4 ms·

Split phase means we get the choice of 120V (for safety) and 240V when we really need it (eg appliances)

jabl 4y ago
Where I live it's fairly common for houses to have 230V single phase for most things, and then 400V three phase for things needing more power.
petre 4y ago
How do you resolve phase imbalances? Most generators are 3 phase. The system is othrewise well designed to use one or two phases when needed. We use one or three phass in Europe.
- eru 4y ago
  Different circuits in a single American household use different phases, I think.
  - Scoundreller 4y ago
    Correct. Fun times trying to figure out why your power-line networking doesn't work. The heavy load stuff is 240V anyway.
  - petre 4y ago
    So it's the same way we do it in Europe with single phase, but I think it's easier to split three phases between single phase loads (most AC loads in a hosehold), rather than three phases between two phase loads (a few AC loads in a household). I still like the 120V plug connector with a key on the hot wire. In Europe I always wire the hot on the right hand side of the Schuko socket, as most standards have it on the right.
    - eru 4y ago
      American outlets and plugs are barely usable. They go live even when you don't completely plug them in, yet. The British plug is a pretty decent design from an electrical safety point of view. (However, they turn into caltrops in the dark.)
      - petre 4y ago
        > The British plug is a pretty decent design from an electrical safety point of view It's needlessly huge. I like type J (SN 441011, Swiss plug) and type N (IEC 60906-1, South Africa).
        eru 4y ago
        Yes, both of those would also work. It's just that the American plugs are really the worst. See also https://www.youtube.com/watch?v=K_q-xnYRugQ https://www.youtube.com/watch?v=K_q-xnYRugQ for other badness.
Scoundreller 4y ago
Unless you're in a condo/apartment building where it's often 208V, not 240V. Kinda annoying when your "208V/240V" dryer puts out 25% less heat.
- jsjohnst 4y ago
  > Unless you're in a condo/apartment building where it's often 208V, not 240V. 208V (vs 220/230/240V) has minimal to do with it being a condo and everything to do with the type of incoming power. 208V is from taking two phases of a 120V three phase service. One phase to ground, 120V, phase to phase, 208V. For the alternative voltage (named 220/230/240V depending on context), the incoming power to the transfer is a single phase. The transformer then produces a split phase 220/230/240V where each phase is 180° opposite each other. The only reason you _might_ see it more frequently at a condo/apartment is due to there being a need or desire for 3 phase power.
  - Scoundreller 4y ago
    At least around here, condos/apartments will have big elevator, water pump and HVAC motors and therefore prefer 3ph, so 208V is the "rule" rather than the exception. Where it gets a little funny is that the Canadian standard for "industrial" power is 600V, not 480V, and that can make it hard to find replacements in some larger buildings with custom requirements.
    - jsjohnst 4y ago
      > At least around here, condos/apartments will … so 208V is the "rule" rather than the exception Yeah, didn’t mean to imply it was unusual, just explaining for others that it’s not a quirk of condos/apartments specifically. > Where it gets a little funny is that the Canadian standard for "industrial" power is 600V, not 480V Speaking of 480V, you ever dealt with 277V much? That’s a real “fun” voltage to be around when something goes wrong. :(
      - Scoundreller 4y ago
ReptileMan 4y ago
I am not sure that Western Europe is objectively worse at the safety department than us. Also you can always put a smaller breaker on 240. The 120V in the US is a 640kb ram should be enough situation. You were first, thought you build the spare capacity, were surprised by the explosive growth and how useful electricity really is. With modern homes moving to 100% electricity even 240 is not enough. In my flat I have pizza oven (3kw),inducation burner x 2 (3kw each), normal oven, 12000 btu AC x 2, tumble dryer, some other appliances that chug sub 1k... throw in some car charging, electrical water heater... A modern home is using orders of magnitude more electricity. And it is going up.
- sokoloff 4y ago
  Orders of magnitude more? 2 base 2 orders of magnitude perhaps, but not 100x more…
- manfre 4y ago
  You seem to be confusing voltage as the unit that dictates electrical load. Voltage x Amps is what dictates how many electrical devices you can use at the same time. Residential voltage is fixed at 120 or 240 with no chance of changing in our lifetimes. As homes need more power, they are delivered more amps. The common for newer construction in the US is 240V at 200 amp or 400 amp for larger homes. Older homes will have anywhere from 80-150A depending on when they were built or remodeled enough to require replacing the main service panel. Stove, HVAC, and dryer require their own dedicated 240V circuits.
  - ReptileMan 4y ago
    I have not confused anything. The idea is that powerful applliences require more copper and bigger gauges for lower voltages (not linear). And we have more if them. So by upping the voltage we can save on the wiring. In eu you don't have to think where to plug 2.5 kw space heater. Any outlet is good enough. In the US you have to. And with home appliances actually becoming bigger and more powerful I think that even the EU baseline will become too constraining eventually. Since usually there are limitation on the gauges that are ran from the main breaker to the sub-breakers (don't know english electric jargon) Where I live I have a wire that can hold I think 40 amps in the wall from the main breaker to the board where the small breakers terminate the different home circuts. If I want to upgrade it is dig baby dig. 6 floors.

jabl 4y ago

Where I live it's fairly common for houses to have 230V single phase for most things, and then 400V three phase for things needing more power.

petre 4y ago

How do you resolve phase imbalances? Most generators are 3 phase. The system is othrewise well designed to use one or two phases when needed. We use one or three phass in Europe.

eru 4y ago
Different circuits in a single American household use different phases, I think.
- Scoundreller 4y ago
  Correct. Fun times trying to figure out why your power-line networking doesn't work. The heavy load stuff is 240V anyway.
- petre 4y ago
  So it's the same way we do it in Europe with single phase, but I think it's easier to split three phases between single phase loads (most AC loads in a hosehold), rather than three phases between two phase loads (a few AC loads in a household). I still like the 120V plug connector with a key on the hot wire. In Europe I always wire the hot on the right hand side of the Schuko socket, as most standards have it on the right.
  - eru 4y ago
    American outlets and plugs are barely usable. They go live even when you don't completely plug them in, yet. The British plug is a pretty decent design from an electrical safety point of view. (However, they turn into caltrops in the dark.)
    - petre 4y ago
      > The British plug is a pretty decent design from an electrical safety point of view It's needlessly huge. I like type J (SN 441011, Swiss plug) and type N (IEC 60906-1, South Africa).
      - eru 4y ago
        Yes, both of those would also work. It's just that the American plugs are really the worst. See also https://www.youtube.com/watch?v=K_q-xnYRugQ https://www.youtube.com/watch?v=K_q-xnYRugQ for other badness.

Scoundreller 4y ago

Unless you're in a condo/apartment building where it's often 208V, not 240V. Kinda annoying when your "208V/240V" dryer puts out 25% less heat.

jsjohnst 4y ago
> Unless you're in a condo/apartment building where it's often 208V, not 240V. 208V (vs 220/230/240V) has minimal to do with it being a condo and everything to do with the type of incoming power. 208V is from taking two phases of a 120V three phase service. One phase to ground, 120V, phase to phase, 208V. For the alternative voltage (named 220/230/240V depending on context), the incoming power to the transfer is a single phase. The transformer then produces a split phase 220/230/240V where each phase is 180° opposite each other. The only reason you _might_ see it more frequently at a condo/apartment is due to there being a need or desire for 3 phase power.
- Scoundreller 4y ago
  At least around here, condos/apartments will have big elevator, water pump and HVAC motors and therefore prefer 3ph, so 208V is the "rule" rather than the exception. Where it gets a little funny is that the Canadian standard for "industrial" power is 600V, not 480V, and that can make it hard to find replacements in some larger buildings with custom requirements.
  - jsjohnst 4y ago
    > At least around here, condos/apartments will … so 208V is the "rule" rather than the exception Yeah, didn’t mean to imply it was unusual, just explaining for others that it’s not a quirk of condos/apartments specifically. > Where it gets a little funny is that the Canadian standard for "industrial" power is 600V, not 480V Speaking of 480V, you ever dealt with 277V much? That’s a real “fun” voltage to be around when something goes wrong. :(
    - Scoundreller 4y ago

ReptileMan 4y ago

I am not sure that Western Europe is objectively worse at the safety department than us. Also you can always put a smaller breaker on 240. The 120V in the US is a 640kb ram should be enough situation. You were first, thought you build the spare capacity, were surprised by the explosive growth and how useful electricity really is. With modern homes moving to 100% electricity even 240 is not enough. In my flat I have pizza oven (3kw),inducation burner x 2 (3kw each), normal oven, 12000 btu AC x 2, tumble dryer, some other appliances that chug sub 1k... throw in some car charging, electrical water heater... A modern home is using orders of magnitude more electricity. And it is going up.

sokoloff 4y ago
Orders of magnitude more? 2 base 2 orders of magnitude perhaps, but not 100x more…
manfre 4y ago
You seem to be confusing voltage as the unit that dictates electrical load. Voltage x Amps is what dictates how many electrical devices you can use at the same time. Residential voltage is fixed at 120 or 240 with no chance of changing in our lifetimes. As homes need more power, they are delivered more amps. The common for newer construction in the US is 240V at 200 amp or 400 amp for larger homes. Older homes will have anywhere from 80-150A depending on when they were built or remodeled enough to require replacing the main service panel. Stove, HVAC, and dryer require their own dedicated 240V circuits.
- ReptileMan 4y ago
  I have not confused anything. The idea is that powerful applliences require more copper and bigger gauges for lower voltages (not linear). And we have more if them. So by upping the voltage we can save on the wiring. In eu you don't have to think where to plug 2.5 kw space heater. Any outlet is good enough. In the US you have to. And with home appliances actually becoming bigger and more powerful I think that even the EU baseline will become too constraining eventually. Since usually there are limitation on the gauges that are ran from the main breaker to the sub-breakers (don't know english electric jargon) Where I live I have a wire that can hold I think 40 amps in the wall from the main breaker to the board where the small breakers terminate the different home circuts. If I want to upgrade it is dig baby dig. 6 floors.