Hi, I am going to wire a 30 amp 4 prong inlet box to my panel. Im am back-feeding it to a 30 amp 220 breaker and have installed the Square D interlock device that will not let me turn on the breaker without turning off the main. My panel is 3 wire. Inside the inlet box there is the x,y,w,g terminals. The G terminal has a green wire running from the terminal to the frame of the inlet box. I was going to run wire from the x and y terminal to the breaker and wire from the w terminal to the neutral bar. Do I need to run a ground wire from the G terminal as well and go to the neutral bar? I have no ground bar. If the inlet box is attached to the panel by metal conduit will this serve the same purpose. Thanks for any help.