Do you mean that you need 5o-foot extension in addition to your RV's shore power cable? If so, get a heavy duty extension from an RV supply place. The fridge, operating on electric mode, does not draw a lot of power. Buy a simple plug in line voltage monitor and keep an eye on voltage under load. Operating appliances below 100 volts may damage the appliance. I was able to run the roof AC unit on an extension cord except when local line voltage dropped on hot days when homes were running their AC units. I finally had a dedicated RV outlet installed on the outside of the garage during a remodel. Make sure rig is nearly level when running fridge for extended times, much off level running will shorten the life of the cooling unit.