So I may of made an mistake. For the last 3+ years I've been happily using the mobile connector to charge my car. It has worked well and I typically pull 40A at 237V. The car is equipped with the standard single charger. This fully charges the battery during the off-peak evening rates.
Every once in a while I go for a road trip to my sisters house. This depletes my SOC to less then 8% so I really can't do much when I get there other than to plug into a relatively slow 30A outlet. Recently I decided it would be great to install a connector at her house so I could visit more often and get a quicker charge that would allow me do some errands after a short time charging.
My first inclination was to install a NEMA 14-50 and charge at 40A as I do at home. The outdoor rated box cost me $29 plus a 50A fuse, wires etc. However, given that the wall connectors have dropped in price I thought it would be worth it to be able to pull 48A and reduce my wait time by an additional 20%. I was told 48A was the limitation for a single charger by the parts department representative. So I bought a 60 fuse, increased the wire size to #6 AWG and paid the $550+tax for the wall connector... I planned to return the NEMA 14-50 box.
I spend all morning yesterday installing said equipment. Since my sister has a surface mount main breaker panel, a couple of free breaker slots, and the panel just happens to be right next to the driveway, it wasn’t that hard to a drop conduit directly from the panel to the Tesla wall connector junction box. The Tesla 24' cord was more than long enough. In any case, I plugged it in … just to find I was only drawing 40A!!!
I called the Tesla information line and was told that the reason I couldn’t get the full draw was her voltage is less than 240V (The car indicated 230V or so). To get 48A I’d need to be at 240V. This don’t make sense to me as a lower voltage would imply a higher amperage for an equivalent power draw.
Does any one know what the limitation is? Is the onboard charger limited by current or power? If voltage is the limitation, shouldn’t I get 230 * 48 = 11.04kW? If the charger is limited by power shouldn’t I get 10,000 / 230 = 43.5A? I double checked my wall connector settings and confirmed that the rotary setting is to ‘9’ which allows 48A (the #1 DIP setting is down to indicate 240V or less). Heck with AWG#6 I believe I ought to be able to pull 60A per code (THHN 75A wire derated etc.) but I was being conservative.
The bottom line is that I don’t seem to be doing any better at all with a wall charger than using my mobile connector. I’m wondering if that is a problem with the car/charger or the wall connector. If either is a fundamental limitation then I’m thinking I’ll return it and replace with the much less expensive 14-50.
Every once in a while I go for a road trip to my sisters house. This depletes my SOC to less then 8% so I really can't do much when I get there other than to plug into a relatively slow 30A outlet. Recently I decided it would be great to install a connector at her house so I could visit more often and get a quicker charge that would allow me do some errands after a short time charging.
My first inclination was to install a NEMA 14-50 and charge at 40A as I do at home. The outdoor rated box cost me $29 plus a 50A fuse, wires etc. However, given that the wall connectors have dropped in price I thought it would be worth it to be able to pull 48A and reduce my wait time by an additional 20%. I was told 48A was the limitation for a single charger by the parts department representative. So I bought a 60 fuse, increased the wire size to #6 AWG and paid the $550+tax for the wall connector... I planned to return the NEMA 14-50 box.
I spend all morning yesterday installing said equipment. Since my sister has a surface mount main breaker panel, a couple of free breaker slots, and the panel just happens to be right next to the driveway, it wasn’t that hard to a drop conduit directly from the panel to the Tesla wall connector junction box. The Tesla 24' cord was more than long enough. In any case, I plugged it in … just to find I was only drawing 40A!!!
I called the Tesla information line and was told that the reason I couldn’t get the full draw was her voltage is less than 240V (The car indicated 230V or so). To get 48A I’d need to be at 240V. This don’t make sense to me as a lower voltage would imply a higher amperage for an equivalent power draw.
Does any one know what the limitation is? Is the onboard charger limited by current or power? If voltage is the limitation, shouldn’t I get 230 * 48 = 11.04kW? If the charger is limited by power shouldn’t I get 10,000 / 230 = 43.5A? I double checked my wall connector settings and confirmed that the rotary setting is to ‘9’ which allows 48A (the #1 DIP setting is down to indicate 240V or less). Heck with AWG#6 I believe I ought to be able to pull 60A per code (THHN 75A wire derated etc.) but I was being conservative.
The bottom line is that I don’t seem to be doing any better at all with a wall charger than using my mobile connector. I’m wondering if that is a problem with the car/charger or the wall connector. If either is a fundamental limitation then I’m thinking I’ll return it and replace with the much less expensive 14-50.
