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I'm not sure what data logging has to do with your electrical wiring. All the car's logs can do is tell the engineers what type of fault or error occurred. It won't tell them what specific part of your electrical and power supply system may have triggered that error or fault. The car isn't psychic and doesn't know what's behind your walls. That's between you and your electrician. Obviously the car is encountering something in your electrical system that is causing a fault. You've gone through multiple UMCs, all of which exhibit the same behavior. The logical next step would be to have an electrician check your wiring for anomalies.
...or look at the charger in the car - I've seen at least 2 individuals say on this forum that a replacement of their master charger fixed this issue for them.
I'm confident now that engineering is involved they'll find the answer. Or at least have a data point so they can improve things.
I've only skimmed the thread, but I must admit I'm somewhat intrigued by the idea of finding a couple Model S owners to join me on a road-trip to qwk's place to try his outlet.
On the flip side...
@qwk - If you find yourself in the Seattle area, you're welcome to try my 14-50 outlet with your car. Also we could try various combinations of outlet/umc/car to try diagnosing over some tea.
On the flip side...
@qwk - If you find yourself in the Seattle area, you're welcome to try my 14-50 outlet with your car. Also we could try various combinations of outlet/umc/car to try diagnosing over some tea.
dhanson865
Well-Known Member
I wish everyone on this thread were as positive and useful as you are. Nice to see that post.
It's great that you don't have the issue, but it's clear to me that thousands of customers have this issue - including me. I used my Model S and UMC for 14 months and charged at 40A without any issue. Then after FW 5.8.4 the car refused to charge at 40A. It backs off to 30A. I've had multiple visits from the power company and electricians and Tesla Service center personnel and everyone says the 50A circuit is fine and line voltage is within acceptable levels. The tolerances in Tesla's firmware update are too aggressive. As a result, thousands of customers are no longer receiving the charging capability that they paid for (40A at home).
Basically if you don't have squeaky clean voltage coming to your panel with minimal fluctuations, you will likely have issues trying to charge at 40A. It's counterproductive when owners who don't have the problem scold those who do, as if it's their fault. Since the car requires electricity to be used as intended, I consider it an expensive appliance. Every appliance must be designed to work within the same tolerances that the power company deems to be acceptable. Tesla now requires tighter tolerances for Model S. This is bad for business, and it's getting out of hand.
Unlike a dishwasher, all Tesla needs is one horrible garage or house fire to pretty much screw over their entire plan for widespread EV adoption. They're obviously erring on the side of caution.
People need to get their wiring checked out and fixed because by definition that shouldn't be happening.
People need to get their wiring checked out and fixed because by definition that shouldn't be happening.
Rheazombi, DavidM said he has had numerous visits by his electric company and his electricians (plural), and that they indicated there is no problem with his line voltage and wiring. So, at least for DavidM, it does not appear there is anything with respect to his house wiring that needs to be fixed, as you suggest, but rather something with the car (software or hardware) that needs fixing.
Didn't realize I was scolding him but I was pointing out his asserting that Tesla seemed to have done this to him on purpose and the fact that he's gone through 6 UMCs (with a few of them melting at the adapter) is unusual and maybe there is more than just the software in his case. I certainly didn't blame him the individual. And yes, Tesla does need to figure out what is going on in situations like this. As I said in the post you quoted:
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Just my 2 cents... After upgrading to 6.1, my car charges at 71A rather than 80A. Think same issue? The voltage fluctuates from 202V to 199V. Very big fluctuation ;-)
While my car doesn't stop charging, I also get the current reduction to 30A occasionally. It started happening months after I got the car after one of the firmware updates (I forget which, but the 5.8.4 mentioned above sounds about right).
My voltage drop when the car starts charging is only about 4%. I've checked this both day and night... and the voltage drop varies very little. At my normal 3am charge start time I don't have significant other load in my house except for air conditioning running during the summer. Even when that kicks in it doesn't change the voltage drop much.
The other trigger point that has been discussed is line noise. There are very few loads in my house that possibly trigger during my overnight charging timeframe: HVAC, dishwasher (occasional), coffeepot, or refrigerators. Three of those have motor startup loads which can cause some line noise. The rest of my house loads are pretty static.
The car will happily charge for weeks at a time with those loads going on or off all the time without issue. Then occasionally, like this morning, it will be reduced. This is particularly annoying as I time the charge to end as I'm goging to leave in the morning, so I have a nice warm pack on these winter mornings. Starting some days with 25% less charge than intended on single-digit temp days can be a bit of a pain.
I've eliminated the dishwasher as the cause. The other loads always kick on and off while the car is charging, and don't cause issues 95% of the time. I suppose it COULD be line noise generated by the timing of 2 or 3 of those appliances kicking on at the same time... but I have my doubts.
What's odd is that I have LOTS of other noise inducing items in the house: a rack of servers, a dozen other computers/DVR's/STB's, a couple dozen lighting controllers/dimmers, etc... lots of things with switching power supplies or PWM circuits that generate EMF. None of those seem to bother it the slightest.
So if the issue is not line voltage, then whatever other threshold is triggering it seems a bit overly sensitive.
My voltage drop when the car starts charging is only about 4%. I've checked this both day and night... and the voltage drop varies very little. At my normal 3am charge start time I don't have significant other load in my house except for air conditioning running during the summer. Even when that kicks in it doesn't change the voltage drop much.
The other trigger point that has been discussed is line noise. There are very few loads in my house that possibly trigger during my overnight charging timeframe: HVAC, dishwasher (occasional), coffeepot, or refrigerators. Three of those have motor startup loads which can cause some line noise. The rest of my house loads are pretty static.
The car will happily charge for weeks at a time with those loads going on or off all the time without issue. Then occasionally, like this morning, it will be reduced. This is particularly annoying as I time the charge to end as I'm goging to leave in the morning, so I have a nice warm pack on these winter mornings. Starting some days with 25% less charge than intended on single-digit temp days can be a bit of a pain.
I've eliminated the dishwasher as the cause. The other loads always kick on and off while the car is charging, and don't cause issues 95% of the time. I suppose it COULD be line noise generated by the timing of 2 or 3 of those appliances kicking on at the same time... but I have my doubts.
What's odd is that I have LOTS of other noise inducing items in the house: a rack of servers, a dozen other computers/DVR's/STB's, a couple dozen lighting controllers/dimmers, etc... lots of things with switching power supplies or PWM circuits that generate EMF. None of those seem to bother it the slightest.
So if the issue is not line voltage, then whatever other threshold is triggering it seems a bit overly sensitive.
There were a few garage fires 18 months ago. Part of the blame was faulty wiring. Part of the blame was the UMC adapter. I'm not convinced that the firmware changes would have eliminated all possibility of fires. One bad electrician can bring a house down regardless of how Tesla changes the firmware. Actually, Tesla has tweaked the firmware's charging parameters multiple times since 5.8.4. I know this because right after 5.8.4, if voltage thresholds were exceeded, sometimes my car would back off to 30A, and sometimes it would stop charging completely. A subsequent firmware update fixed the problem of unintended charging termination.
Since you're VIN 43,000+ all of these changes happened before your car was delivered. Fourteen months is a long time to live with a washing machine whose "turbo wash" mode doesn't work (analogy), after it worked for the initial year.
No, it's exhibiting a problem you didn't know you had.
I'll say it again: the Tesla, power-wise, is *the* largest load that 95% of its owners will ever place on their electrical system in terms of kWh. You could even have a 48 kW stove, and it would still come nowhere NEAR the load and stress the Tesla puts on your electrical system. Similar to the newly-required AFCI breakers, the Tesla is looking for indications that an arc may be occurring.
The Tesla is seeing an electrical system signature of either high-resistance or arc-fault - which could be due to any number of things. In any case, it is a problem with your electrical system, as evidenced by the 95%+ of Tesla consumers who don't experience the problem on a regular basis. If it were truly a matter of bad thresholds set, we'd see a much higher case of it.
It is an indication of a fault somewhere in the electrical grid; whether bad transformer, bad appliance, bad wiring, or bad charger in the car itself.
I keep seeing people talk about "voltage tolerances" and such... please read the following (because it seems like it's being ignored): the tougher problems are NOT a matter of "voltage tolerance" and looking at the display on the car - as I said above. The power company will attach a voltmeter or a line analyzer meter at the service entrance and will look at the average voltage and frequency. They will not always see the instantaneous signatures that drive the downshift. They will tell you "250V, 60 Hz, everything's fine on my end" -- but if they can't measure the effects of reactive power from a bad appliance power supply or a bad starter capacitor, they won't always see it.
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The power companies don't always bring the right equipment. They'll typically bring a line analyzer which will watch the voltage and frequency and note any anomalies. These devices will not necessarily catch the arc-fault signature that's throwing the cars into downshifting.
If it doesn't happen over 80% of the time, it's not the voltage drop tolerance that is your issue.
There are two things to watch for: bad motor starter capacitors, which will generally dim incandescent bulbs significantly upon startup; and electronics with bad power supplies, where reactive power can make the voltage jump instantaneously.
Do you have a shared transformer with another home? Those loads could cause problems.
I understand the frustration - I really do... but what frustrates me is the attitude that it's Tesla's fault, rather than a responsibility to track down whatever source is causing the problem. The car is seeing an arc-fault signature. And those with that attitude want to point at Tesla and say they should turn the safety feature off so that arc faults aren't detected anymore.
"My anti-virus keeps saying I have malware. So I think Windows should just stop looking for malware."
It's not going to be a cumulative number of "noise inducing" items; it's going to be one of them. The example I cited earlier: a bad ballast in a fluorescent fixture introduced enough to trigger an AF signature.
A stove or electric heat unit rated at 200A would still never come close to the continuous charging load that the Tesla puts on your infrastructure.
It is *the* largest load that most homes will ever see.
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Arc faults can happen anywhere - loose transformer terminals, for example - and that would be PoCo responsibility. However, you're leading toward a conclusion of most people -- most people think of the branch circuit / appliance impacts. This is because of the recent requirement (NEC 2014, just being adopted now) that AFCI breakers are mandated for every 120V branch circuit. That is designed to protect against the most typical arc faults in homes (someone stretches a cord that tears apart the conductors, a plug is dislodged just enough that it pulls to the edge of an outlet contact, etc. An arc fault signature is a high voltage (simulating "open circuit") immediately dropping to a lower voltage as the arc is completed and current begins flowing (similar to an arc welder).
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http://en.wikipedia.org/wiki/Arc-fault_circuit_interrupter
AFCI will not protect against arc on the supply side however, only the branch circuit.
AFCI will not protect against arc on the supply side however, only the branch circuit.
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