Originally Posted by BL1996
Crain RV told me not to run the inverter when running the generator and the A/C.
Actually, Crain RV is right.
First of all, there is no point in running both the generator and the inverter. You might as well put the inverter/charger on "Charge Only" when running the generator, because charging the house batteries is all it's doing anyway.
The key here is that you can only run on one
AC source at a time.
1 - If you've got shore power hooked up and the generator turned off, all of your AC power comes from the shore power.
2 - If you're running the generator and don't have shore power plugged in, all of your AC power comes from the generator.
3 - If you've got BOTH shore power hooked up and generator running, you're using power from the generator only. The shore power cable is giving you nothing. Even though the generator output is 20amp vs. 30amp from shore power. That's the way the ATS is set up. I think that's backwards from how it should be, but I've confirmed that's the way Interstates are wired.
4 - The only way you're using the inverter to get AC power from the batteries is if you have neither shore power nor generator providing AC power, and you have it set to "Invert."
Here's a link to one company that makes a "night system" for semis:
Semi Truck Air Conditioning & Heating, HVAC Systems for Trucks, King-Air
They need a lot more amp-hours than an Interstate's house batteries will provide, and some units are the same BTUs as what an Airstream Interstate already has on its roof. In other words, if you had enough amp-hours for a night system, you'd have enough to run your rooftop AC on inverter as well and wouldn't need the night system.
To cap off the installation, you would need a second alternator on the engine, with a voltage regulator designed for AGM batteries (or at least a second voltage regulator hooked up to the existing alternator), to recharge the battery bank while driving down the road. Which actually isn't a bad option for a standard house system anyway. Sure would help boondockers!