[GenKnot]

What generator?

 

[GenKnot]

Can I run the generator with three regulators in series?

No

Or do I have to remove one of the regulators?

If the demand flow regulator/valve can be removed from the 2-stage regulator(s), then you can hook up to the already reduced propane pressure lines in your camper's propane system. The demand valve operates on low pressure LP gas coming in, and then meters the LP out to the carb by sensing carb vacuum (which is the demand).

If you have questions, post a photo of the Champion LP hose and regulators that came with the gen.

 

[GenKnot]

I should take the dual-stage regulator out and connect the demand-flow regulator directly to my propane distribution system (which is already regulated at my tanks). See attached photo. Thanks for the suggestion. I will do this later in the week and post my results. Any suggestion of where I can get fittings to help make this happen?

Yes, connect the demand valve directly to your LP system.

You may want to use a quick connect setup like this guy made (and he shows the parts he used):

https://www.irv2.com/forums/f93/champion-3400-dual-fuel-on-rv-propane-system-344289.html

 

[GenKnot]

AND he shows how well it works running his camper's AC

Yes, and it started his A/C even though the gen was in ECO mode. If your A/C will not start with gen in ECO mode, you may have to take the gen out of ECO mode. If the A/C will still not start, you may need a soft start installed on it.