Ken 15amp breaker from house for shore power is not enough to run air. That is why breaker tripped. Don`t condemn converter (converter changes 110VAC to 12VDC and inverter changes 12VDC to 110VAC) yet. First you must confirm 110VAC to converter. You will need a multimeter to check this. There are several 12 volt
fuses to check, again multimeter comes in handy. You should have 12VDC power on either side of fuse. Place black lead of multimeter on a good ground source and the red lead on either side of the fuses. If you have power only on one side then the fuse is blown. Pull the fuse and it should be visible that the fuse is blown. Check the battery lead connections for corrosion and tightness. Also check the water level in the battery. Use only distilled water to top up. Tap or potable bottled water has too many minerals that will attach to the lead plates in the battery rendering it useless. You can do some quick checks to test 12VDC system. Connect the seven pin harness to your tow vehicle(TV as known here). If you have lights etc. fuse is good. Try boosting the trailer battery with your TV`s battery and booster cables after disconnecting it from 7 pin harness. If you have lights etc fuse is good. If you get lights from 7 pin and from trailer battery and you have 110VAC at univolt converter then yes converter is shot. Most people have replaced these units. My PO changed it before I bought the trailer. I have attached a schematic and testing formula from my 73 service manual for you to look at. Hope this helps.