I have had issues with my A/C, batteries, and other miscellaneous electrical items. The previous owner told me he was running 2 power inputs. One 30 amp, and one 50 amp. He had a window A/C, and a portable unit. He didn't repair the rooftop A/C. The trailer was basically what I was looking for, and I told him "No Sale" without the rooftop unit working correctly. He put a new one up there and provided the paperwork. I never re-installed the window unit, as I have the portable, and the rooftop unit working. I soon discovered when it was 110ยฐ + outside, and both units running, the main 30 amp circuit breaker would pop. So I had to run an extension cord to a receptacle on the garage. This worked fine, but I still felt something was not right. Too much voltage drop inside the trailer with the A/C running. 120.3V without, and 111V with. Then the 20 amp breaker for the extension cord popped. Oh no, not good. I determined there was an issue with the garage wiring. All that is on that particular breaker is 4 gang receptacles and 3 fluorescent lights. Lights are rarely used, and a small refrigerator is plugged in, as well as my portable A/C. I disconnected everything to verify if these devices were or were not an issue.
So, in the course of finding the cause of the popping breaker, I discovered the RV receptacle was wired into one of the sub panel breakers, just not the one popping.
Now after all the previous background story, I found that the person who did this wiring, installed an 86 foot run of 14 AWG wire, with several junctions. At the sub panel is a 50 amp RV receptacle that is now being used for a compressor. That double pole breaker, and the 30 amp breaker for the RV receptacle are the wrong ones. They do not fit the panel. The clip that is on the buss barely clips on. The metal cover over the breakers won't fit because of this.
Note the 3 breakers on the right, just above the word "ON/I".