Will do thanks! gives me a good reason to break out my torque wrenches which I haven't had to do in a while lol
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Can changing amperage while charging simply be heat related?
- Thread starter robbyville
- Start date
If it triple blinks red before continuing the green light sequence, this is high temperature detection from the unit itself. How old and what part number is the connector? My 2020 connector had the same issue, I want to say the part number ended in “F”, and there was an issue with the optical temperature sensors in the faceplate of the connector. It had since been revised to a “G” part number and Tesla had a new one to me in a couple days.
There’s a few older threads on here about it.
No electrician needed, its just the face plate that needs changing if this is the issue. They were able to remote diagnose it and saw the issue right away, this was also during temps around 35C, into the 40’s with humidity…
Jared
There’s a few older threads on here about it.
No electrician needed, its just the face plate that needs changing if this is the issue. They were able to remote diagnose it and saw the issue right away, this was also during temps around 35C, into the 40’s with humidity…
Jared
Hmm...so the vehicle is somehow thermally limited and cannot charge 48 amps at 240v...that's not even 12kW...it is nothing compared to DC charging or how much power the motors generate with regen braking (up to 70 kW).
I'm not convinced this is a thermal issue on the car side.
Is your regen also behaving oddly?
My money is you have an issue with the wiring on the wall connector end.
I'm not convinced this is a thermal issue on the car side.
Is your regen also behaving oddly?
My money is you have an issue with the wiring on the wall connector end.
Shelburne
Member
I wrote earlier about a similar problem I'm having with slower charging. I have a 240 volt line with a Nema 14-50 plug. I use my mobile charger to connect all that to my M3. Over the past two years I've noticed that the rate of charge, while normally at 29 miles of range per hour, frequently drops down to 14 miles of range per hour. The amperage drops from 32 amps to 16 amps. This seems to happen less in the winter and more in the summer. We get a few 90 degree days here in the summer but mainly we are in the 80's. Yesterday, the electrician who installed the wiring and the 240 volt plug checked it all out. He did see that one of the wires was a bit loose where it connects to the 240 volt plug so he tightened it. I started charging the car and about 60-90 minutes later I checked the app to see how fast it was charging. Once again, the charging rate had dropped to 14 miles of range per hour at 16 amps. The temperature was in the mid-70's and the car was in the shade so I don't think it's heat related. The mobile charger and it's plug and cable didn't feel hot, but could the problem be with the mobile charger and how can I check that out?
ucmndd
Well-Known Member
Charging fluctuations in 16 amp multiples can also indicate a problem with your car’s power conversion system (onboard charger). Before doing anything else I’d charge your car somewhere else on another L2 charger to rule out the vehicle itself. If you see the same behavior elsewhere, it’s the car. If not, it’s your home charging setup.
Shelburne
Member
Charging fluctuations in 16 amp multiples can also indicate a problem with your car’s power conversion system (onboard charger). Before doing anything else I’d charge your car somewhere else on another L2 charger to rule out the vehicle itself. If you see the same behavior elsewhere, it’s the car. If not, it’s your home charging setup.
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Thanks, but I've already done that. It charges just fine at a Supercharger and also at a Chargepoint charger. I think my next move is to have a different electrician look at my charging set up - a second opinion as it were
LikeQuoteReply
Thanks, but I've already done that. It charges just fine at a Supercharger and also at a Chargepoint charger. I think my next move is to have a different electrician look at my charging set up - a second opinion as it were
ucmndd
Well-Known Member
Supercharging is not a valid test. The ChargePoint may be if it was level 2 and not a DC fast charger.
Next thing to look at would be the voltage the car reports during charging.
What does the car report immediately after you start charging, while the current is ramping up?
What does the car report about 30 minutes in, while still charging at 32 amps?
What does the car report later in the session, after it’s dropped to 16 amps?
If the car detects a significant drop in line voltage, it responds by reducing the current by 50%.
Regeneration seems fine. Charged at 32 yesterday and stayed that way for the entire time. Still need to check the wiring and lugs
Yeah, so let's be clear about all this.
First: you all probably know this, but power dissipation in anything with resistance goes as P = I*I*R, where I = current, R = Resistance, and P is the power, in watts. Got a hank of wire? It's got resistance. Got a wire clamped between two pieces of metal with a bolt? Copper->OtherMetal will have resistance at the joints, typically more than a straight piece of wire, so of course power is dissipated there.
Then, there's this concept: Thermal resistance. It kind of looks like Ohm's law, but it isn't. Those of us who muck with this kind of thing use the Greek letter, "Theta". I'm not going to spell it out; let's use H. Then,
Tdevice = H * P + Tambient
So, the temperature rise above ambient is the Power being dissipated in something times the thermal resistance. In the above, H can be roughly fixed. One will get one value of H, say, for something sitting in still air (with convection cooling, say) and a much smaller value when one is pointing a fan at it.
Next note: H can add. Suppose that, to get from the joint where the power is being dissipated, one has to go from, say, the joint to the air in the Wall Connector; then, from the Wall Connector case to the outside world. So there'll be a Hj-case and an Hcase-air, and the total H would be the sum of the two.
Final note on this: H can, kind of, divide. Say one has a big honking copper wire. Get one end of it hot and it's going to thermally conduct. (The characteristic is thermal conductivity and one can look it up.) Of course, now with that wire warm, since it's not in the ambient air but surrounded by insulation, conduit, dry wall, and all that, well, the equations get complicated. In any case, for multiple parallel paths H1, H2, H3 to ambient from some point, we get
Htotal = 1/(1/H1 + 1/H2 + 1/H3 ...). Just like EE201 and resistors in parallel.
So, going back to a Wall Connector: Well, there's not much air circulation in there, so whatever the heck H is for the joints in that box to the ambient, it's probably roughly constant.
Now, what is in that box is a temperature sensor. So, roughly, we got Tdevice, or something which is pretty closely related to that being reported to the car/Wall Connector electronics. Here's the problem: Above some temperature in that box or around that joint, the insulation and/or materials in that box are going to deteriorate. This isn't rocket science, everything goes bad if it gets hot enough, including rocket engines. (I've heard the term, "engine-rich exhaust" on some notable.. well, the engine didn't work so well events.) So, reducing the current seems like a right good idea in such a case.
And that makes really good sense. Remember where I said that P = I*I*R? That's a squared term. If 48A is too much, dropping it to 24A is dropping the current by half and the power dissipation by 1/4. And that means that Tdevice - Tambient also goes down by a factor of four, thus saving the day.
So, at this point nothing should be a surprise. Got a loose joint? That'll have higher resistance. Crank up the torque and get it back to spec: If the resistance goes down by half, so does the temperature rise.
But, there's more! On another thread in this forum there was a fellow with a NEMA14-50 (or something like that) and a Mobile Connector. The charging current would drop off. You can probably see where this going: The Tesla Mobile Connector does, indeed, have a thermal sensor in the adapter plug. The socket was all fastened to its wires just fine but it was warm in that garage, so the expected, reduced current to Save The Day kicked in. I suppose that getting a better wall socket from a higher-quality manufacturer might have improved matters somewhat, but this guy's solution was decidedly low tech and effective: He aimed a small fan at the wall socket. Remember what I said about H being variable in the presence of moving air? Worked like a champ.
A hundred linear feet per minute of moving room temperature air can do wonders, vs. the 10 linear feet per minute that one can get with convection. Give it a try? After making sure things are torqued down properly: Safety first!
First: you all probably know this, but power dissipation in anything with resistance goes as P = I*I*R, where I = current, R = Resistance, and P is the power, in watts. Got a hank of wire? It's got resistance. Got a wire clamped between two pieces of metal with a bolt? Copper->OtherMetal will have resistance at the joints, typically more than a straight piece of wire, so of course power is dissipated there.
Then, there's this concept: Thermal resistance. It kind of looks like Ohm's law, but it isn't. Those of us who muck with this kind of thing use the Greek letter, "Theta". I'm not going to spell it out; let's use H. Then,
Tdevice = H * P + Tambient
So, the temperature rise above ambient is the Power being dissipated in something times the thermal resistance. In the above, H can be roughly fixed. One will get one value of H, say, for something sitting in still air (with convection cooling, say) and a much smaller value when one is pointing a fan at it.
Next note: H can add. Suppose that, to get from the joint where the power is being dissipated, one has to go from, say, the joint to the air in the Wall Connector; then, from the Wall Connector case to the outside world. So there'll be a Hj-case and an Hcase-air, and the total H would be the sum of the two.
Final note on this: H can, kind of, divide. Say one has a big honking copper wire. Get one end of it hot and it's going to thermally conduct. (The characteristic is thermal conductivity and one can look it up.) Of course, now with that wire warm, since it's not in the ambient air but surrounded by insulation, conduit, dry wall, and all that, well, the equations get complicated. In any case, for multiple parallel paths H1, H2, H3 to ambient from some point, we get
Htotal = 1/(1/H1 + 1/H2 + 1/H3 ...). Just like EE201 and resistors in parallel.
So, going back to a Wall Connector: Well, there's not much air circulation in there, so whatever the heck H is for the joints in that box to the ambient, it's probably roughly constant.
Now, what is in that box is a temperature sensor. So, roughly, we got Tdevice, or something which is pretty closely related to that being reported to the car/Wall Connector electronics. Here's the problem: Above some temperature in that box or around that joint, the insulation and/or materials in that box are going to deteriorate. This isn't rocket science, everything goes bad if it gets hot enough, including rocket engines. (I've heard the term, "engine-rich exhaust" on some notable.. well, the engine didn't work so well events.) So, reducing the current seems like a right good idea in such a case.
And that makes really good sense. Remember where I said that P = I*I*R? That's a squared term. If 48A is too much, dropping it to 24A is dropping the current by half and the power dissipation by 1/4. And that means that Tdevice - Tambient also goes down by a factor of four, thus saving the day.
So, at this point nothing should be a surprise. Got a loose joint? That'll have higher resistance. Crank up the torque and get it back to spec: If the resistance goes down by half, so does the temperature rise.
But, there's more! On another thread in this forum there was a fellow with a NEMA14-50 (or something like that) and a Mobile Connector. The charging current would drop off. You can probably see where this going: The Tesla Mobile Connector does, indeed, have a thermal sensor in the adapter plug. The socket was all fastened to its wires just fine but it was warm in that garage, so the expected, reduced current to Save The Day kicked in. I suppose that getting a better wall socket from a higher-quality manufacturer might have improved matters somewhat, but this guy's solution was decidedly low tech and effective: He aimed a small fan at the wall socket. Remember what I said about H being variable in the presence of moving air? Worked like a champ.
A hundred linear feet per minute of moving room temperature air can do wonders, vs. the 10 linear feet per minute that one can get with convection. Give it a try? After making sure things are torqued down properly: Safety first!
Exscite
Member
Same here: My Wall Charger is too worm, the red light blinks once and the charge speed is reduced from 32A to 16A, thus doubling the charge time at home.
My question- DOES ANYONE HERE HAVE A CREATIVE SOLUTION FOR COOLING OFF THE WALL CHARGER?
My setting:
My new Model Y is one month old, but this 4.5 year old wall charger was installed inside my garage for my old (now sold) M3. I live in SoCal and it is a hot summer. It is connected to the 240v, 32A line. I think that the problem of overheating occurs mainly in the summer- so I am looking for a cool, cooling solution.
My question- DOES ANYONE HERE HAVE A CREATIVE SOLUTION FOR COOLING OFF THE WALL CHARGER?
My setting:
My new Model Y is one month old, but this 4.5 year old wall charger was installed inside my garage for my old (now sold) M3. I live in SoCal and it is a hot summer. It is connected to the 240v, 32A line. I think that the problem of overheating occurs mainly in the summer- so I am looking for a cool, cooling solution.
Three thoughts, in no particular order:
- I have a Gen II TWC and two Teslas, a 2018 M3 and a 2021 MY, which take turns using it from time to time. 48A we got. I'll tell you, it gets hot in NJ. The TWC is in the garage, near the doors. Never had a problem.
- Going along with the above: Speaking as a EE who's had to break down burned and busted equipment for a living, Figure Out Why, then Change Things So It Never Happens Again: Loose wires aren't exactly new. Every time when there's heat (expansion) and coolth (contraction), well, things shift. Electrical connections are supposed to resist issues associated with that kind of movement, but the phrase, "Supposed to" raises hackles on my neck. Given the number of years, that's another (possible) flag. Pop the breaker on the breaker panel, get the front cover of both the breaker panel and the TWC removed, and torque all the appropriate screws down a bit, being Very Careful in that Live Breaker Box. (You might want to think about popping the Mains.) Can't hurt, you might find something. Loose connections will very definitely cause Lots Of Heat.
- Further, to my knowledge, a sudden drop in voltage as the current raises up is to a Tesla as waving a red flag at a bull. The Tesla software guys figured this to be an indication of a loose or broken connection and this also causes the current to drop. Now, this might easily be a loose screw/joint as described above. But it could also indicate a bad breaker. I've read data sheets on fuses and breakers and one of the more interesting statements from the people who build these things is, "A breaker/fuse is a thermal element. Like all thermal elements, like light bulbs, they have a finite life. Here's some numbers.." and they go on from there. So, a dead breaker, while not #1 on my list of possible "on nos!", is not at number 57. They're $20-$35 or so at Home Depot.
By the by: On another thread, a punter mentioned that a so-called electrician put aluminum wires into a TWC that's only rated for copper. Look for corrosion while you're at it.
Last thing: Back when I was a newbie trainee in the USN, my old Chief Petty Officer stated, "90% of your problems are going to be with the wires." He was right. Visual inspection and a little tugging to and fro helps, a lot.
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