How to Wire a Spa | SpaDepot - Hot Tubs, Spas, Hot Tub How to Wire a Spa. How-to Guides. This guide shows how most 240 volt hot tubs and portable home spas are wired, with photos, a step-by-step hook-up movie & hot tub schematic wiring diagrams. This information is provided to help you to be a more informed consumer. We advise hiring a licensed electrician to wire and install a spa. Hot Tub Wiring Diagram - Ask-The-Electrician This information serves as a typical Spa or Hot Tub wiring diagram to help inform you about the process and electrical wiring components. This article contains general information and does not focus on, or is it specific to one particular make or model. There may be variations between this information and the specific spa you choose to purchase.