Are you trying to run both ACs at the same time? If so, I am guessing your power center shut off AC 2. Many of them will do that when plugged into 30 amp, I know mine will).
As far as smoke with the heat strip, you should check to see if the install monkey left the glue and/or paper tag attached. I know on our old trailer, we ran into that problem and had a little smoke. I took the thing apart (the air handler had to come off) to find a charred label and burned label glue...
Current TV:'14 F350 Lariat CrewCab, 4x4 Short Bed SRW Diesel w/ Pullrite 2700 (16K)
Current Fiver: '15 Puma 295BHSS Anniversary Edition
Past TV: '13 F150 HD Payload SCrew EB, '08 Tundra CrewMax 5.7L, '02 'Burb 5.3L, '97 Dakota 3.9L
Past Trailers: '09 Wildwood LE 27RB, '02 Palomino Yearling RL, '87 Jayco 1006dlx