I have a Nema 14-50 outlet installed with a 50V breaker. When I start charging, it is always at 32A, however, lately before reaching my end point, it will be reduced to 16A. If I reset the breaker or unplug and plug in the charger, it will start charging again at 32A. What could be causing this? Thanks.
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Charging Goes from 32A to 16A
- Thread starter wynnek
- Start date
It does sound like it's part of the onboard charger going out, but the OP's signature says it's a Model 3 SR, so that only has the 32A charger in it. So that would be 1 of the 2 modules failing, not 2 out of 3.
It would be really helpful if you could tell us on the charging screen if it says 16/16 or 16/32 when you see it reduced like that.
There's that funny display bug in the mobile app, where it shows you're using 17 out of 16 amps. But yes, that's very informative that there's a warning about heat at the outlet. That very likely is a loose wire connection in the back of the outlet then.
After the last drop to 16 amps and getting the error message, I reset the breaker and made sure there was very little slack in the cord. Previously I had a large amount hanging so I could step over it if necessary. The car charged at 32 amps without a problem until it reached the end. Could the cord have caused the problem?
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Its very unlikely. The car's telling you that the plug was too hot, so it dialed things back so your house didn't burn down.
That isn't a Leviton outlet, perchance?
There's a temperature sensor in the plug, so the problem is going to be around there. Either the installer didn't wire a solid connection to the outlet or the outlet isn't gripping the plug cleanly.
In either case, I'll give my usual recommendation of using a high quality outlet like Hubbell.
In either case, I'll give my usual recommendation of using a high quality outlet like Hubbell.
Well, maybe. Is the outlet a bit high up, where this slack cord was hanging with its own weight pulling down on the cord from the outlet? In other words: You know how there's the plug adapter, and that goes into the electronics box of the cord? It could have been effectively pulling that connection of the adapter to the box apart some. That's why they recommend to support the box and slack cord some, so it doesn't just hang. It might have made the sensor connection loose or something, and when you rearranged it to not be pulling, maybe that resolved some flaky signaling there.
brandon8387
Member
I have this issue because the temp outside combined with the heat on the UMC trips the temp sensor and it lowers the amps. I live in AZ so I have to charge in the evenings and overnight. In short; outside temp also matters
Mine was a failed onboard 16A section of my PCS. Had to be replaced under warranty. I took in the car and brought home a loaner and confirmed it was my vehicle that was the problem, not the charger.
I just noticed this today. I happened to look at the app this morning and was perplexed why the car hadn't finished charging yet at 7:15am (typically the notifications always show charging completes by 5:30-5:45am). The app also showed 239V and 16A/16A instead of the typical 32A/32A.
I checked the breaker just now and it looked fine. From what I can gather, this recently occurred two days ago but I haven't noticed any alerts in the car. The last time the charging cycle completed as normal was Monday. The past two evenings didn't report "charging completed" in the morning. I will submit a ticket to the SC to take a look at the onboard charger. It was 106 degrees yesterday but charging didn't begin until 12:35am last night and things should have been considerably cooler at that time.
I checked the breaker just now and it looked fine. From what I can gather, this recently occurred two days ago but I haven't noticed any alerts in the car. The last time the charging cycle completed as normal was Monday. The past two evenings didn't report "charging completed" in the morning. I will submit a ticket to the SC to take a look at the onboard charger. It was 106 degrees yesterday but charging didn't begin until 12:35am last night and things should have been considerably cooler at that time.
davewill
Active Member
Certainly a lot of tension on the cord could cause the plug to not be fully seated, which could cause heating. In your shoes, after the car had been charging for 10 or 20 minutes, I'd stop it, unplug the mobile connector and feel the blades of the plug. If they are too hot to handle, then something is wrong, and you (or someone qualified) should carefully inspect the outlet, the plug and the wiring inside the box for signs of overheating. The problem could be inadequately tight connections, wire insulation trapped in the outlet connection, or a cheap outlet.
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howardnj
Member
Is your wiring torqued properly at both the breaker and your outlet? Do you have the proper size wiring? If you have a cheap improper outlet, have a licensed electrician check
My Dad is an electrical engineer and helped install the NEMA 14-50. We used 6 gauge wire and a 50 Amp breaker. It was a pretty straight-forward install as the panel was directly on the other side of the wall. It has been working fine for the past three years for our Model S and now Model Y.
The S/Y are usually set at 32 Amps in the car but this morning I noticed the Y's charging screen was set to 48A, which is odd as no one has touch the charging settings. Anyways, I dialed it back to 32A and plugged it in for 20 minutes and it seemed to charge fine. The mobile charger felt warm during the brief 20-minute charging, not hot but definitely warm. I can't remember if it's supposed to be warm. I will hit it with a temperature gun later tonight to get a reading. Will also remove the junction box cover and peek at the wire connections.
There is no tension on the cord and we even have a hook to support the bottom of the mobile charger so it doesn’t hang freely from the outlet. I took the covers off and the wires all look fine, no evidence of melting, overheating, nor breaks/separation. Furthermore, the Y itself hasn’t thrown up any “charging reduced” errors.
My service appointment is on the 26th but Tesla is already planning to replace the mobile charger. I am hoping they will check the onboard charger as well.
Other items in the garage (ladder, roll of carpet, hood of second car) are all registering 95 degrees, but the mobile charger itself is at 110 F. Is that normal? The mobile charger is plugged into the wall but not actively charging. Anyone else with a temperature gun that can offer a comparison please?
My service appointment is on the 26th but Tesla is already planning to replace the mobile charger. I am hoping they will check the onboard charger as well.
Other items in the garage (ladder, roll of carpet, hood of second car) are all registering 95 degrees, but the mobile charger itself is at 110 F. Is that normal? The mobile charger is plugged into the wall but not actively charging. Anyone else with a temperature gun that can offer a comparison please?
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