50amp motor coach hook-up

Greetings again: Next to the underground fed 200amp disconnect and meter socket I plan on installing a 50amp recepticle for motorhomes to use while visiting short stays. From the 200amp panel, I'm using 3 #6 wires - red, black and white and a seperate #6 wire from a separate ground rod driven below the 50amp recepticle box. The planned connections would be: red&black to the double 50 amp breaker, white to the neutral buss bar. At the recepticle box I would wire these 3 leads to the proper spots on the 4 connections of the recepticle - with the 4th connection being the separate ground wire to the ground side of the recepticle. Questions: Will it work and will the white connection only to the neutral buss bar at the 200amp panel be enough to trip the breaker - keep in mind, the ground buss and neutral buss ARE connected together at the service panel. Thanx