[rohrmann]

Be very careful!! That you are asking indicates you are not real familiar with electricity. Unless that 30 amp outlet wired in your house was specifically installed for you trailer, most likely it is really a 240 volt outlet for a dryer or some other appliance. An outlet wired for your trailer will have one 120 volt pole, a neutral, and a ground in the proper positions. I would recommend testing the outlet with a voltmeter, or having someone who knows what they are doing, or an electrician.