Slight elaboration... Much like the "14-50" delivering 40A, the dryer receptacles (older "10-30" and newer "14-30") deliver 24A.
Not to put too fine a point on it, but they are still 40 and 30 amp receptacles capable of delivering that amount of power. Most jurisdictions' electrical codes have definitions for "continuous loads" (EVs fall in to this category), and circuits supplying these types of devices can only be loaded to 80% of their rated capacity.
To put an even finer point on it, Tesla's adapter will limit it to 24A on a 30A receptacle so that's kind of irrelevant. No?
Right. What I had in the back of my mind when I posted was that many people in many threads talk about home-made "cheater cords" and adapters. If someone made up a cord with a NEMA 14-30 plug on one end and a NEMA 14-50 socket on the other (to plug into dryer outlets on the road), then plugged their UMC's 14-50 into this adapter cord, it might be important to understand that the 30 amp outlet they're plugged in to needs to be de-rated to 24 amps due to the "continuous load" nature of the EV, and the car should be dialed down from 40 amps to 24 amps (not 30 amps). The Model S UMC notwithstanding, they are 50 and 30 amp receptacles (I mistakenly said "40" in my previous post).
I am working with a municipality to improve the city's EV charging infrastructure, and I wanted to give them a primer on the different EV charging options. The table in this thread is great, but I would like it to be a bit more comprehensive. First, it doesn't list NEMA 5-20 (small thing); second, it does not list specific J1772 chargers, which would give a sense of the range of options. In my experience, public J1772 chargers range from ~10 mi/hr to 55+ mi/hr (i.e., 4kW to 18kW), with most tending in the 14-22 mi/hr range. If you are traveling to a particular destination and want to travel back, the difference between 14 mi/hr (filling 208 miles of battery in 15 hours) and 22 mi/hr (filling 208 miles in 9.5 hours) is quite significant. The former means "overnight and a whole morning", while the latter means "day trip". Is the table being actively maintained? Alternatively or in addition, is there a wiki online with this information, so we can share and keep it updated?
Can anyone recommend an electrician in the SF Bay Area to install the HPWC for a Model S or point me to an existing thread
AMZ Electric; 925-216-8894. They did my NEMA 14-50 install and took care of the entire permit process. I was super happy with them.
To anyone coming across this thread, the adapters mentioned are available from Tesla's Model S accessories web page, including the $450 CHAdeMO: Tesla Accessories and Charging Adapters CHAdeMO Adapter NEMA 5-15, NEMA 5-20, NEMA 14-50, NEMA 10-30 @ $45 each.
Has anyone experienced the lack of conversation between the Model S and the J1772 charging system? I left my charge limit set at 70 % ('16 Model S 90D) and returned to find the battery charged to 90-95%. I asked the valet parking attendant if he'd changed the setting and he replied "NO". Wondering if I'll try leaving the car on that type of charger again. Lectrik.
A J1772 only can signal the car about the current it's able to deliver. It has no ability to set the charge limit of the car. Accidental setting via app? Forgot you had changed the limit? Another app/webservice somewhere triggered a scheduled event you forgot about? (The latter has happened to me).
Find what, or who, inadvertently set the charge level higher and then correct that. No charger (including a supercharger) should override the car's set limit. On the outside chance the car's system is malfunctioning and it's not honoring the set limit, take it in for service.
There's no documentation that the J1772 system will recognize or override the Tesla charge limit. You get what you pay for I guess.
The J1772 system tells the car the maximum current it is allowed to draw. Everything else - when, how fast and how much to charge - is down to the car itself. There is no possible mechanism for a J1772 chargepoint to 'force' a car to accept charge that it doesn't want. If the car charged to a higher level than you expected, then the car decided to do that - either due to a defect in the car's software, or because you (or someone else without your knowledge) set the controls to a different level.
@ChadS how can I download your amazing chart on charging specs? I'm a Tesla newbie and would love to have a copy of it.