My Lectron "charger" has a 14-50 plug only and is fixed at telling the vehicle to charge at up to 40A.
The
level 1 Lectron Tesla charger that has a NEMA 5-15 plug only is advertised as a 15A unit.
110 x 15 = 1.65 kW
One of the reviewers said that they appreciate the 15A capability over other chargers which are 12A (which would be correct for a NEMA 5-15 plug since 80% of 15A is 12A).
Their
level 1 J1772 charger claims 16A capability, yet still has a NEMA 5-15 plug only.
It appears to me that Lectron is banking on NEMA 5-15 receptacles being connected to a 20A breaker using 12 AWG wire which does meet code, but isn't universal - especially in older homes.
OK: Your Lectron... let's call it a "Connector", since, in this case, the actual charger is in the car.. has a NEMA14-50 plug. The NEMA14-50 socket that one plugs that into should have both the wire (good for 50A+) and breaker (50A); and, so, you should get 80% of 50A = 40A, so you're good.
Except for a snivvey of which you should be aware. As it happens, in the 240 V world, there are 10A sockets; 20A sockets; 30A sockets, and 50A sockets. But, as it happens, no 40A sockets.
And then, of course, there are things like clothes driers and stoves that are 40A.
The problem, so called, is that Electricians Hate Spending Money On Expensive Copper. So, somehow, there has appeared in the NEC an Exception: One can use a NEMA14-50 socket on a
40A Circuit With 40A wire and a 40A breaker. I don't actually know, but I presume that any such usage should be marked and labeled so that, later, if some person with a welder (or Tesla) shows up, they don't draw 40A on a 40A circuit, which is a good way to try and start a house fire.
You got a 50A breaker there, right? (You probably do, but just giving you a thing to check. Safety.)
And that is hypothesized why the Tesla Mobile Connector only does 32A with the NEMA14-50 adapter. The idea is that Tesla has no idea if one has a
real 50A circuit out there, in which case 40A is fine, or one of these NEC-exception 40A circuits, in which case 32A (80% of 40A) is the only safe way to go. So the idea was that they opted for safety.
OK. So, here's the Lectron pulling 16A on a NEMA5-15 socket. That Is Just Wrong. Just like everything else about that NEC 80% rule, it's not just the wire, it's the hardware. A NEMA5-20 socket
is rated for 20A usage and can handle 16A indefinitely. A NEMA5-15 socket is very, definitely,
not rated for 16A or 15A continuous. Now, the way that a NEMA5-20 socket is put together, one can plug either a NEMA5-20 plug (that's the one with one of the blades at right angles)
or a regular NEMA5-15 plug, either will go in.
Just took a walk out to my garage; 2004 construction, so relatively new. The GFI outlet is NEMA5-15 and the breaker box has a 15A breaker on it.
And this is why, when people talk about certain Chinese companies, the words, "Sketchy" comes to mind. Also: The words, "Lawsuit proof", because the principals are in China and don't give a Rat's #@%.
If the setup is with you, with a NEMA5-15, 12AWG, and a 20A breaker.. You're still trying to risk you, and your family's, lives.
Basic: Power dissipation in conductors goes as the square of the current. So, a NEMA5-15 at an NEC max continuous load of 12A is dissipating some power at the contacts, both where the wire's connected to the body of the thing and the sliding contacts on the blades. That power creates heat energy that has to be dissipated. That gets dissipated through physical heat conduction and radiation. The result is that there's a temperature rise on the plastic and metal parts in there that, when the environment is at its maximum temperature, is
below the temperature where the plastic and insulation starts degrading. And the manufacturer has data and test results to prove it.
Does the manufacturer want to beef up the heat dissipation and temperature so this 15A socket can handle more than that 12A continuous load? Heck no. That's Wasting Money And Reducing Profits and Giving The Competition A Leg Up.
So, say that you run this thing at 15A. How much of an increase in power and temperature are you going to get? (15/12)^2 = 1.56. The power dissipation goes up by 1.56 and so does the temperature. How much do you want to bet that over the years, this is going to make that socket crack and potentially start a house fire? Especially if there's a 20A breaker out there
that'll let even more current flow.
As they say: You Bet Your Life. And That Of Your Family. Every time it gets hot out there, this thing is going to degrade.
Further: Say you have an actual 15A breaker out there, not a 20A breaker. Breakers have thermal elements, generally. When Too Much Current Flows, the thermal element expands and trips the breaker.
Remember that bit about 80% of 15A max continuous load? The breaker manufacturers know that part, too. And they arrange things so if one goes from 0 to 12A to 0 to 12A and so on, the
flexing of the thermal element doesn't cause the breaker to die. 0 to 15A.. The breaker's
nominal popping point is 15A. No, you don't want the breaker to fail closed Come The Day when an actual short occurs.
That Lectron connector should be blocked at import and the principals fined or jailed for endangering the public. No, I'm not kidding.
