Hot Tub Cable and Electrical Wiring

By Dave Rongey - Summary:

How to Install Hot Tub Electrical Circuit Wiring: Can I run regular 6AWG 3 conductor plus ground through a one inch conduit or do I need to run outdoor 6AWG wire?

Hot Tub Circuit Wiring

Electrical Question: Can I run regular 6AWG 3 conductor plus ground through  a one inch conduit or do I need to run outdoor 6AWG wire?

Hot Tub Circuit Wiring –  Project #1

  • I’m installing electrical wiring to the hot tub located in my backyard.
  • I am thinking that regular indoor wire run through conduit is OK.
  • Also, to my understanding, the wire must not be buried and be above ground by at a minimum height.

This electrical question came from: Mike, a Homeowner from San Diego, California.

Hot Tub Circuit Wiring – Project #2

  • I am installing a hot tub in our back yard. I have to run about 45 feet of cable indoors from the primary breaker panel to the outside wall where it will connect to the sub panel with the GFCI shutoff on the outside of the house.
  • When the cable comes out of the house it will be low to the ground, so I can’t go directly into the back of that sub panel, so I will install conduit from where it comes out of the house, and up to the panel which is about 1.5-2ft.
  • Can I use Romex Brand /NMD90 6/3 Type-NM Cable for this? I know  Type-NM Cable is acceptable for indoors, and into the back of the panel on the outside of the wall. But, since the cable has to come out of the house low to the ground it will need to go in conduit and up about 2 feet to the sub panel on the outside wall. Is this okay? If not, what would you recommend?
  • Then from the outside panel and GFCI I’ will use THHN in conduit or direct bury the wire to the hot tub.

This electrical wiring question came from Justin, in Edmonton, Alberta, Canada.

Dave’s Reply:
Thanks for your electrical question Mike.

Methods for Installing Hot Tub Circuit Wiring

Hot Tub GFCI Panel

Application: Wiring a Hot Tub GFCI Circuit.
Skill Level: Intermediate to Advanced – Best installed by a Licensed Electrical Contractor.
Tools Required: Basic Electricians Pouch Hand Tools, Voltage Tester.
Estimated Time: Depends on personal level experience, ability to work with tools and install the hot tub wiring.
IMPORTANT: Installing hot tub circuit wiring must be done according to applicable Local and National Electrical Codes, or Canadian Electrical Codes, with a permit, and the work must be inspected.

Examples of Hot Tub Circuit Wiring Methods

The questions asked about hot tub circuit wiring address methods which I will describe below:

  • Electrical Cable for a Hot Tub
    • 6/3 Romex brand or UF cable cannot be run inside long lengths of one inch conduit.
    • Cable may be installed into a short length of conduit where it is used to stub up out of a trench or where emerging from a protected area such as a crawl space under a house.
      • An insulated bushing mush be installed onto the end of the conduit to protect the cable.
  • Wire and Conduit
    • If you are using long lengths of conduit for the hot tub circuit wiring then you should install four separate conductors, and the type of wire will depend if the conduit will buried or not.
      • Type THWN wire is a good choice because it is rated for buried conduit applications.
  • Using a Junction Box for Hot Tub Wiring
    • When using two types of wire or cable for a hot tub circuit a junction box may be installed in an accessible location where the wires may be spliced.
    • Wire splices must be performed using corrosion inhibitor and approved wire splicing connectors.
  • Permit and Inspections Are Required
    • Do not take shortcuts or take chances. Electrical wiring projects such as this require a permit and inspections from your local building department.
    • Your local building authority will be happy to assist you with your hot tub project.

More about Wiring Hot Tubs

Hot Tub Wiring
Hot Tub Wiring

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  • Electrical Codes and Details for Spa and Hot Tub Wiring.
  • Essentials for your installation, including the required GFCI ground fault protection and circuit wire size.

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Be Careful and Be Safe - Never Work on Energized Circuits!
Consult your Local Building Department about Permits and Inspections for all projects.


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FAQs Frequently Asked Questions and Comments

4 Responses to “Hot Tub Cable and Electrical Wiring”
  1. Dave Rongey says:

    Hi Gary,
    An estimate to extend the circuit wiring of a hot tub to a new location would require an on site evaluation where an electrician in your area could see the existing circuit wiring and then propose the best methods to would use to extend the circuit. The project may be estimated with the time and materials necessary, which may include an approved junction box, and supported electrical conduit to protect the circuit wiring. The actual cost for the project will depend on your location, the current rate charged by the approved electrician, and he cost of materials.
    Thanks for sharing your project with us Gary,

  2. Gary clark says:

    I’m inquiring as how much it would cost to rewire my hot tub as I’m moving it 6-7 feet from its current position and require a quote. Yours, Gary

  3. Dave Rongey says:

    Hi JB,
    Electrical wiring and components must be protected according to code, specific to the project location. Typically a GFCI protected circuit for an outdoor spa is installed with a permit and according to applicable codes, and the wiring is installed in an electrical conduit using water proof fittings and methods and the installation is inspected.
    Be Safe,

  4. j barbree says:

    Should I use conduit when wiring for an outdoor spa?


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