I used to do it just like this, it works fine...but it is critical that you disable the onboard converter when doing so. Otherwise the converter gets energized by the 120V AC from the inverter and it tries to do its job of providing 12V DC charging. This will cause it to try and charge the 12V DC batteries while also drawing power from the batteries via the inverter. An energy draining loop is created...
On my TT, the converter AC input was pigtailed into the AC breaker (GEN). I bought another AC breaker from the hardware store, popped it into an available slot in the AC board, and removed the converter power input from the GEN pigtail and wired it to the new breaker. Then I used that breaker as an on/off switch for the converter. You'll have to investigate how your converter is powered and find a way to disconnect it.
Also note that your whole camper 120V AC system will think shore power is available, so don't use things that are beyond your inverter/battery capacity or it will overload the inverter. Make sure a propane fridge is on gas only, water heater on gas, don't use the air conditioner or microwave or other high-draw AC items.
Alright thank you I'll give it a try, I won't be using the water I have to fix all the plumbing stuff the only think I need to work is the wall outlets for my small tv mini fridge sometimes my microwave(when needed) and I have a small ac unit I use for the summer and tiny space heater in the winter but I won't have everything plugged in at the same time anyways. I'm still remodeling the whole camper so I don't need much all at once I just wanted to know if it was okay or possible to plug the cord into that kind of power system instead of a house or campground kind of system. Until I can get the solar panel system hooked up properly.
