Building a new home, charging advice

timesinks

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If the main panel isn't in the garage, I'd feed a beefy subpanel (maybe 150A so you can have the EVSEs but also garage circuits, etc.). Then I'd get 1" conduit in the walls to a 4-square for each bay. I'd bring dedicated circuits of 6AWG wire to both boxes. If I didn't have a hardwire charger, I'd put a receptacle in the box (50A breaker) -- otherwise, it's just a splice box for a hardwire install (breaker sized per the manufacturer's instructions).

The 1" conduit makes it an easy job to upsize the wire or pull a neutral down the line without opening up the walls.

I don't know if driveway parking is a thing where you live, but when we installed EVSEs on posts on either side of ours, boring 21 feet across was a huge PITA. If that's something that you might want, bringing 1" conduit from the house panel to a post on one side of the driveway then more 1" conduit from that post to one on the other side of the driveway would be cheap and easy (before the driveway is poured) and would unlock outdoor charging options too (or could be repurposed for RV pedestals or who knows). So think about your outdoor/landscape infrastructure too.

 

ajdelange

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I'm responding to these comments under the assumption that OP is concerned with code compliance. Assuming that the builder is too he won't let you put a 14-50R behind a 60A breaker because it is a code violation.

Also, the EVSE I plan on getting is not limited to 32a. I'd suspect many aren't and the 32a issue is widely discussed among people having older chargers and or Tesla which did limit to 32A.
In keeping with the above; It isn't a question of the car. It is a question of the receptacle. It is a code violation to plug a 40A EVSE into a 14-50R receptacle if that receeptacle be installed on a 40 A circuit.

" flexible amperage settings up to 50 amps (16/24/32/40/48/50 Amp) "
Charpoint charger on Amazon
If I read the description correctly this is intended to be installed either with a plug or hardwired. It is adjustable but if it is plug connected it cannot be adjusted by the user. This particular EVSE requires setting the maximum draw in the app. This, of course, makes the setting accessible by the user and, techincally, therefore not code compliant.
 
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Redline

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Yeah, everything will be done to code and by a professional obviously. Just wanted to figure out what might make the most sense, especially with building from scratch.
 

RBR1S

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I'm responding to these comments under the assumption that OP is concerned with code compliance. Assuming that the builder is too he won't let you put a 14-50R behind a 60A breaker because it is a code violation.

In keeping with the above; It isn't a question of the car. It is a question of the receptacle. It is a code violation to plug a 40A EVSE into a 14-50R receptacle if that receeptacle be installed on a 40 A circuit.

If I read the description correctly this is intended to be installed either with a plug or hardwired. It is adjustable but if it is plug connected it cannot be adjusted by the user. This particular EVSE requires setting the maximum draw in the app. This, of course, makes the setting accessible by the user and, techincally, therefore not code compliant.
Help me understand your statements (I'm not challenging them). But you're saying effectively, it's against code to have anything plugged in that would draw 100% of the circuit - in your example 40A EVSE on a 40A circuit. Similar with the 50A device I linked plugged into a 50A socket, again 100%.
 

mkg3

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It seems that the discussion is all surrounding around the 14-50 plug but there are few other key items for your new home.

1) whatever plug/wall charger you decide to do, have a charging ability per stall (i.e., 2 for 2 car,, and 3 for 3 car garage and so on). There are chargers that can charge two vehicles at the same time but I rather have the redundancy and individual charger for each stall.

2) home integration device (inverter+isolation switch from grid) of some sort that allows you to power your house using your EV battery power. Let your EV be the backup battery pack in an event of a blackout.

3) I have no idea what the electricity rate or monthly cost for MN area but solar panels/roof can really help keep the EV operating cost down so consider that as a part of the new build too.

4) I know it snows and snows a lot in MN but consider having electrical outlets in various perimeter locations in your yard. Running a cable from the house outlet or landscape light really isn't sufficient.

5) I know this is completely off the subject but I am audio nut so think about provisioning/prewiring or even installing ceiling speakers for Dolby Atmos (say 7.2.4 arrangement) surround sound system for the home theater. The Atmos speakers provide overhead sounds and two in the front and two in the back gives you fore-aft-left-right sounds. Think of an aircraft flying from rear left to front right, as an example. Or thunder and lightning sounds. And don't forget about the rest of the speaker wiring and HDMI cables in the wall.

Good luck!
 


sub

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Code requires that a 14-50R receptacle be wired to a 50A or 40A circuit meaning, respectively, a 50A or 40A breaker and the proper sized wire for the breaker choice.
It is true that you can't install 60 amp breaker and a 14-50 outlet, but you can use wire that is rated for 60+ amps with a 50 amp breaker/outlet. That way if there's ever a desire to hardwire a higher capacity EVSE, all you have to do is replace the breaker and attach the EVSE.

Also for a two-car garage, I would wire up 4 to 5 of those 14-50 outlets. One in each corner of the garage, and if you're using two single doors another one more between the two doors.

The reason for all those extra outlets is because there is no standard for charge port location. Rivian's charge port is front left. If you only put an outlet near the front left corner and then your next EV has charge port in rear right, it will be very awkward to plug in.
 
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jjswan33

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You might want to consider if you will eventually want a bi-directional charger. Obviously the gen1 R1S isn't going to support this but if I were wiring a system from scratch I would want this functionality for home backup.
 

sub

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Help me understand your statements (I'm not challenging them). But you're saying effectively, it's against code to have anything plugged in that would draw 100% of the circuit - in your example 40A EVSE on a 40A circuit. Similar with the 50A device I linked plugged into a 50A socket, again 100%.
If the item is classified as a continuous load, It can only use 80% of the circuit's rating.

EV is classified as continuous load. So the max charge rate is circuit rating times 0.8.
 

ajdelange

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Help me understand your statements (I'm not challenging them). But you're saying effectively, it's against code to have anything plugged in that would draw 100% of the circuit - in your example 40A EVSE on a 40A circuit. Similar with the 50A device I linked plugged into a 50A socket, again 100%.
It turns on whether the thing being plugged in is an intermittent load or a continuous one the latter being any load which is on for 3 hours or more. Code defines EVSE to be continuous loads. Circuits supporting continuous loads must be derated to 80% of the circuit capacity. This the maximum EVSE load on a 60 A circuit is 48A, the maximum on a 50A curcuit is 40A etc.
 

Tomgriff

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Maybe somebody already said this and you probably already thought about it, but make sure your EVSE can reach where you are going to park. Since you are doing new construction I would also go with wiring to support 80 amp in case you are going to get a vehicle with vehicle to load (Ford Lightning max is 80 amp although I think it can still work with lower amp circuit but will have to be derated). Although much smaller batteries I charge a Tesla MS 70D and Chevy Bolt with a single Wallbox EVSE at 32 amps and have never had a problem keeping enough range in both cars.
 


Bigeasy70075

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I built 3 years ago. I have 2 garages. Had a 400 amp main service with 100amp circuit run to each garage. I have down sized to 50 amp circuit and 14-50 outlet for my Tesla. If possible would highly suggest the 100amp line (future proofing). Changing the breaker and receptacle are much easier and cheaper than running a new line later.
 

RBR1S

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This the maximum EVSE load on a 60 A circuit is 48A, the maximum on a 50A curcuit is 40A etc.
So the ESVE I linked would be against code regardless of plug or hardwired, since it says 50A and that would be 83% on a 60A breaker.
 

Dark-Fx

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So the ESVE I linked would be against code regardless of plug or hardwired, since it says 50A and that would be 83% on a 60A breaker.
Chargepoint Flex needs to be on a 70 or 80A breaker to be able to use it at 50A, it even states so in the installation manual. It can be installed on a 60A breaker and limited to 48A. But all of the above require it being hard wired. The wiring to the charger needs to be rated for whatever the circuit breaker is sized for.

If you're installing a 50A outlet, you can't put larger than a 50A breaker leading to it, which limits you to a 40A rate of charge. 60A NEMA outlets exist, but it's not a good idea to change out the whip for that because none of them are UL tested.

An OpenEVSE can technically be wired with the 60A whip on a 60A outlet with a 60A breaker and rated wiring, because it's a device you "build" yourself. But it still depends on whether or not your local code will allow it, some of them have limitations on outlets at a maximum of 50A.
 

ajdelange

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It is true that you can't install 60 amp breaker and a 14-50 outlet, but you can use wire that is rated for 60+ amps with a 50 amp breaker/outlet. That way if there's ever a desire to hardwire a higher capacity EVSE, all you have to do is replace the breaker and attach the EVSE.
I don't see any problem with that.

Also for a two-car garage, I would wire up 4 to 5 of those 14-50 outlets. One in each corner of the garage, and if you're using two single doors another one more between the two doors.
I just did a 3 car garage and started out with that attitude but quickly changed it when I started drawing up instructions for the electrician. Not only would it have cost a bundle but those 50 an 60A breakers take a lot of panel space. I wound up with 2 HPWC, one Pulsar and ane 14-50. The positions are designed to accommodate the X in the Leftmost slot, the CT in the center and the Rivian in the right all parked front end in.
 

ajdelange

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So the ESVE I linked would be against code regardless of plug or hardwired, since it says 50A and that would be 83% on a 60A breaker.
That's one reason. If you install it for plugin on a 50A circuit and commission it for a 50A circuit that objection goes away but you are still in violation becuse YOU, the user, can reprogram it without using any tools. This is a technicality of course, Lots of people have this, and similar, EVSE.
 

 
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