I have installed a Connecticut Electric transfer switch for my generator (7500 watt) to my breaker panel and now I want to run wire from the switch 60 feet inside the house and hook up to an outlet (30 amp) that will be attached to an exterier wall of the house. I have purchase a rain tight outlet box, the only thing I need to do is run the wire into the back of it from the basement.

The question is, I purchased 10/3 NM-B with ground wire, the wire has a white, black, red, and un-cased ground. Would this be the correct wire to use? I had the impression that I needed 10/4 wire, with the ground wire cased,(green) but the Home Depot person stated that since this is an interior installation, that the 10/3 is what I need. Is the 10/3 wire correct? The transfer swich has a red, black, white and green wire to hook to.

Thanks for any help.