30A RV cord vs 50A RV cord vs household extension cord: Household cords are dangerous for RV hookups; choose 30A or 50A based on your RV's inlet.

Household extension cords aren’t built for sustained high loads and can melt or catch fire. For RVs, use a 30-amp (TT-30, 10-gauge) cord for smaller RVs or a 50-amp (14-50, 6-gauge) cord for larger ones. Match the cord to your RV’s inlet, not the park pedestal, and use an adapter if needed. Don’t cheap out on gauge — a thin 50-amp cord heats up fast under load.