I would think eaither you had some other big draws, or something else is wrong. The camper if made that way , should be ok on the 30 amps. Mine is. So, it could be something wonky at the campsite you were at, or something not pluged in all the way. Make sure your conections are good. All of them, even going into the power center. And the plugs on the fridges. It could be a loose wire arching also. And as said above , volt meter and get yourself an ems , not cheap but will save the electronics. Now you have to see if it was the campground you were in or in your camper. Do the easy stuff first, so check conections check each thing individually. Rule stuff out 1 by 1. Pita, but only way to tell.