Unfortunately we have nothing to tell us if this lock will fit a 2015 ace thor motorhome 30.1. You would need to go based on the cut-out and dimensions. The Bauer em is used on many motorhomes and the NE is used on many trailers, but can be used on either depending on the cut-out. Below is the cut out and over all dimensions for the EM model. Click to enlarge photo. Requires a 4.88" W x 4.50" H cutout.