lol I think maybe this baby needs to be put down for a nap myself.
The Surge Gaurd 50amp surge protector has a monitor panel that displays two incoming lines of amps. That is where I get my amp usage information. It also tracks incoming AC volts.
My RS3000 xantrex inverter also displays the information of amps on both lines. The RS3000 is 50amps and is on a 50 amp breaker. It is not wired to everything in the coach however. So sometimes there is different amps being drawn thru the inverter compared to the entire coach. But the surge guard does a good job of tracking that information anyway.
Now when I am pluged into shore power 50amps or when I run my Genny I get to see how many amps I am drawing on lines 1 and 2.
If I have both AC's running and the inverter/charger is pulling power to charge batteries and then the hot water heater is on electric and we run some tv's and hit the microwave then I often will see a combined amp usage of over 50 amps. No breaker gets thrown because each line is drawing less than 50amps each.
120vac at 60hertz will change polarity 1/sec the sinewave goes high then low in one second. One could also say that it changes directions once every half second. Its 6 of one or 1/2 a dozen of the other. It depends how you want to say it.
The reason a 30amp or even a 50amp rv can not be pluged into a 30amp dryer plug is because it is wired at 240vac and the rv is wired for 120vac and you would have a major melt down if one did that.
A stove outlet is 50amps and wired for 240vac however it has 2 legs that are 120vac and that should be able to work if one would plug there rv into it. Somehow that makes me uncomfortable and I personally would not do it. But I could because both the surge guard and the inverter have sencing capability and would not let electricity in if it was not wired correctly.
As far as your formula P/E=I, I thought it was P=IxE lol
just kidding.
The inverter losses some P because of heat loss so the actual amps out would be less by 9% or so. I have 4 12vdc deep cycle batteries and have never tried to draw max power from them. Unless you want to count trying to drive the one overhead AC with them. That only worked for about 5 minutes and it was an experiment that failed. But thats another thread.
As far as a power management system goes. I don't really have one. My equipment will just shut things down if I draw to much. Most times its a breaker. So I am the power manager for the coach. But I do have some nice gagets to help me manage things better.
Thanks for all your responses I think we gave a lot more info than the original poster really wanted. lol Sorry for all the ravings everyone.
I hope everyone had a great Christmas and will have a safe and happy new years.
As soon as Frieghtliner gives me back my coach I will be ready to go camping again.