Electrical contractor for our condo complex warns that using portable chargers such as Wunderbox plugged into 14-50 outlet may cause "nuisance tripping". Reason is that Ground Fault Circuit Interrupter ("GFI") circuit breaker must be using in wiring the outlet. He suggests using a permanently installed charger that is hard-wired to avoid this problem. Obviously would rather use the Wunderbox and Lucid cable to avoid buying another charger. I'm not sure if Wunderbox has its own built in GFI but believe having two of these in series may be part of problem. Does anyone have any experience as to whether problem real? How to avoid if using plug-in Wunderbox? Many thanks