I've had two electricians come to scope out work on my townhome installation. The first claimed I only had 20amps available but the other claimed I had 50. My heating and stove are gas-powered. How do I know which to trust? If I use the UMC with a NEMA 14-50, will the car automatically use what's available without tripping the circuit breaker? Any risk of damaging the car, charger, or breaker? thx!