Just wanted to chime in here. Mine was the first Leaf to suffer a diode failure of the charger in April 2011. If you look at the circuit diagram there is no way that the GE Wattstation can over power the diode. It is protected by circuits / components which limit current and voltage. About the only thing that could get in there would be a high voltage negative spike on the ground from a lightning strike (cause of the #2 failure in Tennessee). They tried to blame my TIG welder but the car was 30 miles away when it failed.
The only other possibility would be a static discharge not shunted because the ground pin on the J1772 connector is recessed and not connecting first.
I suppose if the contactor is putting out a sizable negative spike when disconnecting, that could have an effect if the circuits are not sufficiently isolated. But if that were true it would not have passed the UL tests.
Just my .02
Nissan replaced the charger under warranty.
I'm wondering if I am understanding this correctly.
First, the diode failed when the car was "30 miles away," which I am interpreting as being at a different EVSE than the GE Wattstation. I don't understand how it can be determined if the diode failed at the beginning of the charge at that EVSE or at the end of the charge from the GE unit.
But if a different EVSE caused the diode to fail, that would indicate that it is more likely a problem with Nissan than GE.
Also, as smkettner asked previously, it would be interesting to hear if bowthom has continued to use the Wattstation without problems.