The 50a breaker appeared to not have tripped in the breaker box as it was still in the on position.

When a breaker trips, the switch doesn't flip over to the "off" position. When I trip one, I need to flip it to "off" then back "on" to reset it. So your breaker probably did trip.

So now you have to figure out why it tripped. Check the user's manual for the type of mobile connector you have. You mentioned UMC and amber lights. Model 3s are delivered with the CMC, which only mentions red and green lights in the manual.

https://www.tesla.com/sites/default...s/default/files/downloads/gen_2_mobile_connector_owners_manual_32_amp_en_US.pdf

 

You mentioned UMC and amber lights.

I'm guessing from the charge port.

 

Absent some malfunction, the car by itself cannot exceed the capacity of a 50A circuit.

1. There shouldn't be, but it's possible something else is being fed by this circuit.
2. If there is a malfunction, the mostly likely item is the breaker itself; second most likely would be some bizarre behavior of the car, which can indeed be full of surprises.
3. Your priority, however, is the very dangerous situation a breaker is designed for: a short in your wiring. It only takes one mouse - it happens. Not an easy thing to sort out for wiring buried in a wall - wait for another interruption, fire extinguisher and voltmeter at the ready?

 

Do this only if you know for sure you’re comfortable with it. Otherwise hire an electrician.

Turn off the breaker, pull the 14-50 outlet out of the wall, and look for unusual smells, melted or burned areas. If the outlet is damaged at all, or the Mobile Connector doesn’t plug in securely, swap it out for a new one.

If it looks and smells ok, make sure the wires are secure, and tighten them down with a cordless drill (heavy gauge wire is tough to get tightened down enough by hand), but don’t crack the plastic. If there is any excessive bare wire visible after they are tightened down, insulate with electric tape. Also, if it was installed originally so the Moble Connector plugs in upside down, flip it.

Occasionally the outlet might be installed in a too-small box, which is not ideal, but you can wrap the body of the outlet itself with a couple winds of electric tape to keep it from arcing when a lot of amps are drawn. And if the outlet is outside, that’s a good idea anyway, since debris or insects might move in and short it out.

That takes care of most things that could be wrong, excluding a wiring fault in the path to the outlet from the breaker, or a bad breaker, or a bad Mobile Connector. The rest you’ll probably need an electrician for.

 

First question. Are you using any 3rd party adapters? Or all OEM? Like a Tesla 14-50 adapter.

What is the breaker size and what is the max amps shown on the car when it is charging.

 

Darn it, I forgot the easiest and most obvious. Pull the 14-50 head off the Mobile Connector and then reconnect, making sure it snaps in flush with the Mobile Connector body.

 

99% of the time, a tripping, non GFCI, breaker is due to overload. Next most common is a bad connection at the breaker causing it to over heat. A poor connection elsewhere will certainly cause issues but won't cause a breaker to trip. Unless a total melt down and eventual short. Weak connections are LESS load. Breakers don't go bad that often. They do go of course, but not that often. And long EV loads that run at 80% can be hard on the entire connection, including the breaker mount and internal contacts.

An arc fault breaker is designed to trip on weak intermittent connections, because that is what is most likely to cause a fire.

I'd also be curious if the breaker that tripped was hot. If checked immediately it tripped.

Now thinking about it more. I bet the breaker didn't trip. A tripped breaker does normally move to the half position and usually, fairly obvious.

Something might have faulted or tripped on the other end and turning the breaker off and on, reset it.

Good Idea to reseat plug on UMC and reseat the wall.

Check if anything is HOT. Something might have over heated and tripped.

 

In the manual, it warns against unplugging the UMC while the car is actively charging. When a breaker trips, it is effectively doing that. Not that I've experienced any problems myself when I unplugged the UMC from the wall while the car was charging (I did it once by accident) but the warning in the manual suggests to me that weird things might happen if you do.

 

the manual suggests to me that weird things might happen if you do.

pretty much any consumer electronic thing, if it is a vacuum or an EV, warns not to unplug while the thing is running. the weird thing that could happen is you become the electricity's path of least resistance.

 

I was having a problem with intermittent trips of the 50A breaker (NEMA 14-50 and mobile connector). I had an electrician out to check everything over and install a new breaker. The problem seems to have been fixed at this point.