Most of the wiring used at the res level (Romax) is rated for 300 VAC and allot of the time 600VAC, so to use 240vac to outlets is not that much of a change. You would have the Red and Black for the outlets two sides and bare ground for, well, a ground. Both sides however would be hot which does pose safety concerns. You touch either side and a ground and OUCH!!. The real change would have to come at the loads themselves. That would roughly half the current load, so you 14AWG for a 15A circuit could drop a ~16AWG or so for equal power.
And then there is the whole DC side changing to three phase AC for the loads electronically and any number of other ways to configure. To be blunt, the whole thing could be a giant mess creating allot of confusion, for an undetermined amount of actual "metal" savings and increased safety risk.
Probably the best way is to 240VAC for inductive and high resistive loads (Electric dryer, electric water heater, EV charger, etc. and PoA DC for regular lighting and low power loads. Where I have an issue with that though is all the intermediate inductive loads for outlets like kitchen loads, mixers, blenders, microwaves,... on and on. Then there is the "workshop" power tools mid range inductive loads, table saws, radial saws, drills, saw zaws, routers, skill saws, ..... etc.. You really have to separate lighting from everything else, which could be done with PoA.. to a point of a couple of hundred watts.
As I said, messy though....
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william fitch
Owner
www.WeAreSolar.com------------------------------
Original Message:
Sent: 11-09-2022 04:56 PM
From: Joel Dunn
Subject: Zoom Discussion - Preparing for your Electric Vehicle: Will 400 Amp service be the new normal?
Interesting, William!
So with respect to the voltage, are you saying 240 everywhere as in most of the rest of the world, or were you talking about higher voltage on heavy circuits?
The idea of hybrid DC and AC in a house is intriguing it sorta makes sense as we have more electronics…
-Joel
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Joel Dunn
Joel Dunn
Original Message:
Sent: 11-09-2022 02:18 PM
From: william fitch
Subject: Zoom Discussion - Preparing for your Electric Vehicle: Will 400 Amp service be the new normal?
Hi Joel: I pretty much agree with your position, but the thought for 400A as a norm, partially revolves around having enough when the 1% need arises, perhaps in an un-opportune situation. At the same time (Now) there is a push for PoE and low voltage wiring to become the norm to allow for reduced copper usage in wiring, being cognocent of our limited Cu resources, etc..
As is not unusual, these two agendas are contradictory to each other. You cannot have you cake and eat it to. The only way this can even be a twin workable outcome, is if the standard wiring in a house by the foot, is reduced in size for all the new small loads PoE type, and putting in special high power circuits for those devices as needed. This I think is where the DC/AC wiring house specifications come into play. We kind of have that now to a degree in the USA wiring using 120VAC for "normal" loads and 240VAC for the "heavy" stuff as listed in other posts. The easiest way to increase power and not increase Cu or Al usage is to increase voltage. However, this of course raises the danger of the energy to the end user..... Always choices....
I have in the past been across a 120vac circuit with the appropriate swearing, 240vac is more of a wake up and feel your body event...
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william fitch
Owner
www.WeAreSolar.com
Original Message:
Sent: 11-09-2022 12:40 PM
From: Joel Dunn
Subject: Zoom Discussion - Preparing for your Electric Vehicle: Will 400 Amp service be the new normal?
Thinking that 400 amps is required really misunderstands EV charging. I have been driving EVs for 5 years, and I currently have a 2020 Bolt and a Rivian R1T. We rarely charge at higher than 24 amps (I have a 40 amp JuiceBox on a 50 amp circuit, on a 200 amp service). Often we charge at 12 to 16 amps to match excess solar production (we are grid tied zero export self consumption; solar config is 7.67 kW with 2 Powerwalls, one 2018 and one 2022).
We charge to 100% only if going on a trip, and normally keep the vehicles at 30 to 70%. We charge based on upcoming driving requirements. Do you always keep the gas tank completely full in an ICE vehicle? Unless someone is driving 200+ miles a day, there's little need for maximum charge rate to the car, and even then, a 40 amp EVSE will meet most needs.
Also, what are the other high loads? Other than the high instantaneous locked rotor amps (LRA) to start heat pumps what do you need? The running load amps (RLA) is maybe 10 to 30 depending on the size. How many heat pumps do you have? An electric water heater is 30 amps for a traditional one, not a heat pump water heater. My laundry center is now an "all-in-one" that is ventless and runs on a 20 amp 120V circuit. A electric oven is 30? Maybe a hot tub or pool heater? Even with an EV or two, I don't see 400 except for a huge house.
Caveat…I'm a retired computer scientist, not an electrical engineer!
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Joel Dunn
Original Message:
Sent: 11-08-2022 11:54 AM
From: william fitch
Subject: Zoom Discussion - Preparing for your Electric Vehicle: Will 400 Amp service be the new normal?
Your title gave me the thought that 400A may be the new to come charging infrastructure delivery, but the cars on average won't be able to handle it. Reminds me of I.T back in the 90's regarding hardware and software. If you think of the charging infrastructure as the computer processors and the EV's as the OS (Operating Systems), there was a time when the "Hardware" far out paced the Software. In short the processors could deliver far more than the software could take. Maybe the next 5 to 10 years in this system's duo, will play the same back and forth game.
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william fitch
Owner
www.WeAreSolar.com
Original Message:
Sent: 11-08-2022 11:09 AM
From: Jay Warmke
Subject: Zoom Discussion - Preparing for your Electric Vehicle: Will 400 Amp service be the new normal?
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Jay Warmke
Owner
Blue Rock Station LLC
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