers, TV's,...). Running an inverter there means quite high idle power drain, so the main installation is directly at the DC battery level (usually 12, 24, 36 or 48V nominal), only when devices needing AC are used, the inverter is turned ON. This market becomes big enough so it gradually becomes standardized to a level that a lot of off the shelf equipment becomes available designed to run on them.
These are intended for very low income (per western standards) users, but there are quite a lot of such people to form quite significant customer base to justify things like standardization (it seems like the 48V and maybe also 24V).
Moreover unlike on AC, it is easier to design DC appliance that can run multiple voltage levels, like 24 till 48V, some low power ones even the whole 12..48V range...