Efficiency of 120 Hot tub vs 208/240

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a ground fault will open the circuit if there is a fault, they are also a lot cheaper than a funeral
 
wireman71 said:
I bought a hot tub that is configured for both voltages so I'm deciding which one to wire for. Would a 120 volt circuit use anymore wattage than a 208/240 circuit? I'm thinking no. If this is true then is 277 volt lighting any more efficient that 120 volt or can you just put more lights on a circuit? Next my manual mentions GFCI protection if you go the 208/240 volt route but doesn't mention it for the 120 volt setup. I personaly don't see a issue with not having a GFCI for my personal hot tub as I don't see the potential for shock with a functioning ground connected. And my code book is 2002. Only requirements I see are a disconnect within site(residential) and a service recept 5-10 feet away for service.
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Efficiency and voltage has nothing to do with each other, in this case.

You can certainly install more than double of the fixtures of the same wattage on a say 20 A circuit when changing system voltage from 120 to 277. This has nothing to do with efficiency either but it will use less copper. (Unless you use aluminum wiring ;P)

I would not get into a hot tub of any voltage above 24V if it does not have a GFCI protected feed...Just my personal opinion though. Don't forget that the NEC is the minimum, you can install above and beyond its requirements. If you look at the GF protection history in the NEC, the GF use requirement is becomiong more and more widespread. Did physics change? No. Does that mean that an installation that was perfectly legal 10 years ago can kill you today? Yes.

I dunno, it defies my logic though....
 
wireman71 said:
I'm still on the fence on the GFCI issue.. Does the water normally have conductivity to the ground?
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I'm of the opinion that a major concern is what might happen if the water itself becomes energized, due to an insulation breakdown somewhere in the tub's equipment, and someone contacts a grounded surface outside the tub.
 
weressl said:
Did physics change? No. Does that mean that an installation that was perfectly legal 10 years ago can kill you today? Yes.
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Use of seatbelts in motor vehicles, which is almost universally a legal requirement now, wasn't always so. In fact, they didn't even come in cars for many years, and were optional for many.
 
Most hot tub heater elements are enclosed within a (grounded) stainless steel chamber to minimize the possibility of any shock hazard. If the heater element were to fail, and leak current into the water. That grounded sleeve captures the escaped current before it can get to the occupants of the tub, preventing an electrical shock.

I've changed literally dozens of hot tub heater elements that were blistered open, leaking all kinds of current into the water, yet no one had experienced any kind of electrical shock. The stainless steel pipe sleeve encasing the element did its job.

Many of the newer hot tubs have in their instruction manuals directions to use only GFI protected circuits when wiring them. This means that even if the Code does not specifically require a GFI breaker elsewhere, it is nevertheless required due to the provisions of 110.3.
 
kbsparky said:
That grounded sleeve captures the escaped current before it can get to the occupants of the tub,
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It can certainly take some current but it can't stop the current.

The current will take all available paths, not just the path of least resistance.

But as you said no one seems to be getting shocks.:smile:
 
Yeah, those are the older type of spa/tubs, with a GFI built-in protecting the control wiring, but not the heating element itself.

I would get a call from the owner complaining that the tub was not heating, and find the element drawing 1.4 Amps on one leg, and 4.5 on the other. All that current was leaking into the water. Removal of the element revealed that it was blistered open --- ruined.

No one ever complained about getting shocked, even though the element was probably leaking current for months or years before blistering open and final failure.

On newer tubs with complete GFI protection provided at the source, the breaker would start tripping long before any blistering of the element could occur. I've replaced dozens of "bad" elements that looked perfectly good, but since they were leaking current, they could not be used due to the "nuisance" tripping of the supply GFI breaker.


On a side note, it's amazing the number of homeowners who assign blame to a bad breaker instead of a possible problem(s) with the hot tub, or its heating element, etc.
 
If your hot tub is outside, where it gets cold, make sure you check up on it once and a while.
I used to have a hot tub, until the GFCI tripped... then I had a 300 gallon ice cube...
I think next time I will rig up some kind of power monitoring (or just use it more often)
 
wasasparky said:
If your hot tub is outside, where it gets cold, make sure you check up on it once and a while.
I used to have a hot tub, until the GFCI tripped... then I had a 300 gallon ice cube...
I think next time I will rig up some kind of power monitoring (or just use it more often)
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Invest in one of these...

GFCI_small2.jpg



They come with a alarm when the GFI trips
 
wasasparky said:
If your hot tub is outside, where it gets cold, make sure you check up on it once and a while.
I used to have a hot tub, until the GFCI tripped... then I had a 300 gallon ice cube...
I think next time I will rig up some kind of power monitoring (or just use it more often)
Click to expand...

Many tubs allow for a second control panel to be mounted remotely, or indoors. Usually, the interconnect is just a cat-5 cable.
 
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