Based on your 2nd to last picture, the 30amp breaker for you RV is 120v/30amp. There should be 3 wire for this breaker to supply the outlet for the RV(there could be a forth, but you need to remove cover panel to verify) At least two of these wires will be #10 and the third wire should be minimum of #12(one size smaller) or #10 (same as feeder/neutral wires). The colors of the 2) #10 wires are probably red/black, or black/white w/ #10 with a #12 bare copper(or green coated wire).
If this is correct and it is
not supplying any other outlets and you only need 220v and not additional 110v outlets, it can be done.
First you need to purchase a "20/30 quad" breaker that fits the space of the RV and RV breakers. This quad breaker will have a tab that connects the two outside trip levers together, and the two inside breakers will be connected with another tab.
https://www.walmart.com/ip/Siemens-...0699207_10000001836&wl14=quad breaker&veh=sem
https://jet.com/product/detail/024f...ac4d&msclkid=87a7cc8e6739124b335496fd31c44ce1
If you buy the a breaker similar to the first link, then you don't need to do anything to the breaker. If it's similar to the second, then you need to remove the connecting tab between the outside breakers,
not the center tab. You need this tab to make 220v and the purpose of the tab is so that if one leg trips, so does the other.
Your existing frig breaker will be attached to one of the outside pole/breaker, the other outside pole/breaker will not be used. The two inside pole/breakers will be for the 220v to power you brewing devise.
Now, depending on what color wires are for you brewing outlet, it will probably be white/black. If so, remove the white wire from the neutral bar and attach it to one of the two center poles. The black wire will go to the other. Now, using a white colored wire for a hot leg in a panel is not allowed(smaller than #8), so the best thing to do is wrap as much of the wire as you can with red tape. On the other end of the wire where you brewing equipment is, wrap as much of the white wire as you can with red tape.
If your two wires in the panel are black/red or red/black/white then you hook up the ends of the red and black to separate center poles on the breaker. The white won't be used. On the other end where you brewing equipment is those wires would attach to the hot screws on your outlet. Here white won't be used, either.
BTW, there is probably a green wire or bare copper wire going from the sub panel to the brewing equipment. If not, then I can explain that if needed. Also, if you need 120 and 220 in you brewing equipment area, then the above won't work. You will need an additional sub panel near your brewing equipment will need more explanation.
Post a picture of your subpanel with cover off so I/others can see the wires coming in/out of the panel and from the breakers
Oh, Safety First...invest in a decent multimeter. You really need to check your work before plugging in expensive equiptment. I like the digital ones for most applications.
I also left out using a 220v GFI breaker scenario because they are expensive and requires a more time in moving wires and breakers in your existing subpanel.
-Brian
