Cord Connected Hot Tub for Display Purposes

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davelectric

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I am installing power for Hot Tubs that will be on display and filled with water in an indoor retail showroom. There is the possibility of a customer getting in and trying out the spa once and a while. They are 240/120 volt 60 amp. They do not give you actual load just 60 amp circuit required. Because the spas are constantly being moved and changed out for different models, we would like to use a 6/4 SO cord to a 60 amp 3R receptacle enclosure. The cord would not be fastened to the structure and be about 25 ft long to allow for different scenerios. The outlet of course would be on a GFCI breaker. I realize this is not an approved wiring method for an indoor installation but is there any exception that would allow this for display purposes. What about 400.7 (6) utilization equipment permitted for frequent change?
I sized the cord for 55 amp 400.5(A) column B based on the fact that the spa, worst case would pull 80% of the 60 amp that the manufacturer rate it at. (125 % of 48 amp = 60 amp)
Any thoughts?
 
Dennis Alwon

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
The only exception for cord and plug is in 680.43 for tubs rated 20 amps or less. Personally I would run this by the AHJ and see what they say. Also there is no exception for equipotential bonding indoors either unless you can use the 2011 TIA.

The only other means would be to use art. 590 for temporary installations. I am not sure if that would qualify.
 
renosteinke

renosteinke

Senior Member
Location
NE Arkansas
This sounds like exactly the sort of situation where 'temporary' installations are recognized. However ....

I see a real problem in attaching the cord to the tub in a way that provides the necessary strain relief. Most tubs simply have an opening where the pipe can stub up from the ground, without any real attachment to the tub.

Here's a thought .... please tell me the showroom has a 'hard' floor, rather than carpet ....

Make a pallet and set the tub on that pallet. The pallet can have a metal plate to mount the cord strain relief. The entire pallet can be mounted to those ball-type conveyor rollers. THOSE you can bond to make the EGP.
 
renosteinke

renosteinke

Senior Member
Location
NE Arkansas
Amazing what happens during lunch ....

I had just called the missus, asking her to power up the hot tub, as I would like to have a long soak. It's raining here, and I can feel the chill- just what a good soak will cure. You see, my tub has electric heat, and can only raise the temp about 6 degrees / hr; that means it needs several hours to reach temp.

That's when it hit me ...

There is no way to justify a 'temporary' set-up for a tub on the display floor. Nor is there any way to connect a cord to the tub. The best you can do is stub up from the floor with the usual conductors, and lay a grid under the carpet. It will take significant time to fill, heat, and drain a tub. Even if it were on wheels, I'd hate to try to move it around!

What I think we have, instead, is a merchant in a rental storefront who is trying to avoid making any alterations to the building. If so, that's just his superstitious fear that doing it 'right' will be disruptive and expensive; I'm confident his lease allows this work.

Perhaps he simply needs some explanations as to exactly what the job entails. There's no reason that you can't have a local disconnect (the 'spa panel') feeding a pipe that runs on the surface. The tubs will have to be fed from underneath - he's not going to want to damage the unit - and terminating 4 lengths of THHN isn't much different than terminating the fine stranded stuff in an SO cord. The tub will have to sit on a platform, but having a platform built will make adding an equipotential grid a piece of cake.

Another 'plus' is that this will give the dealer a way to show the customer the way such tubs are supposed to be installed.
 
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blargh

Member
Location
Redwood City, CA
Occupation
Design Engineer
A disconnect with a short whip of LFNC would seem to be the appropriate solution, and really no harder to remove power nor to hook up than the proposed cord option.
 
Dennis Alwon

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
There is no reason a display room needs to fill the hot tub with water, IMO. If they want people in it then do it to code.
 
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