I would appreciate some help with a wiring project. I have a new 200 amp single phase rural service for which I'm wiring service to an RV. The project involves wiring a 50 amp 4 wire 220 amp plug into the 200 amp main panel mounted to my meter pole. The plug will be housed in a rain proof box. The box will be mounted to the pole just below the 200 amp main panel.
I bought some AWG NO. FOUR tray cable. It contains 3 insulated conductors with bare ground (4 conductors). I have never used tray cable before. Upon peeling back the outer insulation I discovered to my surprise that the individual conductors are not color coded. Rather, they are all black and are labeled ONE, TWO, and THREE in white letters along the length of the individual insulated conductors.
My question is: Is there some accepted NEC "standard" designation for the two hots and the white? Or do I just arbitrarily assign ONE as red, TWO as black, and THREE as white (or whatever?) Call me a chicken but I find it unnerving that the conductors are not color coded.