As has been said, Load tables for tires are standardized and should be consistent across all brands, assuming the same size/load range. In the absence of having those tables and your actual axle weights (4-corner weights are best), you can use the Federal Tire Info label on your RV (on or near the drivers side door/position) that actually lists your max GAWRs and the pressure needed for those weights using stock size tires.
I can pretty much guarantee that the tire sidewall max is too high for your application, and should not be used. The dealer who sold you the tires should have checked that Federal Tire Info label, NOT simply gone with the max pressure listed on the tire. That's not only lazy, but could even be dangerous.
