Pre wire for EV charger

[MacO512]

Whatever you decide, my advice is: Do not hardwire your charger. Having a 14-50 receptical gives you the flexibility to easily move your charger around in the garage AND you can easily remove the charger and take it with you on long trips. A lot of Airbnb's advertise now with 14-50 receptacles.

Regardless of what anyone says, a NEMA 14-50 receptacle for your charger is just as safe and just as efficient as being hard-wired in.

Disagree with this - 99% of the time I strongly prefer to hardwire.

If OP already has the expensive GFCI breaker and wiring that can't use 60 amps I can see the receptacle argument. This won't work with a Tesla Wall Connector though - you need an EVSE that is UL listed with a 14-50 plug from the manufacturer. Majority of them only charge at 32 amps such as the mobile chargers - although you can find 40 amp ones.

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[MacO512]

If you use a NEMA 14-50, I highly recommend using Hubbell 9450A. Leviton has cut corners on their outlet, and the Amazon cheap non-name stuff is garbage. Saving $35 and burning up the wiring or your house is a poor decision.

Yes agreed. Many electricians will even put in the junk $7 Leviton ones from Home Depot. Those are for ovens/stoves, maybe an RV that cycle on and off. Those are not designed for something that is sitting for half a day nonstop drawing huge current like our power hungry R1. Most likely those receptacle will melt at some point. Could be weeks, months, or years. Either way its a ticking time bomb. Search the internet for plenty of stories and pictures of it.

 

[MacO512]

For many people who charge at home overnight, being "stuck" at 40 amps is just fine. 48 amps is at best a 20% improvement over 40 amps (actually less due to heat losses), translating into 1 to 2 hours shorter charge time.

Its actually better than a 20% improvement due to power savings from the vehicle sleeping once charged. That exceeds increased heat loss. Heat loss can further be reduced by increasing wire size or a short wire run. A Nema 14-50 EVSE might have smaller wires than a hardwire unit so it actually doesn't have a heat loss advantage. But if its a hard wired unit set to 40 amps vs 48 amps yes there could be less heat.

40 amps is still very good and useable though. But why not get a hardwired solution when its cheaper to hardwire without expense GFCI breaker/commercial receptacle, less connection point of failure, and yes also the bonus of more power?

 

[Zoidz]

Its actually better than a 20% improvement due to power savings from the vehicle sleeping once charged. That exceeds increased heat loss.

40 amps is still very good and useable though. But why not get a hardwired solution when its cheaper to hardwire without expense GFCI breaker/commercial receptacle, less connection point of failure, and yes also the bonus of more power?

I'm not going to get into a debate about which is "better" - because that is dependent on the individual use case. As someone mentioned above, there are use cases where a plug in connection might be their best choice.

 

[BigSkies]

These are all great points and reflective of reality.

However, I want to point out to the OP that these are all fairly minor distinctions combined with personal preferences. There are about a dozen ways to do this (which have been listed through the thread) that are correct and will charge your car perfectly fine.

I personally have a single NEMA 14-50 outlet (50 amp) that charges both my Rivian and a Model Y using a Grizzl-e duo charger.

The 50 amp circuit has always been sufficient to keep two EV's fully charged for our families needs. I have never once needed to go to a backup DCFC because of limited charging speeds. Yes, a 60 amp circuit will charge the car faster. But the practical benefits are relatively small unless you have some extreme commute patterns.

You can choose to upgrade to a 60 amp circuit if you feel it's beneficial and worth the cost.

Every charger I'm aware of can be set to be wired to a lower-amp circuit. It's important to do correctly, but it isn't hard to do.

 

[MacO512]

I'm not going to get into a debate about which is "better" - because that is dependent on the individual use case. As someone mentioned above, there are use cases where a plug in connection might be their best choice.

I suspect most people that believe a 14-50 new install is better aren't fully aware of all the advantages and disadvantages of both options. There's a lot of people out there that think its cheaper to get a 14-50. Many of them are pricing a nonGFCI breaker (violates current electrical code) or a junk receptacle (huge fire risk).

 

[beatle]

5-6 years ago it used to make more sense to have a receptacle. That was before the GFCI breaker requirement, the need for a more expensive EVSE-rated receptacle, the cost of wiring went up, the cost of EVSEs went down, and the desire to have multiple EVSEs in a single home was more popular.

After my Leviton 14-50R melted, I reevaluated a replacement and it made a lot more sense to just install a hardwired EVSE.

 

[Mark_AZR1T]

Good info here. I’d recommend going with a direct wire connection only. Introducing a NEMA connector—especially one that will be pushing significant current for hours at a time—isn't ideal for long-term reliability.

Ask your builder if they can bypass the NEMA and wire directly instead.

While you're at it, I’d suggest getting a quote for pulling wire for a 60A circuit. I'm not sure where you are in the construction process, but I’m a strong believer in future-proofing. Running a 50A circuit in 2025 just doesn’t make much sense, especially with how fast EV charging and power demands are evolving.

 

[CampfireWisdom]

Great thread!

I’m gleaning lots of info here. I found out this weekend that my electrical panel is pre-wired for a dryer, but we have a gas dryer. We turned off the breaker with no affect to my house so we are good to go. In short, I was able to free up room on my panel for an EV charger. Happy day!!!

Based on the info here, I plan on…

1. Installing NEMA 14-50
2. Equipped with Hubbel 9450a
3. 6 ga. THHN wiring

Thanks for letting me soak up info from this thread!

Greg

 

[Zoidz]

While you're at it, I’d suggest getting a quote for pulling wire for a 60A circuit. I'm not sure where you are in the construction process, but I’m a strong believer in future-proofing. Running a 50A circuit in 2025 just doesn’t make much sense, especially with how fast EV charging and power demands are evolving.

That's exactly why I ran #2 and a new 100A subpanel.

 

[theonetruestripes]

Whatever you decide, my advice is: Do not hardwire your charger. Having a 14-50 receptical gives you the flexibility to easily move your charger around in the garage AND you can easily remove the charger and take it with you on long trips. A lot of Airbnb's advertise now with 14-50 receptacles.

Any arguments about 14-50 v hardwired aside, this isn’t nearly as important on a Rivian. The R1 still (in 2025) comes with a “travel charger” in the frunk. So if you buy a wall charger for your garage either because you like how it looks better, or because when hardwired it can charge faster, or because it has a rebate in your locale, or whatever you still have something to take to AirBnBs and/or RV campgrounds and whatnot.

I’m not saying not to go the 14-50 route (I did), I’m just saying “so you can take your wallbox on adventures” isn’t an important reason to do so as Rivian helpfully provides you with a travel charger that does 220V at 40A or thereabouts (is it 32A? I used it once to make sure it worked and packed it back up...)

 

[iQB]

In the case of this being a new build (assuming permanent residence), I'd recommend going with a hard wire install using #4 wiring on a 60A circuit. The install is exactly the same as the NEMA, except it requires larger wiring and breaker (#6 vs #4; 50A vs 60A).

When I made the switch from Tesla earlier this year, the first thing I noticed is how slow the R1T charges with the mobile charger (16-19 mph). I have the smallest battery (259) and if I take a road trip and drop below 10%, I can't get a full charge in 12 hours. That extra 6-9 miles of range per hour from the hard wired unit makes a significant difference when charging over extended periods of time.

 

[Zoidz]

In the case of this being a new build (assuming permanent residence), I'd recommend going with a hard wire install using #4 wiring on a 60A circuit. The install is exactly the same as the NEMA, except it requires larger wiring and breaker (#6 vs #4; 50A vs 60A).

When I made the switch from Tesla earlier this year, the first thing I noticed is how slow the R1T charges with the mobile charger (16-19 mph). I have the smallest battery (259) and if I take a road trip and drop below 10%, I can't get a full charge in 12 hours. That extra 6-9 miles of range per hour from the hard wired unit makes a significant difference when charging over extended periods of time.

Most current EVSEs are designed for #6 max wire size.

 

[iQB]

Most current EVSEs are designed for #6 max wire size.

Maybe I'm missing something, but I don't know of any EV hardwire install that'll support #6 wiring @ 48A. I think many of the manufacturers switched to 32A mobile connectors due to the 40A overheating long term on the NEMA 14-50s.

 

[Zoidz]

Maybe I'm missing something, but I don't know of any EV hardwire install that'll support #6 wiring @ 48A. I think many of the manufacturers switched to 32A mobile connectors due to the 40A overheating long term on the NEMA 14-50s.

From the Rivian EVSE Manual, pages 21 and 22:

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