I clipped this amp draw from one of many websites that have lists of amp draws for common electrical appliances in RV's. The more amps you try to pull the hotter your adapter will become. The breaker is not a fail safe protection device. If the amp draw slowly creeps up on the breakers rating, it is possible to go past the breakers amp rating. As John said, 16 to 17 amps is an appropriate voltage for continuous use on a 20 amp circuit.
Air conditioner 12 - 16
Coffee maker 12
Water heater (electric) 12
Washer/dryer 13
Microwave 8
Convection 15
Refrigerator 3.5
Converter (charging) 8
TV .5-1.0
VCR 0.2
Computer 2
Based on the list of items you want to run, you will running well north of 20 amps. Remember also, if you have any 12 volt appliances or lights on, your converter will kick in and will be another amp draw. Looks like you may get away with the A/C and the computer equipment, that's it.
