I'd get the work your electrician did independently checked. I had a LICENSED electrician that was on the Tesla recommended list install my Tesla wall charger before I had my solar panels and two powerwalls installed. The wall charger was to be set for 80 amps as they ran a new 100 amp line from my breaker box. When Tesla installed the solar panels and powerwalls I found my wall charger did not work correctly. The Tesla electrician determined the "licensed" electrician ran a 3 wire not a 4 wire so the grounds were not correct (there are 2 separate grounds required). The wall charger was smart enough to sense this. He also found the internal switches were incorrectly set, as other suspect yours might be. (my electrician did read the manual so not sure why a recommended electrician would be confused) The electrical code required a breaker disconnect within 5 feet if you have more than 50 amps. The "licensed" electrician installed a 100 amp breaker disconnect but put a 80 amp in the breaker box...go figure. The Tesla electrician confirmed they installed the correct gauge wires for the 100 amps (I'm an engineer so I like to have margin in my designs). The Tesla electrician set the internal switches to the correct setting and I had the "licensed" electrician come back and pull the missing ground wire, connect the missing ground as required, and install the correct breakers in my breaker box. I also called the owner and requested a 50% refund as their "licensed" electrician screwed up and that they were recommended by Tesla for wall charger installations. I got my 50% refund and everything has been working fine. Tesla really came through on this as it would have taken me awhile to go through the electrical wire diagrams and figure out the "licensed" electricians screw-ups.
This does not make a lot of sense.
The Wall Connector only requires three wires. Two hot conductors and one ground. Perhaps in your install they installed a subpanel and then fed the Wall Connector off of that? In that case, the sub panel probably should have a four wire feed (two hots, a neutral, and a ground).
I am not sure about your jurisdiction, but the 2017 NEC has no such requirement about a disconnect within five feet. The current code does have a requirement for a locking disconnect that is "readily accessible" if your circuit is *over* 60 amps - not 50. The general consensus is that the locking disconnect can be a breaker handle tie off and it does not have to be in line of sight.
Installing an 80 amp breaker for the Wall Connector would be fine if the wall connector was set to allow a max amp draw of 64 amps (the table in the install instructions lists both 64 and 80 for that dip switch setting - 80 is the circuit rating, but per NEC continuous loads like an EV can only use 80% of that). So it sounds like they installed 100a capable wire and should have installed a 100a breaker and then set the Wall Connector to allow 80a max charge rate (100a circuit).
I do agree that a huge percentage of electrical installs are done wrong! Just because they are professionals does NOT mean they do things right all the time. I see a ton of sketchy stuff.
Op here. We set the switches and now are charging at 32 amps. Charging much faster now, yeah!
I did what Tesla directions told me; 40 amp circuit for the sr+. As a electric car newbie I hear about battery stress And degradation, I didn't want to take any chances and followed the rule book.
Great! What dip switch setting did you end up going with? And did you figure out what kind of wire (what gauge and type) was used?
Note that there would be absolutely zero issue going with larger wire or a 50a breaker (if you have the right size wire). The car would still charge at the same speed and be completely code compliant and safe.
Generally around here we don't like recommending installing new NEMA 14-50 or 6-50 receptacles on 40a circuits since it is fine today with the UMC Gen 2, but if someone else later plugs in a different EVSE that can provide 40a continuous then they will likely get nuisance trips and it could draw too much current if you only had 8awg wire (in theory the breaker protects from this).
Glad you got it resolved. No worries on the charge current, 40A is plenty reasonable for both you and the battery. You could technically install a 10000A imaginary wall connector and the SR would still only charge up to 40A. The wall connector isn’t a charger, just a fancy extension cord with safety stuff inside. The charger is in the car, so it controls the show. But there’s no advantage to running a wall connector above 40A for your car anyways.
Please note: The SR, SR+, and MR only have 32a onboard charger. That coupled with the UMC Gen 2 having a limit of 32a (regardless of what model vehicle it is attached to) means your limit is 32a. It is NOT 40a. Yes, 40a is the required circuit size to do the full 32a max rate, but that is due to the 125% / 80% derating rule.
