[theeyres]

You should be able to run the electric heater by itself, if that's what you mean. I have had no trouble in any trailer doing that even with the hot water heater on. But I cannot add the microwave to that or it will trip the service. I can sometimes run the micro with the a/c but it will trip if anything else is on so I don't try. Here is a list from KOA. A/C alone is drawing 1/2 your total amps. Microwave, the same--so you can see you don't have much left.

120 Volt AC Amp Ratings
Appliance or Electronic Equipment Estimated Amps
Air Conditioner (X number of A/C) 12-16 Amps
Blender 5-6 Amps
Coffee Maker 5-8 Amps
Compact Disc Player 1 Amp
Computer (Laptop) 2-3 Amps
Converter 1-8 Amps
Crock Pot 1-2 Amps
Curling Iron <1 Amp
Drill 2-6 Amps
Electric Blanket 0.5-1.5 Amps
Electric Fan 1 Amp
Electric Water Heater 9-13 Amps
Electric Skillet 6-12 Amps
Hair Dryer 5-12 Amps
Iron 5-10 Amps
Light (60 watt % 120V) <1 Amp
Microwave 8-13 Amps
Microwave (Convection Oven) 13 Amps
Refrigerator in AC mode 5-8 Amps
Space Heater 8-13 Amps
Television 1.5-4 Amps
Toaster 7-10 Amps
Vacuum (handheld) 2-6 Amps
VCR 1-2 Amps
Washer/Dryer 14-16Amps

12 Volt DC Amp Ratings
Appliance or Accessory Estimated Amps
Aisle Light 1 Amp
CO Detector 1 Amp
Fluorescent Light 1-2 Amps
Furnace 10-12 Amps
LP Gas Leak Detector 1 Amp
Overhead lights (Per Bulb) 1 Amp
Porch Light 1 Amp
Power Roof Vent 1.5 Amps
Radio/Stereo 4 Amps
Range Hood (Fan & Light) 2-3 Amps
Refrigerator (LP Gas Mode) 1.5- 2 Amps
Security System 1 Amp
Television (12 volt) 4-5 Amps
TV Antenna Booster <1 Amp
TV Antenna Booster 12 Volt outlet Up to 8 Amps
Variable Speed Ceiling / Vent Fan 4 Amps
VCR Recorder / Player 2 Amps
Water Pump 4 Amp
Hopefully this clears up any confusion on the difference between using amps supplied by the campground electrical source (AC amps), and using amps supplied by the converter (DC Amps).

Happy Camping!