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Gen 2 NEMA 14-50 backed down to 8A


Sep 8, 2020
Virginia, USA
A mobile service tech replaced this for me today, and I'm back up and charging full speed, but I'm curious as to what happened.

I had been charging using this setup at home, Gen2 MC with 14-50 at 32A, for about 6 months. When I went on vacation, I took the mobile connector with me. There was a 14-50 receptacle where I was staying, but at first, the MC did not light up. I found that the breaker was turned off, so I turned that one. Then, I was getting 5 red blinks on the T, and the current was limited to 8A. This happened even when the not plugged into the car. I assumed there was an issue with the receptacle.

Once I was back home, however, the problem continued. I dug up some info on the MC signaling, and it looked consistent with no adapter information being reported to the MC. It was reporting "Wall plug adapter error", not anything regarding overheating. The 5-15 adapter was recognized correctly, and it was charging at 12A, and the MC does work correctly now with the new 14-50 adapter. It also seems that overheating will usually limit charging to 16A with a 14-50.

The adapter was fully inserted into the MC, so I don't think there was a connection issue. The tech said he had never seen this issue before. Do you guys take any precautions before plugging into an unknown receptacle? From what I read, the detection circuit on the Gen 2 is more complex than just a sense resistor. I wonder if that active communications circuit failed somehow, and if so, the timing of using a different receptacle seems like it would be a big coincidence.

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