Help me understand a home charging setup

ajdelange

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I'll start by noting that the grizzi charger linked to in the last post clearly plugs in and delivers up to 10 kW to one car. It can't do that in compliance with the code because it would have to draw 41.7 A from a 14-50R and under code it is limited to 40. That's not the thing I really want to emphasize in this post but it is illustrative of what I'm after here.

So let's go on to more elaborate schemes that involve charging more than one vehicle. What can you expect to be able to do in this regard with the service you have? I'm an engineer and I can't answer that question. Who can? An electrician familiar with the code and, more important, familiar with the way the local inspectors interpret it a large part of which is, of course, familiarity with the local inspectors. My electrician took this to extremes by getting his son a job as an inspector but that's not necessary (and he can't inspect any of Alan's work which I am sure you are all happy to hear) but if I tell him I want to do something he knows whether it will fly or not. This familiarity is 2 way. Your success is dependent on the inspectors knowing the electrician too. They know whose work they can be confident in and whose they can't. This all comes down to the necessity of finding a good electrician and getting him on board early. I wish I had an easy formula for finding a good electrician but I don't. You just have to keep looking til you find one and hope the search isn't punctuated by too many disasters.
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BigSkies

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All good info. Thanks everyone! I've been overthinking this a lot, and the end result will clearly be determined by how much room an electrician says I have.

I have an added complication that the easiest route to run wire is from a 100A sub-panel that is either maxed out, or close to it. Running it from my main panel will involve a trench and running wire underneath a paver pathway (since I don't want to run conduit all over the side of my house).

I'm not super stressed about adding the max amperage possible. In fact, I'd be plenty happy with a 40A circuit for the car, if I can run a dedicated 15A circuit for my dust collector at the same time. A typical day for us involves less than 10 miles of driving, with a couple days a month that involve much longer trips.

The "Duo" charger does look neat, and is aparently on in identical production schedule to Rivian ("available soon").

I think my path forward will be to get a quote from an electrician and to see what size circuit is available, and worry about the actual charger once I decide on the car.
 

SeaGeo

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I'll start by noting that the grizzi charger linked to in the last post clearly plugs in and delivers up to 10 kW to one car. It can't do that in compliance with the code because it would have to draw 41.7 A from a 14-50R and under code it is limited to 40.
Their manual basically defers to local ordinances and says you need to hardware if you go above 40. I have a chargepoint flex that can go up to 48 amp as well. One of, if not both, shipped with a plug and allow the installer to reduce their "rating". The grizzl-e does that via switches on the board inside the case. Whether that stricky follows code is their issue, but they do provide the tools to protect the circuit and keep it "inaccessible" to everyday consumer.

That and they clearly say it only goes up to 40A. I'm guessing they say up to 10kw by accounting to the upper voltage variability if the standard 240 connection. Or just rounding from 9.6.
 
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flabyboy

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You can install it and comission it for a 50A circuit in which case it will allow the truck to take up to 40A. Or you can install a 14-50R and plug in EVSE that allows the car to take 40A.
I plan on having him put a 50 Amp circuit in and use 6 gauge copper wire. You think I would be okay running it as high as 40amps? I don’t want to trip the breaker on the main supplying the garage. We have a chest freezer, lights and garage door opener. Not sure what would happen if all 4 were drawing power at the same time
 

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I second what most people have noted. ...
great suggestions. One more thing, most people only drive 20 miles a day. I have just used a regular 120v outlet. Overnight in a tesla model S I get about 48 miles of range added, so I effectively have a full tank every day even though it's this wimpy amount of power. On rare occasions when I drive a couple 100 miles, I still get 50 more and over a few nights I'm back up to full (about 235 / 265 full amount). If I was driving 150 miles every day I'd get a higher power charger, but I do have a supercharger nearby. For the rivian, since it's a bigger vehicle and unsurprisingly will take a little more power to charge, ie won't charge quite as many miles of range per unit of power, it might be that 120v isn't enough. When my rivian comes, I'll probably start out at 120v and see how frustrating that is.
 

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Their manual basically defers to local ordinances and says you need to hardware if you go above 40. I have a chargepoint flex that can go up to 48 amp as well. One of, if not both, shipped with a plug and allow the installer to reduce their "rating". The grizzl-e does that via switches on the board inside the case. Whether that stricky follows code is their issue, but they do provide the tools to protect the circuit and keep it "inaccessible" to everyday consumer.

That and they clearly say it only goes up to 40A. I'm guessing they say up to 10kw by accounting to the upper voltage variability if the standard 240 connection. Or just rounding from 9.6.
the Rivian Wall charger has the same ability to reduce the rating
 

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A little off topic, but since we seem to have experts here I have a quick question. I am in a house that does not allow the installation of a charger. I was looking at the dryer/washer splitter that automatically shuts off when you use the appliance. Is that my best bet when I need a big charge? Obviously if I have time I will just plug it into a normal outlet in the garage. While it is a PITA at least I don't pay for electricity here!
 

ajdelange

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You mean the "Dryer Buddy"? Seems like a pretty nifty solution to your problem but I have never seen one or talked to anyone who has.
 

WrekEE

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I paid an electrician for a 120amp subpanel in the garage for 2 EVs. I currently have a Jeep 4xe and bought a Grizzl-E charger. It will be nice if we can get away with only one charger but have room for 2.
 

ajdelange

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More that that. You could have put up to 6 of the old style HPWC on that subpanel and you can probably put more of the newer ones. They'll have to share though.
 

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Someone help me figure out what that rocker thing is in the middle here. This is a photo of my neighbors set up. The breaker on the left goes to his hardwired Tesla wall charger. The breaker on the right goes to a NEMA 14-50 outlet.

This is the setup I want so I can have a large plug and a charger, just not at the same time.

Also, he should have a 50 amp breaker on the right, right?
IMG_1416.jpeg
 

ajdelange

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That doodad is in there to prevent the breaker on the right being on if the breaker on the left is and conversely. It represents your neighbor's attempt at load sharing. Whenever the 14-50 is energized his HPWC is not. Thus, if someone came to visit with another Tesla his friend could not charge from the 14-50 using his UMC while your neighbor charged with the HPWC.

This is a sub panel which is fed from a breaker on the main panel. The object is to prevent the breaker on the main panel from tripping. An inspector might have required this device in order to pass the installation.

No, a 50A breaker is not required for the 14-50R. 40A is kosher. This is an exception in the code and is the reason the Telsa UMC limits current to 32A when the 14-50 adapter is used.
 

nfrank

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That doodad is in there to prevent the breaker on the right being on if the breaker on the left is and conversely. It represents your neighbor's attempt at load sharing. Whenever the 14-50 is energized his HPWC is not. Thus, if someone came to visit with another Tesla his friend could not charge from the 14-50 using his UMC while your neighbor charged with the HPWC.

This is a sub panel which is fed from a breaker on the main panel. The object is to prevent the breaker on the main panel from tripping. An inspector might have required this device in order to pass the installation.

No, a 50A breaker is not required for the 14-50R. 40A is kosher. This is an exception in the code and is the reason the Telsa UMC limits current to 32A when the 14-50 adapter is used.
I understand what that doodad is doing, I just want to know how to buy one myself. What is it called? Where do they sell it? How can I buy one?
 

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I understand what that doodad is doing, I just want to know how to buy one myself. What is it called? Where do they sell it? How can I buy one?
Doodads are next to the thingamabobs and doohickies at home depot. Sprockets are in the next asile.
 

xyskis

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All good info. Thanks everyone! I've been overthinking this a lot, and the end result will clearly be determined by how much room an electrician says I have.

I have an added complication that the easiest route to run wire is from a 100A sub-panel that is either maxed out, or close to it. Running it from my main panel will involve a trench and running wire underneath a paver pathway (since I don't want to run conduit all over the side of my house).

I'm not super stressed about adding the max amperage possible. In fact, I'd be plenty happy with a 40A circuit for the car, if I can run a dedicated 15A circuit for my dust collector at the same time. A typical day for us involves less than 10 miles of driving, with a couple days a month that involve much longer trips.

The "Duo" charger does look neat, and is aparently on in identical production schedule to Rivian ("available soon").

I think my path forward will be to get a quote from an electrician and to see what size circuit is available, and worry about the actual charger once I decide on the car.
I think this is a good idea. I would also just start with a simple drop-down NEMA 14-50 from your subpanel and go from there. You’re not out a whole bunch of money thinking about configurations and power draws for the two EVs you don’t yet have. Drop-down 14-50 should run you $100, $200 if the electrician is really milking it.

I had a Gen 3 Tesla HPWC installed and they’re supposed to communicate with other Tesla wall chargers to limit current and load share under simultaneous load. However, the multiple charging ecosystem is still quite young/expensive and I think we’ll start to see more cost effective multiple-charging systems in place that keep in mind a home’s panel capacity.

I hope, too, that we get a better sense of V2H setup and what’s required there for Rivian/Ford/Tesla…
 
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