New house, need guidance for at-home charging

[Runt8]

Based on our call, I think I’ll add a 60a circuit on the main panel and wire it straight to a 14-50 outlet. If and when my wife gets a Y and we both need to charge at the same time, I will remove the outlet and daisy chain two HPWCs. Electrician thought a sub panel was a needless expense.

I'd definitely go this way - wire it for 60a, but only install a 50a breaker with the 14-50. Then adding one or two wall connectors in the future is trivial.

 

[NickFie]

O. Other: I would do a 60A 240V circuit on the main > Garage Sub with 60A breaker > 2x HPWC daisy chained. Both cars plugged in, they'll share 24A each (more than enough for daily commute). 48A will allow for max charge rate for 1 vehicle at a time.

It will be rare that both cars need 48A and plugged in at the same time. Unless you road trip with both driving... which I can see as both persons want to drive their Tesla haha.

100A cable vs 60A cable = mucho dinero

Consider extra cost of 100 Amp cable over 60 Amp cable as percent of total job cost.

I’ve rarely looked back at technical decisions and wished I had specified or designed less capacity.

Also, experience shows that it’s best to get future-ready the FIRST time work is done. Follow-on work is less expensive, faster and less disruptive.

In that light, I would...

Have electrician run cable for both HPWCs to the sub-panel while it’s easy.

Terminate your wife’s prospective HPWC cable in a junction box at right location and install a blank cover. Leave sufficient slack to easily connect to HPWC.

If you set up HPWC to share a circuit (best option in my opinion) junction blocks in subpanel would connect breaker and HPWC hots.

Have electrician run shielded, twisted pair cable for HPWC communication between the two points, with adequate slack.

Easy to later change charge technology. Disconnect second HPWC power cable from junction blocks in subpanel and connect to second breaker, for example. Put the 240 Volt outlet of your choice in the junction block. Or attach some other home charge point to the slack in the junction box.

Another subpanel benefit- have electrician install a lock on the breaker and you should meet code for adjacent cut-off on high power charger.

Finally, a solid, adaptable and powerful charging setup will make your home appealing to more future buyers.

Good luck!

 

[Urbancowboy]

Quick update: I swapped out the GFCI receptacle, and charging on 120v now works! Honestly that’s enough for most of my usage. In AZ I had a 55 mile round trip commute and was able to replenish that with 14-15 hours of charge on 120v. Now that I’m in Nashville my commute is 14 miles round trip so I’m actually fine without 240v for a while... But I still want to get it done for weekends and running the kids all over town for sports.

I like the idea of future proofing now while most of the cost is being incurred. I’ll get an estimate for both 60a and 100a and see what the difference is.

Thanks again all.

 

[brkaus]

We have 2 Teslas. Share a single HPWC on a 50a breaker. No issues based on our commute.
Typically share every 3 days.

 

[5_+JqckQttqck]

Well in case the next car isn't a Tesla. Having one 14-50 and a spare blank box at XAmps is also a good option