It could be a huge issue. "Damage" may not be visible to you. if the installer did not properly connect and tighten the wires feeding the wall connector they can eventually loosen, creating a higher than normal resistance in the circuit. This could potentially be a fire hazard, so I would certainly make sure you understand what the issue is and work to resolve it. Maybe it's just misconfigured, but if there is an electrical issue, it's best not to just live with it because you don't need the 48A.
And, to the OP: Just so we're clear: The screws that are torqued down to a specific torque that hold down the high voltage, high current wires in the TWC (or, for that matter,
in the car).. If they aren't torqued down properly, or lightly, one will get Incidental Contact between the wires and conductors where ever. Over time, with good old O2 (Oxygen) in the atmosphere, the oxide will build up until that incidental contact isn't so incidental any more.
Screwing things down properly gives one a gas-tight connection where the softer oxides get smushed out of the way and one gets true, metal-to-metal connection at a microscopic level (we're talking like,
welds here. Not quite a weld, but close.)
So an electrician who's busy rushing through the job, had half-tightened something down, had gone back and tightened stuff back up before finishing,
but missed one of those screws may have very well put you in the position you're in.
It's known that if the voltage, open-circuit (i.e., the Tesla isn't drawing current, but can see the presence of voltage) to the condition where there's a significant voltage drop (i.e., semi-open connection) will result in the car drawing less current, which is a "save-the-day" scenario that the software guys put in. Given that you're getting 30A, which is neither fish nor fowl as regards losing one of the rectifiers, there's a half-assed guess that this may very well be a loose connection.
And it doesn't have to be in the Wall Connector, either. A loose connection in the breaker box (a faulty-from-the-manufacturer breaker, a screw in there not tightened down properly, or a clip on the breaker that didn't clip properly, etc.) will Do The Deed as well.. albeit, more likely to result in flashy lights on the TWC if anything like that did happen.
Yeah, it's possible that the car's current setting got turned down to 30A for some reason: But you said that the car says, "48A" at your location, so I don't think so on that subject.
Now Hear This: This Is Not A Drill. Do Not Pass Go. Stuff like what I'm describing above is how, if the signs line up wrong, people get house fires. At the moment, the Save-The-Day function in the car TWC seems to be in operation. That's nice: But, belt and suspenders. If one is the kind of person who has to wear a belt and suspenders to keep one's pants from hitting the ground, going around with
one of those may be acceptable for a short time, and is better than not having the live backup. But this is a Bet Your Life situation, and I'm not kidding. GET THIS FIXED, ASAP.
FWIW: That logo up there is not a joke. Before retiring, I routinely got bent, broken, and burnt (as in, "holes in it") gear from the field and rigged things so
that, whatever that was, didn't happen again. I'm not an electrician, but I do play one when it comes to telecom failures. Don't screw around with this.
