Now comes the fun part, attracting the Power pv wire. Most in the large units require 50 Amps of 240 Volt power. To that intends need #6 THHN stranded copper wiring. You will need four (4) pieces each and every of two runs. Off of the main panel to GFCI then GFCI to spa. Be very careful to measure accurately, Measure from the inside top belonging to the main...