If you have a generator prep package you should have a transfer switch. Take off the cover and look inside. It should have two 3 pole contactors in it. You should have one set of three contacts not being used. This is where your generator will connect too (Line1, Line2, and the Neutral) The ground also needs connected to the ground bus bar. On my new Columbus 295rl I just did this last week. I installed a 50A receptacle on the front of the trailer and run about 6' of cable to the transfer switch which is in the cargo bay. i keep the Honda EU7000is in the back of the truck. When you turn it on, it takes the transfer switch about 2 or 3 seconds to switch over and apply the generator power to the trailer. I didn't like the price of the generator prep package from the factory but now glad that I got it because it made it so easy to connect my generator without having to pull off the underbelly and run wire all of the way back to the breaker panel.