We have a 35' 50 amp trailer, but have at times stayed in parks with only 30 amp service. You can manage in hot weather with only 30 amps if you manage your power carefully. When running the A/C you have to be careful of how many other high current devices you use at the same time. Water heater on electric, microwave and/or convection oven, electric skillet, hair dryer, etc. Too many at one time will trip the breaker. No harm done. Just reset the breaker and make a mental note of what you were doing when it tripped.