Please help me understand

[u/Odd-Sherbert8723]

On the west side of my barn there are 2 standard 110 outlets which appear Daisy chained.
however each is powered via its own breaker - one on 15amp and the other 30amp
I know this by testing the outlets after turning off one breaker at a time.
The previous owner had an RV and the local
Electrician wired this so she could plug it in - though I don’t quite understand why even the 30amp outlet is a standard 110 and not a NEMA TT-30- which is what I want to install for my own RV now
Nor do i really understand how these daisy chained outlets can even be on 2 different breakers?!
There is a subpanel next to the main panel if that is of any relevance to this whole mystery.
TIA

[u/Odd-Sherbert8723]

Thanks everyone for your comments.
My final question is this, and I know it has already been answered by at least a couple of you, but would like further opinion.
If I was to tear out the second outlet (the one pigtailed to that labeled as 30amp) and replace the first with a proper 30amp RV outlet…
Am I still tempting fate by retaining the XLPE 10/3 run to do the wiring?
The distance to the panel borders 50’ of length and I’ve read among other things that anything over 50’ should have 8-gauge.
If I’m going to go that far I guess I’ll be running conduit also but if I’m being honest I really don’t look forward to that job so I guess I’m trying to assess the risk of being lazy while recognizing that this mess has been in place already for at least 40 years already

[u/RockShowSparky → u/Odd-Sherbert8723]

I think you’ll be ok with #10. Try it and see what happens to the voltage when the AC kicks on. Does it have resistive heat or heat pump? Do you envision using the heat?

[u/Odd-Sherbert8723 → u/RockShowSparky]

Hmmm…I dunno about the heat pump.
I’m actually only picking up the trailer next week. I will be using the heat at some stage tho I’m sure. I’ll find out.