AC and generators.
The new fifth-wheel has a 15K btu AC on it. What size generator do I need to run that thing when we are boondocking?
Forum Discussion
jamesroadking wrote:
Power measured in Watts is the Question. The Formula is P over I E.
Power Over I Current measured in Amps (30 amps) times E Volts (120 volts)
30 amps X 120 volts = is 3600 watts, to run your RV. Now to run just your A/C by it self (mine is on a 20 amp breaker, so 20 amps times 120 volts equal 2400 watts.
I've ran a 4000 watt non inverter Champion Generator for the last 6 years. It cost me about $250 in 2012. It's run flawlessly, all I've ever had to do is change the electric start battery once and change the oil a couple of times. In stock form the Champion generator runs at 68 decibels, and to further quiet it down I routed the exhaust through a stock HD Electra Glides stock quiet muffler. That did the trick, now I can stand right next to it and have a normal conversation. Total cost about $300 bucks.
Power is VxA ONLY for the case of a pure resistive load. which an AC motor is NOT. what you care about with a generator is Volt Amps, which is what most generators are rated at. Now, with a Air conditioner motor, VA draw is fortunetely only about 10% more than calculated based on watts. so it's not a bad approximation.
where it falls apart is with things like microwave ovens and most chargers built into an RV. In those cases current draw can be 30% more than what is calculated based on the power (watts) draw.
