Power Requirements: 115 VAC or 230 VAC +/- 10% @ 50 / 60 Hz (user selectable). The XPR-5 requires a 20 Amp circuit and standard IEC 20 Amp outlet (which is different than a 15 Amp outlet).If you don’t have a proper circuit and outlet, we recommend you have one installed by a qualified electrician.We recommend that the XPR-5 be plugged into its own dedicated 20 Amp circuit. From http://shop.emotiva.com/collections/amplifiers/products/xpr5
The Axiom amps are designed for standard 15 amp circuit. That probably explains the discrepancy.
EDIT: In fact, all the XPRs require a 20 amp circuit. Better add the install cost of that puppy to your total amp price!