ucmndd
Well-Known Member
You are correct about the EVSE function regarding "providing current" and I stand corrected. But you're going down a needless and far-fetched rabbit hole to describe a failure scenario that should be impossible if the microcontroller in the UMC adapter is designed with any sort of safety and common sense "fail closed" design principles in mind.It's built for 32A in extreme conditions like being outside in direct sunlight, yet here we're likely in a nice cool indoor space, given we're using a dryer plug.
Anything built for broad consumer use in these conditions easily has a 1.5X safety factor.
You really think stuff inside is completely fine at 32A but would melt at 48A? Nothing in the safety critical consumer space is built with that little margin.
Do you really think that if you pulled 55A on a 50A rated wire in your house that the expected outcome is fire?
You should take a look at Tesla's 80A Wall Connector and the cabling there and really question if the UMC looks like it would just melt into a puddle at 1/2 the current.
The UMC is literally just a relay between the outlet and the car. It doesn't regulate power or convert it at all. When plugged into a 50A outlet, what would prevent it from "providing" 48A?
It appears people have a fundamental misunderstanding of what an L2 EVSE is and what occurs inside. It's just a relay/contactor so that the connector on the end can't shock a human and doesn't have any voltage on it until safely plugged into a car. It also signals to the car the max current that can be utilized based on what circuit it's connected to. It's up to the car to not draw more current than commanded, and the EVSE doesn't have to protect for overcurrent.
What's likely happening has already been well documented in this thread. OP has a circuit problem that needs to be investigated and it's extremely unlikely that it's due to the UMC signaling more current availability than it should. It's not clear from the manual that the UMC does or doesn't have explicit overcurrent protection but it has at least 4 temperature sensors that would likely come into play if a device designed for 32 amps max is suddenly passing 48 for unknown reasons.
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