3 ms·

The UK plug is honestly one of the best things the UK has ever done. It's reliable, hard to pull out via the cable, running at a sensible voltage, and they just

The UK plug is honestly one of the best things the UK has ever done. It's reliable, hard to pull out via the cable, running at a sensible voltage, and they just feel so sturdy. Rectangular contacts also hold a grip much better than round ones (in America and friends). I've heard horror stories about American plug sockets. It's just way too easy to shock yourself. And then you have all the other weirdness, like 240V on the grid being stepped down for 120V for appliances. Wouldn't it be easier (and more energy-efficient), to use 240V instead of stepping it down and having to pull more current at the appliance level to make up for the voltage?

jakedata 5y ago
Here in the states we do not step 240v down to 120v. Typically a home has 240v split-phase service with 240v available L1 to L2 and 120v by using L1 or L2 to neutral. Our circuit breaker panels alternate L1 and L2 bus connections internally so a column of single breakers will alternate between L1 and L2 for balance while a double breaker will get 240v by connecting to both busses. A 240v double breaker has a physical connection between the trip levers so that an overload on either leg will trip both.
- kruador 5y ago
  Relevant video: Technology Connections, "The US electrical system is not 120V", where there is a (long) discussion of how the breaker panel works and how you get 240V. https://www.youtube.com/watch?v=jMmUoZh3Hq4 https://www.youtube.com/watch?v=jMmUoZh3Hq4
  - teddyh 5y ago
    By the same definition, the European electrical system is not 240V, it’s 380V.
    - frosted-flakes 5y ago
      Europe does not have split phase electrical service. Three-phase service is ultimately how the US system works, same as Europe; it's just that entire neighbourhoods or streets will run off a single 240 V phase rather than each house getting all three phases (industrial buildings commonly have three-phase service).
      - jacquesm 5y ago
        > Europe does not have split phase electrical service. This is incorrect in many places. Yes, you will have three phase electrical service pulled right into the distribution panel, but in many places all you will receive is a single phase because only one of the three possible fuses is installed. If you want three phase hookup you just pay your utility company a small fee, they come out to install the extra two fuses and in some cases they'll upgrade your consumption meter to three phase. > Three-phase service is ultimately how the US system works, same as Europe; it's just that entire neighbourhoods or streets will run off a single 240 V phase rather than each house getting all three phases (industrial buildings commonly have three-phase service). In the US plenty of the last leg of the distribution network is single phase, in the EU it is almost everywhere three phase, except for some rural areas in former East block countries. Typically a step down transformer will take the distribution voltage and reduce it to something the residents can use directly, houses are then alternating in which of the three fuses is placed (R/S/T) to ensure relatively even distribution of the load. Here you see a three phase domestic hookup (for instance because of an electric range): https://www.superflink.nl/media/wysiwyg/1-of-3-fase-aansluiting.superflink-groepenkasten.jpg https://www.superflink.nl/media/wysiwyg/1-of-3-fase-aansluit... and here a single phase one: https://www.circuitsonline.net/forum/file/58210/forum-post https://www.circuitsonline.net/forum/file/58210/forum-post In this case the 'S' leg of the transformer is used to power the dwelling.
        frosted-flakes 5y ago
        What you describe is not split phase. Split phase is where one 240V phase is split into two 120V legs offset 180°, with a center-tapped 0V neutral.
    - jacquesm 5y ago
      This is an incorrect interpretation of the differences between the two systems. In the EU the 380V (now nominally 400V) relates to tri-phase, the 240V to the voltage between a phase and ground. Tri-phase power in the United States is available to residential consumers and very light industry (say a small farm) at a number of different voltages up to 480V. The 240V in the united states is between two 'lives' that are both 120V and that are usually delivered on a center tapped transformer with the center being the neutral. Adding those two together gives you the 240V, but it all comes from a single phase, it's just a center tapped transformer with a 240V winding as the secondary. You can easily see this when you look at your typical drop transformer that will take a 10KV low voltage distribution line to domestic voltages, where three phase power is required you'll see three transformers in a bank, one for each phase. A typical residence will have only one because in North America single phase power is the norm for distribution. https://www.mytpu.org/wp-content/uploads/wires.jpg https://www.mytpu.org/wp-content/uploads/wires.jpg Is pretty typical in NA. So a typical drop will have a distribution neutral and a single distribution phase going in to the transformer and three wires coming back out: L1, N and L2 with L1 and L2 being the outside legs of the winding. In your distribution panel you then add your residential ground.
      - jacquesm 5y ago
        bugfix: the 240V to the voltage between a phase and ground This is possible, but more likely is a phase-to-phase in a delta configured transformer. In that case there is no ground delivered to the distribution panel, just two phases (or three).
- tentacleuno 5y ago
  > Here in the states we do not step 240v down to 120v. Typically a home has 240v split-phase service with 240v available L1 to L2 and 120v by using L1 or L2 to neutral. Ahh, thank you! I should have checked that point more thoroughly.

jakedata 5y ago

Here in the states we do not step 240v down to 120v. Typically a home has 240v split-phase service with 240v available L1 to L2 and 120v by using L1 or L2 to neutral. Our circuit breaker panels alternate L1 and L2 bus connections internally so a column of single breakers will alternate between L1 and L2 for balance while a double breaker will get 240v by connecting to both busses. A 240v double breaker has a physical connection between the trip levers so that an overload on either leg will trip both.

kruador 5y ago
Relevant video: Technology Connections, "The US electrical system is not 120V", where there is a (long) discussion of how the breaker panel works and how you get 240V. https://www.youtube.com/watch?v=jMmUoZh3Hq4 https://www.youtube.com/watch?v=jMmUoZh3Hq4
- teddyh 5y ago
  By the same definition, the European electrical system is not 240V, it’s 380V.
  - frosted-flakes 5y ago
    Europe does not have split phase electrical service. Three-phase service is ultimately how the US system works, same as Europe; it's just that entire neighbourhoods or streets will run off a single 240 V phase rather than each house getting all three phases (industrial buildings commonly have three-phase service).
    - jacquesm 5y ago
      > Europe does not have split phase electrical service. This is incorrect in many places. Yes, you will have three phase electrical service pulled right into the distribution panel, but in many places all you will receive is a single phase because only one of the three possible fuses is installed. If you want three phase hookup you just pay your utility company a small fee, they come out to install the extra two fuses and in some cases they'll upgrade your consumption meter to three phase. > Three-phase service is ultimately how the US system works, same as Europe; it's just that entire neighbourhoods or streets will run off a single 240 V phase rather than each house getting all three phases (industrial buildings commonly have three-phase service). In the US plenty of the last leg of the distribution network is single phase, in the EU it is almost everywhere three phase, except for some rural areas in former East block countries. Typically a step down transformer will take the distribution voltage and reduce it to something the residents can use directly, houses are then alternating in which of the three fuses is placed (R/S/T) to ensure relatively even distribution of the load. Here you see a three phase domestic hookup (for instance because of an electric range): https://www.superflink.nl/media/wysiwyg/1-of-3-fase-aansluiting.superflink-groepenkasten.jpg https://www.superflink.nl/media/wysiwyg/1-of-3-fase-aansluit... and here a single phase one: https://www.circuitsonline.net/forum/file/58210/forum-post https://www.circuitsonline.net/forum/file/58210/forum-post In this case the 'S' leg of the transformer is used to power the dwelling.
      - frosted-flakes 5y ago
        What you describe is not split phase. Split phase is where one 240V phase is split into two 120V legs offset 180°, with a center-tapped 0V neutral.
  - jacquesm 5y ago
    This is an incorrect interpretation of the differences between the two systems. In the EU the 380V (now nominally 400V) relates to tri-phase, the 240V to the voltage between a phase and ground. Tri-phase power in the United States is available to residential consumers and very light industry (say a small farm) at a number of different voltages up to 480V. The 240V in the united states is between two 'lives' that are both 120V and that are usually delivered on a center tapped transformer with the center being the neutral. Adding those two together gives you the 240V, but it all comes from a single phase, it's just a center tapped transformer with a 240V winding as the secondary. You can easily see this when you look at your typical drop transformer that will take a 10KV low voltage distribution line to domestic voltages, where three phase power is required you'll see three transformers in a bank, one for each phase. A typical residence will have only one because in North America single phase power is the norm for distribution. https://www.mytpu.org/wp-content/uploads/wires.jpg https://www.mytpu.org/wp-content/uploads/wires.jpg Is pretty typical in NA. So a typical drop will have a distribution neutral and a single distribution phase going in to the transformer and three wires coming back out: L1, N and L2 with L1 and L2 being the outside legs of the winding. In your distribution panel you then add your residential ground.
    - jacquesm 5y ago
      bugfix: the 240V to the voltage between a phase and ground This is possible, but more likely is a phase-to-phase in a delta configured transformer. In that case there is no ground delivered to the distribution panel, just two phases (or three).
tentacleuno 5y ago
> Here in the states we do not step 240v down to 120v. Typically a home has 240v split-phase service with 240v available L1 to L2 and 120v by using L1 or L2 to neutral. Ahh, thank you! I should have checked that point more thoroughly.