In the RV world, 30 amp service means a 120V TT-30 outlet, and 50 amp service means a 240V 14-50 outlet.
It doesn't have to make sense, that's just how they do it
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Why does NEMA 6-20 (240v 20a) get 4x the charge of 5-20 (120v 20a)?
- Thread starter user212_nr
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In the RV world, 30 amp service means a 120V TT-30 outlet, and 50 amp service means a 240V 14-50 outlet.
It doesn't have to make sense, that's just how they do it
darth_vad3r
Well-Known Sith
Does the car think the voltage is flakey when it sees 120 instead of 240 and reduce the amperage to “safe” levels? Or is that a supported use case?
Oh hmm... they made a “Tesla” adapter, so hey reverse engineered whatever protocol there is from adapter to the brick and can tell the car 120 V @ 24 A ... interesting, I thought there’d maybe be some “authentic Tesla” chip authentication. Maybe they scavenge the chip and reprogram it?
Not sure how gen2 UMC does it. I think gen1 just had a resistor of specific value in the plug ends if I remember right.
The pricing is such that they could be buying a 14-30 adapter, cutting the plug off, wiring the TT-30 on, and over molding with rubber.
davewill
Active Member
The logic that decides whether the voltage stability is an issue is built into the car and wouldn't come into play unless the voltage fluctuated.
As I recall, he is cannibalizing Tesla adapters for the "smarts" and embedding it in his own plug. Anyway, the adapters aren't all that smart. They just signal the amperage of the adapter and whether the plug is over temperature. The mobile connector itself is happy to accept any of 120v/208v/240v regardless of the adapter. I think one person here even tested with 277v single phase (not that I recommend it), and I'm pretty sure a few people have run the NA Gen1 UMC on 230v single phase internationally.
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No, it looks at the voltage before the car starts drawing current. This is its baseline.
As the current ramps up, the IR drop will cause the voltage at the car to become lower.
this difference in voltage between 0 current and full current charging is what the car considers for testing if flakey.
The car has never cared about the difference between 120V or 240V on the two incoming voltage pins; it will just detect and use whichever it is. Back when Tesla had very few official adapters, we made all kinds of 120-->240 or 240-->120 homemade adapters, as long as you were matching current levels, and the cars never care.
Been over 6 years ago, so if my memory is correct, some of us very early S cars were software limited to 24a @120v, and the later 2013 S models could charge 40a @120. Since the brick on both Gen I UMC and Gen II MC don’t recognize v (the car does, which allows me to charge at 240v on a “standard” unadulterated 12ga. 5-20 terminated extension cord and a Tesla 5-15 or 5-20 OEM adapter without the need for a manual amperage adjustment), I am guessing my 3 can charge up to 40a @120v with a Gen I UMC. I am just too lazy now, don’t really care
, and have too many other ongoing projects to bother to determine if the max 120v charging is 24, 32, 40, or 48a on my M3.
, and have too many other ongoing projects to bother to determine if the max 120v charging is 24, 32, 40, or 48a on my M3.Been over 6 years ago, so if my memory is correct, some of us very early S cars were software limited to 24a @120v, and the later 2013 S models could charge 40a @120. Since the brick on both Gen I UMC and Gen II MC don’t recognize v (the car does, which allows me to charge at 240v on a “standard” unadulterated 12ga. 5-20 terminated extension cord and a Tesla 5-15 or 5-20 OEM adapter without the need for a manual amperage adjustment), I am guessing my 3 can charge up to 40a @120v with a Gen I UMC. I am just too lazy now, don’t really care
It should be able to charge as fast as you want on 120V. I’ve seen posts here of people who hired electricians to install a 14-50 but had the neutral and one of the hot wires installed backwards so they were charging 16 MPH at 32A/120V on the remaining correct phase for a while, until the problem was corrected.
There is a real thing there you are trying to remember, but your memory is failing you with the numbers. I remember being involved in that discussion on the other forum at Tesla's own site. It's kind of ancient history now and affected very few people.Been over 6 years ago, so if my memory is correct, some of us very early S cars were software limited to 24a @120v, and the later 2013 S models could charge 40a @120. Since the brick on both Gen I UMC and Gen II MC don’t recognize v (the car does, which allows me to charge at 240v on a “standard” unadulterated 12ga. 5-20 terminated extension cord and a Tesla 5-15 or 5-20 OEM adapter without the need for a manual amperage adjustment), I am guessing my 3 can charge up to 40a @120v with a Gen I UMC. I am just too lazy now, don’t really care
On the very early 2012 and 2013 Model S cars is what you are thinking of. Some programmer inside Tesla didn't think there were any 120V outlet types higher than a 5-20, so he though he would "solve" everyone's problem by putting a hard, unchangeable cap on all 120V charging at 16A. This was somehow hard-coded into the internal charger, and they never were able to fix it with any over-the-air firmware updates. But by about the beginning of 2014, someone had told Tesla about this mistake, and they got it fixed in the chargers they were installing into the newer build cars.
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