2551 Phoenix w/30 amp - I carry a 25 foot 10 gauge extension cord incase I'm at site that needs the extra length to reach the post. Recently an electrician at an RV park told me I should be using a 25 foot 8 gauge extension cord because of heat and line loss. I've been checking around and haven't found any available for 30 amp. It has me wondering if because the RV places don't even carry the 8 gauge maybe what I was told is not right. Does anyone have any expertise as to what is correct or what is the safest wire gauge to be using for an extension cord for 30 amp service?
If I was using a 25' extension to the coaches original 25', then I would want a #8 on the extension. That is using copper wire, on 120 volt single phase. If per chance you are using an aluminum extension cable, then you should use #6. I would never use aluminum as there are too many problems with heat and dis-similar metals. Bob