Add Main Breaker to sub panel

I have a Square D subpanel in a recreation park model trailer instead of a main panel. Wired up by previous owner. Is it possible to add a Main breaker to this panel? My alternative is to get a whole new panel with a factory installed main breaker. Thanks.

 

Hi My experiences with campers and camp grounds is the camp has a pedestal with usually a 50 amp breaker / outlet to plug into. That would be the "main". So the previous owner added a subpanel to the camper, I did same when we added a huge deck to our seasonal site. IDK if these are all to code , but there are several options you have.
1) you can buy a single master disconnect and add it between your feed from main and subpanel.
2) change the panel as you said
3) keep existing panel, however add a breaker to the panel and route the power feed wires through that breaker, that would be easiest and cheapest. Only cost of a breaker. Again not sure of your codes so you should consult with a licensed electrician.

 

If this is a manufactured trailer the means of disconnect is outside at a pedestal or the meter.

Some panels can accept a main breaker. The number would be needed.