Is it okay to run a 15 on a 20? I know the opposite will short out the circuit, but is there any way of damaging the 15 amp plug-in (air bathtub) by running it on a 20 amp breaker? The breaker is 20 amp goin outta the box. Would it be best to get a 15 amp gfci for the new outlet, or should I run a 20? Either way, just another trip back to HD!

 

It is legal in the US to have a 120 volt 15 amp receptacle on a 120 volt 20 amp circuit (unless local laws do not allow this). In Canada this is not allowed. In the US most 120 volt 20 amp circuits have 15 amp receptacles.

Having a 20 amp receptacle on a 15 amp circuit will not short out the circuit. It is however a code violation and presents a dangerous situation.

I don't know exactly what you are referring to, but the unit most likely calls for GFCI protection. In a bathroom GFCI protection is required by code. If this receptacle is not GFCI protected then by all means go get a GFCI receptacle. However, if the breaker is GFCI or if there is GFCI protection provided come other way then you can use a regular (non-GFCI) receptacle.

One other caveat. If this device states that it requires a dedicated circuit, then you need to provide a dedicated circuit. While it might run on a non-dedicated circuit, it will trip if you load the circuit too heavily. Plus, if the direction call for it, it's required.

 

The vast majority of installations in the US are 15A receptacles on 20A circuits.

If you already have a 20A receptacle on a 15A circuit, it's not really dangerous, per se; just make sure it is still a 15A breaker. 15A plugs are still designed to work in these.

When was the last time you actually saw a 20A plug on a 120V tool? Not very common, but at least be aware of what you have and what you put into it.

As Racraft states, though, you might as well do it correctly, since you seem able to do so easily.

 

I'm hearing both of you, but seems like the instructions on the airbath, not a jacuzzi, have it with a 1 hp motor and from what I would guess, a small draw. In the setup instructions in one place it calls for a 15 amp gfci, that it must be grounded and must be tested occasionally. In another place it says it would need an independant circuit. Kinda conflicting info, huh? My breaker box is all gfci protected and very complicated looking. I guess what I'd like to know is will the 15 amp gfci outlet on the 20 amp circuit, which by the way does have other outlets tied to it ( computer, tv, stereo ), be okay to use for the airbath. In the first reply Racraft said that I wouldn't want to trip the circuit by having too much going at the same time. Is that the only concern other than TRYING to follow the manufactures instructions...thanks...

 

This information is not conflicting. They are saying two things.

The first sentence calls for a 15 amp GFCI protected circuit. The second item says that this circuit must be independent. Nothing conflicting about those requirements at all.

Attempting to use an existing circuit for this is a bad idea. Not only does it violate code, but you will risk damaging your computer, TV, stereo and whatever else electronic you have on this circuit when running the 1 HP motor.

This installation calls for a new 20 amp circuit, dedicated to the device. Period. No exceptions.



While your box may look complicated, I doubt very much that it is "all gfci protected". This would be very unusual indeed.

 

Use a 20A GFCI breaker, and a T-slot simplex 15/20A recepticle. All will be legal.