Learning, Wiring,

What Size Wire for 50 Amp Hot Tub?

Are you struggling to find the right wire size for your 50 amp hot tub? Well, there’s a standard wire size for it!

A 6 AWG American wire gauge is the best 50 amp hot tub option. Moreover, the National Electrical Code recommends using a copper wire to maximize the wire’s capabilities and ensure the user’s safety. Using aluminum wires as an alternative to copper ones is possible. Still, you’ll need to install a circuit breaker beforehand. 

Below, I’ll discuss the proper wire size and which wire material to use for your hot tub. 

Standard Wire Size for 50 Amp Hot Tubs

big hot tub at the home's backyard
Video | Master Spas

According to the National Electrical Code (NEC), the standard wire size for 50 amp hot tubs is a 6 AWG copper wire.

A 6 AWG wire can handle loads of 32 to 60 amps. However, that shouldn’t be the only factor you need to consider. The NEC emphasizes the importance of choosing the right wire material since the same amps the wire can handle depends on it.

Choosing the Right Wire Type for Your Hot Tub

After the wire size, it’s important to consider the right wire material for your hot tub. Electrical wires are commonly made from 2 material types: copper or aluminum. 

Let’s give a bit of background on why wire material is important. Heat is produced as electricity travels through the wire and higher amps requirements results in more heat build-up. The problem is that less electricity can travel through a heated wire due to increased resistance. To counter this, manufacturers use certain materials that can transfer electricity with minimal heat build-up.

Copper wires are the better choice for 50-amp hot tubs.

In particular, a 6 AWG copper wire can safely handle ampacity requirements of 55 to 75 amps – which is more than enough for a lengthy hot tub session. Safety-wise, this is also backed up by the NEC since it adheres to their policy on the maximum load that wires should support.

If copper wires aren’t available, aluminum wires are a good alternative for hot tubs.

6 AWG aluminum wires can support 40 to 55 amps, unlike copper wires. However, it must be supported by an amp breaker. Aluminum wires are notorious for their tendency to overheat during prolonged use – this can be dangerous if you’re using them for power-hungry devices like your hot tub. You’ll need to invest in an amp GFCI breaker to get around this problem. 

Circuit breakers are needed to prevent the aluminum wires from shortening your hot bath session. 

As I mentioned before, aluminum wires tend to overload, so most guidelines for amp services specify using copper ones instead.

However, there is a loophole you can exploit. Aluminum wires can be combined with amp breakers since amp breaks are an external safety feature that detects when the voltage output changes due to overloading or overheating.

All you need to do is access the hot tub spa panel and install a circuit breaker before the wiring. 

The key here is to remember that the standard rule for wiring 50 amp hot tubs is to use a 6 AWG wire, but you do need to consider the wire material to be used. You can proceed with the normal wiring instructions in the hot tub owner’s manual for copper wires. But you’ll need to install a circuit breaker before starting the wiring process for aluminum wires. 


Learn Metrics – 6 AWG Wire Ampacity. https://learnmetrics.com/how-many-watts-can-6-gauge-wire-handle-how-many-amps/ 

National Fire Protection Association. www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=70

Video References 

Master Spas


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About Alex Robertson

AvatarCertifications: B.M.E.
Education: University Of Denver - Mechanical Engineering
Lives In: Denver Colorado

Hi, I’m Alex! I’m a co-founder, content strategist, and writer and a close friend of our co-owner, Sam Orlovsky. I received my Bachelor of Mechanical Engineering (B.M.E.) degree from Denver, where we studied together. My passion for technical and creative writing has led me to help Sam with this project.

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