4 AWG size for a 50 amp wire. This is the best size wire for 50 amp Rv service. Whether you have a 30 amp, 40 amp or a 50 amp breaker, wire size is essential. Before you take on any type of wiring job, be sure to know the exact size wire you need.

What size wire do I need to run my camper?

10-gauge wire is usually used for short 30 amp runs. If you plan on going over 150 feet, 8-gauge wire or thicker will be needed.