Circut breaker question

Would not be good for it. The TT is rated for 30 amp service. If you want 50 amp usage you would need to change out the 30amp box for a 50 amp box and do some rewiring. Her solution to avoid that is to plug in the new AC directly to the power stand outside on a seperate circuit. Most power poles have a 30 amp, 50 amp and also a 15 amp service there on the pole.

She could run an extension cord from the power pedestal to the new AC unit. Needs a healthy 312 extension cord for best results.
Not a good idea to try to overload existing trailer electrical system.

"If she used an adapter and plugged into 50amp would that cause damage to the trailers electrical system."
No, the input breaker on the trailer system would be a 30 amp breaker and would trip if the trailer (2nd AC unit) plus other things tried to pull more than the 30 amps.

Ken

Like has been said, the 30 amp breaker inside the trailer will trip so it won't work. Like has been said, the only two solutions are to run an extension cord from the power pedestal to the second A/C, or to upgrade the trailer's power supply from 30 amp to 50 amp. Option two is neither cheap nor easy.

Good chance that the rig has no main 30 amp breaker.

Best bet is power the second AC with an available extra outlet on the pedestal. If there isn't an additional 110 outlet, something like this can be plugged into an available 50 amp plug on the pedestal. Since 50 amps of power will be available consider extension cord with a 20 amp breaker will protect the expensive A/C.

https://smile.amazon.com/EPICORD-Adapter-TT-30P-Female-handle/dp/B07KYKWP6B/ref=sr_1_1_sspa?dchild=1&keywords=50+amp+rv+splitter&qid=1590775993&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExTUNJT0pHTVhKQ1Q4JmVuY3J5cHRlZElkPUEwNDY3NzI1REk0R1ozTlAxNTYwJmVuY3J5cHRlZEFkSWQ9QTA3MjQ0ODEzSFNJUDIzWkJaQzg0JndpZGdldE5hbWU9c3BfYXRmJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

All RV have a main Breaker.

enblethen wrote:
Good chance that the rig has no main 30 amp breaker.

Really? What RVs have you been looking at? Every RV I've ever owned, worked on, or looked at in the last 20 years has had a main breaker.

OP, there's nothing wrong with plugging a 30 amp RV into a 50 amp outlet using an adapter. Many people do it all the time. However, it won't help the situation at all. Any load above 30 amps will still trip the main RV breaker.

Thanks for all the input, Your information is the same as I gave my granddaughter. Just talked to her, problem is there is no 110 outlet on the post outside her trailer. Youall have a cool summer.

No main breaker is required. Main is required if it requires more then six operations to disconnect power.
My Pace Arrow does not have a main!