Level 2 charger overheating in garage

[matty0505]

Just ran for 1st time here in PHX. Charged 1 hour at 48amps then stopped and flashed red. Is the garage being over 100 degrees too hot or something else going on?

 

[rjpjnk]

How can the Wall Connector detect a lower voltage on one leg if there is no neutral? Does it use the ground conductor for this test? I guess it could.

 

[Tronguy]

How can the Wall Connector detect a lower voltage on one leg if there is no neutral? Does it use the ground conductor for this test? I guess it could.

Um. In the U.S., with residential split phase, the neutral and ground (as in, a stake in the ground, with a wire going into the breaker box) are bonded together in the breaker box. This isn't true for sub-panels, but the main panel has that.

So, in general, the two hots should be about the same with respect to safety ground. And it's been pretty much confirmed that either the Tesla Wall Connector, the Tesla Mobile Connector, or the car itself (or all three?) check for droops on a hot, whether it be L1 or L2.

 

[mongo]

Um. In the U.S., with residential split phase, the neutral and ground (as in, a stake in the ground, with a wire going into the breaker box) are bonded together in the breaker box. This isn't true for sub-panels, but the main panel has that.

So, in general, the two hots should be about the same with respect to safety ground. And it's been pretty much confirmed that either the Tesla Wall Connector, the Tesla Mobile Connector, or the car itself (or all three?) check for droops on a hot, whether it be L1 or L2.

Sure, phase to phase is monitored, and the phases should be the same voltage, but 120,100 measures the same 220V as 110,110. So the question was: does the Tesla wall connector monitor L1 to ground voltage to be able to detect leg specific issues.

It may, given the L2/N labeling and this error code.

Six (6) red blinks Overvoltage or poor grid quality detected, charging disabled Verify that the power supply is nominal 200-240 volts. If the issue persists, have an electrician remove the Wall Connector from the wirebox and confirm that voltage readings are as expected at the terminal block using a multimeter. Record the voltage readings for the following: L1 to L2/N, L1 to Ground, L2/N to Ground

 

[Tronguy]

Sure, phase to phase is monitored, and the phases should be the same voltage, but 120,100 measures the same 220V as 110,110. So the question was: does the Tesla wall connector monitor L1 to ground voltage to be able to detect leg specific issues.

It may, given the L2/N labeling and this error code.

I'm honestly not that much of an expert on this kind of thing. However.. In my life as a person with a Voltmeter, I've had occasion to stick said voltmeter into NEMA5-15 sockets and the like to verify What's In There. (Mostly when Making Really Sure the appropriate breaker was open, but verifying whether room light switches were working or not. And one notable case finding out why a neighbor's stereo speakers had a strong 60 Hz hum, even with the amplifiers unplugged .)

The answer is mostly what you'd expect: 120 VAC from Hot to neutral, roughly 120 VAC from hot to safety ground, and, interestingly, a volt or three from neutral to ground. I've always taken this last to be the voltage drop on the current-carrying neutral as compared to the non-current-carrying safety ground.

Where it definitely got Other was when I did the same at various and sundry work locations. No question: From Hot to Neutral it was always 120 VAC or a close facsimile. However, Neutral to Safety Ground was typically 15 VAC or so or higher than that and the Hot to Safety Ground was offset by the same amount.

Well, city power at work was provided by high tension wires into an area containing massive transformers and surrounded by a high fence, and I'm pretty sure that 440 3-phase (or maybe 600 3-phase?) was used to deliver power around to the various buildings.

But that 15 VAC (or bigger) difference implied that safety ground and neutral had only a passing acquaintance with each other. I'm sure it was all to code, but I guess code for Big Buildings is something very different than for residential split phase.