Tesla wall charger issues

[tatoweb]

I always charge my car at 35 amps even though the app lets me top it at 48 amps.

Recently, I raised it to 48 amps and after a while, it dropped to 25 amps by itself and showed some lights on the charger (I did not take a picture). I also noticed the cable gets really hot when charging.

I have a 60 amp breaker.

Today, I raised it again to 48 amps and it didn't dropped, but the cable was very hot.

What could be causing the drop and cable temperature?.

Thanks.

 

[LoudMusic]

The cable will get warm from use. Electricity flowing through metal has that effect

How much it warms up is based on a few factors, the biggest is resistance in the wire. Bigger wires allow the electricity to move more freely and thus less resistance and less heat. This is the chart I usually reference. It says for 60 amps you need 6 or better yet 4 gauge wire, depending on length of run. It should be written on the side of the cable. You might have to disassemble things to find it. Be sure to turn off any brakers for areas you're working in.

http://assets.bluesea.com/files/resources/newsletter/images/DC_wire_selection_chartlg.jpg

The wall connector (charger) has temperature sensors in several places. If it detects that any of them are too warm it will reduce the amps attempting to prevent overheating and fire. I don't know what those temperature values need to be, but I'm sure it's somewhere on the internet, probably this forum. You can get a cheap infrared temperature gun to find the surface temperature of your equipment.

Is any portion of your charging cable in direct sun during charging?
Is the ambient air temperature particularly warm?
Is there any air circulation in the area?

Somewhat related is voltage sag/dip. When amp consumption increases it's common for voltage to go down. If voltage goes down too much the wall connector (charger) will reduce amps in order to recover voltage numbers. For good troubleshooting it would be good to know what voltages your wall connector (charger) and car are seeing during non-charging and each of the amp values that you reported above.

 

[tatoweb]

This is what my invoice says. It is inside the garage so no direct sunlight. Yes, air temperature is warm inside. Air, just as any regular 2 car garage.

 

[DerbyDave]

You didn't state the age of your car or the connector. In 2020, Tesla had a problem with the connectors overheating, and could take a look at mine over the Internet and sent me a new one. They have a 4 year guarantee.

Don't email Tesla about this or contact service yet. The Connector Support Team never responded to my emails, but they eventually wrote to me to contact them by phone:

"Call our Home Charging Support team at 877-961-7652 and select the option for wall connector. The team is available M-F 8 AM to 5 PM PST."

This number is probably the only number at Tesla where you can actually talk to a person. Hopefully it is still staffed with a human. Within a day, they had determined the problem and had started shipping me a new one.

 

[DerbyDave]

Also, you can get the temperature inside the connector and other Vitals if you know or can get the IP address assigned to the connector on your network. Put this in your Browser: http://192.168.x.xxx/api/1/vitals replacing the x's with your numbers from the real IP address. It will then show you all this at the time you connect to the wall connector, including on mine a current alert, and temperatures. The alert I have is because the connector cannot charge because I have it charge early in the AM when electric rates are low.
{"contactor_closed":false,"vehicle_connected":true,"session_s":13904,"grid_v":244.8,"grid_hz":59.988,"vehicle_current_a":0.0,"currentA_a":0.0,"currentB_a":0.0,"currentC_a":0.0,"currentN_a":0.0,"voltageA_v":2.1,"voltageB_v":2.1,"voltageC_v":2.1,"relay_coil_v":11.9,"pcba_temp_c":29.9,"handle_temp_c":28.7,"mcu_temp_c":36.1,"uptime_s":274236,"input_thermopile_uv":-136,"prox_v":1.5,"pilot_high_v":8.6,"pilot_low_v":-11.4,"session_energy_wh":1.100,"config_status":5,"evse_state":4,"current_alerts":[],"evse_not_ready_reasons":[1]}

 

[LoudMusic]

View attachment 1056018

This is what my invoice says. It is inside the garage so no direct sunlight. Yes, air temperature is warm inside. Air, just as any regular 2 car garage.

6awg seems appropriate.

In addition to what @DerbyDave said, it's also possible the installer didn't get all the screws tightened down appropriately. That seems to have been an issue with others' installations, and can cause resistance and heating. Could be that something is slowly burning out.

 

[DerbyDave]

Actually, 4awg is the spec for 48A at 240V, 6awg is OK for a stove or other intermittent connection not in spec for continuous 48A. It is in spec for 40A continuous. I also have the wrong 6awg wire connecting mine, and it works at 48A, but I usually charge slowly at 32A.

The brains on this board convinced me of this spec. I was furious, not at them but at my electrician.

 

[Cosmacelf]

Actually, 4awg is the spec for 48A at 240V, 6awg is OK for a stove or other intermittent connection not in spec for continuous 48A. It is in spec for 40A continuous. I also have the wrong 6awg wire connecting mine, and it works at 48A, but I usually charge slowly at 32A.

The brains on this board convinced me of this spec. I was furious, not at them but at my electrician.

6 gauge when using THHN in conduit is the spec for 48A charging. 4 gauge only when using NM-B cable.

@tatoweb install is correct.

 

[1989pooch]

new connector needed? I had tesla replace mine under warranty when it started acting funky, they were pretty quick about it. give that support # a ring, worth a shot.