For a 32 amp onboard charger, you only need a 40 amp breaker.Is it a 50 amp breaker with proper sized cable for distance? Is it the only thing on the circuit?
What is the max draw of your EVSE? The car will take 32 amps. That needs 40 amps of headroom so it should be 50 amp.
I believe Mateo1147 is referring to the hugely oversized breaker. In reality, if the onboard charger, or the J1772 handle were to short, the breaker would see way more than the 40 amps needed to trip it. I know the Bolt has a thermistor watching the charge port temperature, and the car is surely watching the onboard charger too. If either of those turned into a low wattage toaster, the car would likely shut the charge down, even if the breaker didn't trip. But Bolt2019 is correct, the stock EVSE, run on 240 volts, should have a 15 amp breaker.Why? The OEM EVSE internals were designed to accept 120-240VAC 50-60Hz to make it compatible with international markets. In the US, it has a 5-15P on it. Easily changed to a 15-50P, but you lose the plug's thermal protections doing so. I'd think that plugging an OEM EVSE into a 14-50R would give a much larger contact area, and thereby reduce the chances of a high-resistance heat-generating connection.
Because your LED lamp isn't as likely to burn down the house? I know, I'm reaching here.Why? The breaker is about protecting the wiring, not the plug in device. I have a 6W LED lamp sitting in front of me. It's on a 20 amp circuit. I would not reduce the circuit breaker to 1A because of the low power of the device plugged in. Why would an EVSE be any different than that?
An actual short in any device will trip the breaker. This is not an insignificant function of circuit breakers.Circuit Breakers are there to protect the wires in the walls.
It knows not what is happening with the current, as long as it's less than its rating.
Granted. Our garage outlet is wired for a 90 amp circuit, but I have a 40 amp breaker for our 32 amp onboard charger. Way safer than one wired for 50 amp service, and fused with a 50 amp breaker. Much better to have more wire than you "need", and a breaker closer to your load.It is more dangerous to be closer to your breaker's rating. for the wiring and the receptacle. I'd much rather have my toaster plugged into a 20 amp outlet than a 15 amp outlet. Maybe that's why you have to have 20 amp outlets in a kitchen nowadays.