My question is with the running watts being 3500 and the starting Watts being 4000 will an extension cord rated at 3750 Watts be enough ??
On the one hand I have read that Amps x Volts = Watts
So 12 Volts x 30 Amps =3600 Watts Max draw by the generator and Camper(30 AMP System) Right ?
Short answer is yes, it should be adequate. The 3750 watts means it can handle 30 amps at 125 volts. 3750W/30A = 125V. The receptacle on your generator is rated at 30A so that's as limiting as the cord. All of them have a bit of a fudge factor built in so a momentary surge to 4000W like starting an air conditioner isn't going to hurt anything, you're only going up to 32 amps for a moment. The longer the cord you have the more resistance you have so you have more voltage drop and loss of amperage to heat. The cable will get hotter on a longer cord than a shorter one if you're pulling a lot of amps through it. You're better off going with a shorter cord than a long one if you can get away with it. It'd really only be a factor if you're planning on running a lot of stuff all at once.
Most of the time a 30A circuit is going to use 10 ga. wire.
