5 ms·

I'm not sure what sort of smart meter integration is required to make this happen, but it would be sweet if the electric car could ramp down or pause it's charg

I'm not sure what sort of smart meter integration is required to make this happen, but it would be sweet if the electric car could ramp down or pause it's charging near-instantly when the induction stove or AC kicks on, since those are both intermittent and the car charging can wait.

brianwawok 4y ago
My EV lets me say "start charging at 11pm" My induction stove is never ever going to run at 11pm.
- nemo44x 4y ago
  But maybe you have a couple (or more!) AC units (or heat pumps) that both happen to kick in at the same time at 11pm by chance.
  - brianwawok 4y ago
    So 100amp service is a "normal" sized house. Your heat pump and AC are what, 30 amps? So it's ok if it kicks on at 11.
    - nemo44x 4y ago
      That's not really true. 200A has been sent to typical homes the last 30-40 years as our energy needs have increased. A normal sized home in America is 2,400-3,000 SqFt. which probably requires a couple AC units. Already if 2 units are going and the induction stove is running + whatever else in the house, you're already well over 100A. Now factor in that everything will trip at 80% so you don't even get your total load. I highly doubt a 100A system would pass code in the type of configuration you're suggesting. "Trust me, I'll run everything right" isn't good enough. I'd be shocked your 100A panel even has any space left for a new 30A+ circuit.
      - brianwawok 4y ago
        > A normal sized home in America is 2,400-3,000 SqFt. which probably requires a couple AC units I don't understand where you are getting this multiple AC unit thing. My house is 4,700 square feet above grade (2000 more below grade), and I have a single AC. Now it is the absolute biggest, baddest, mode insane residential AC unit my HVAC place makes (5 ton seer 27 I believe).. but it is a single unit. I think I know a single person who has 2 AC units, and their house is a bit smaller than mine (maybe 4500 square feet). If my house were built today it would have 2 ACs.. but again, I am very much on the extreme end of size. And this entire thing is on I believe a 40 amp circuit.
        nemo44x 4y ago
        There are millions of old homes that need to be retrofitted for AC. They don’t have duct work because they are heated by radiators. When they are upgraded to have AC they often have 2 (or more) units since running ducts up and down isn’t feasible. So for the first floor you run ducts in the basement and vent up. For second the coil is in the attic if possible and vent down. These types of homes often have 100A service and running 3t + 2t already stress it. People also do it for efficiency reasons. Running hot/cold air long distances is a good way to waste money. It’s also better design to have multiple units and therefore multiple zones. Why are you cooling your bedrooms all day and your living room all night? Installing multiple units is better design but cheap builders just try and keep prices/quotes low to customers that don’t understand it.
AYBABTME 4y ago
A battery would help here to handle the surge. At least that's how I've got it setup on my boat, where my inverters supplement the limited 30A "service" by pulling from the battery when the load goes above 30A.
zamnos 4y ago
The feeders off the meter just need their own power meter and some smarts and a way to tell the car to pause charging (or just deenergize that circuit). The smarts monitor the circuit that goes to the kitchen, sees that there's been a significant power draw for some amount of time, and then shuts off the car charging circuit. Pretty straightforwards circuit to build from scratch, though I'd recommend just getting a unit that does that.

brianwawok 4y ago

My EV lets me say "start charging at 11pm" My induction stove is never ever going to run at 11pm.

nemo44x 4y ago
But maybe you have a couple (or more!) AC units (or heat pumps) that both happen to kick in at the same time at 11pm by chance.
- brianwawok 4y ago
  So 100amp service is a "normal" sized house. Your heat pump and AC are what, 30 amps? So it's ok if it kicks on at 11.
  - nemo44x 4y ago
    That's not really true. 200A has been sent to typical homes the last 30-40 years as our energy needs have increased. A normal sized home in America is 2,400-3,000 SqFt. which probably requires a couple AC units. Already if 2 units are going and the induction stove is running + whatever else in the house, you're already well over 100A. Now factor in that everything will trip at 80% so you don't even get your total load. I highly doubt a 100A system would pass code in the type of configuration you're suggesting. "Trust me, I'll run everything right" isn't good enough. I'd be shocked your 100A panel even has any space left for a new 30A+ circuit.
    - brianwawok 4y ago
      > A normal sized home in America is 2,400-3,000 SqFt. which probably requires a couple AC units I don't understand where you are getting this multiple AC unit thing. My house is 4,700 square feet above grade (2000 more below grade), and I have a single AC. Now it is the absolute biggest, baddest, mode insane residential AC unit my HVAC place makes (5 ton seer 27 I believe).. but it is a single unit. I think I know a single person who has 2 AC units, and their house is a bit smaller than mine (maybe 4500 square feet). If my house were built today it would have 2 ACs.. but again, I am very much on the extreme end of size. And this entire thing is on I believe a 40 amp circuit.
      - nemo44x 4y ago
        There are millions of old homes that need to be retrofitted for AC. They don’t have duct work because they are heated by radiators. When they are upgraded to have AC they often have 2 (or more) units since running ducts up and down isn’t feasible. So for the first floor you run ducts in the basement and vent up. For second the coil is in the attic if possible and vent down. These types of homes often have 100A service and running 3t + 2t already stress it. People also do it for efficiency reasons. Running hot/cold air long distances is a good way to waste money. It’s also better design to have multiple units and therefore multiple zones. Why are you cooling your bedrooms all day and your living room all night? Installing multiple units is better design but cheap builders just try and keep prices/quotes low to customers that don’t understand it.

AYBABTME 4y ago

A battery would help here to handle the surge. At least that's how I've got it setup on my boat, where my inverters supplement the limited 30A "service" by pulling from the battery when the load goes above 30A.

zamnos 4y ago

The feeders off the meter just need their own power meter and some smarts and a way to tell the car to pause charging (or just deenergize that circuit). The smarts monitor the circuit that goes to the kitchen, sees that there's been a significant power draw for some amount of time, and then shuts off the car charging circuit. Pretty straightforwards circuit to build from scratch, though I'd recommend just getting a unit that does that.