I am hooking up a new spa. The builder installed a 50A spa disconnect in my backyard and they run 4 (Black, Red, White, Ground) Aluminum Wires from the Main Panel to the Spa Disconnect Box. My spa says to use only Copper Wires. I was wondering if I can use that existing 50A spa disconnect and run Copper wires from it to the spa control box. The lug specifications of the spa disconnect are AL-CU wires. So is this safe? Do I need to run Copper wires from Main Panel to Disconnect instead? Appreciate any feedback.
Thanks,

I've got essentially the same set up. Not sure what my spa requires, but I'm curious what the answer is. My whole house is copper, but for some reason the builder decided to use aluminum for the spa run.