Hot tub getting a small shock

[fzbuilder]

Hello all, I have a older 120v spa that overnight developed a short. The spa is on a cement slab and if I stand on the cement barefooted, I get a shock like tingling in the fingers. When I turn on the pump, it gets a bit worse. I have a GFCI and tested it with a ground tester and all good. I went one by one and unplugged the heater, the circ pump and then finally the main pump. Still getting a small shock. Any help would be appreciated.

The only thing I have done since yesterday is to add muriatic acid to get my TA down. I added about a cup last night, ran the jets for a few and covered it up.

[Red Green]

fzbuilder wrote in news:06e75f1a-4818-4e8e- [e-mail]:

Don't you think considering water, lethal electricity levels, existing short...in the water...where heartbeats are immersed that a certified electrician is justified?

Kill the breaker(s) at the panel box and call an electrician. Live a little longer.

[RBM]

Is the GFCI an integral part of the unit or is it on the house with a cord and plug from the tub? If the GFCI is functioning, you would only get a shock from a ground leak on the line side of the interrupter. It's also possible that the gfci is not wired correctly.

[William Munny]

Nah, he won't do that, he's not a wuss-pussy...

[Doug Miller]

I'd say it's *likely*, not just "possible", that the GFCI is not wired correctly -- or that it's defective.

[RBM]

I'm trying to determine if the unit has integral gfci protection, that's cord connected to a non gfci outlet. If this is the case, it could be grounding prior to the protection

[fzbuilder]

ote:

.

I have a GFCI tester that shows it is wired right and yes it is a plug in the wall type, like I said it just happened overnight. I just swaped out the GFCI thinking defect and still get the same problem.

[John Grabowski]

*I'm not sure why the GFI doesn't trip, but one thing I have noticed on older cord powered spas is that the cord degrades. I would check the cord from one end to the other and where it enters the control box. The insulation may have become frayed or dried out and now copper wire is coming in contact with something it is not suppose to.

Maybe try powering the heater, pump, and circulator using an extension cord and see what happens, but leave the main cord unplugged. A continuity checker or a VOM might be useful in this instance. Don't do any work on this in your bare feet.

[RBM]

I have a GFCI tester that shows it is wired right and yes it is a plug in the wall type, like I said it just happened overnight. I just swaped out the GFCI thinking defect and still get the same problem.

You are absolutely sure that the power feeding the gfci is connected to the "line" side of the receptacle? Do you only get the shock when the tub is plugged in?

[fzbuilder]

...

Yes, the other side is taped off. I get the shock with it just plugged in and all(pump motor,circ and heater) are un-pluged from the control box

[stan]

From reading the original question and discussion don't read that the OP has sufficient electrical knowledge to safely trouble shoot this potentially (pun intended!) dangerous situation and needs a fully knowledgeable and competent electrician. Not just someone who does a lot of work or thinks they know what they are doing! Also, BTW check life insurance policy. 120 volts can kill!

[RBM]

Yes, the other side is taped off. I get the shock with it just plugged in and all(pump motor,circ and heater) are un-pluged from the control box.

I would check the grounding conductor in the outlet. Be sure that it's not electrically Hot. I would also check to see if any other circuit in that area, could be grounding into the concrete.

[Stormin Mormon]

He still hasn't told us how the hot tub is being shocked. He just said "he" is being shocked. How is the hot tub being shocked?

[Steve Daniels]

On Mon, 25 May 2009 21:36:08 -0400, against all advice, something compelled "Stormin Mormon" , to say:

It's from all the nudity. Shocked and appalled, it is.

[in2dadark]

I agree. That's one thing I wouldn't be posting online about as my first option..

[jeff_wisnia]

This may sound far out, but have you considered the possibility that there is current leaking through the cement slab from some source and that's why you feel that tingle when you touch the grounded spa?

There have been quite a few dogs electrocuted here in Red Sox Nation in recent years by leakage from defective buried cables making the pavement quite electrically hot in certain spots and much less hot a foot away. There were so many incidences of that a couple of years ago that the pet supply places were selling lots of insulated doggie boots, and the utility companies responsible for the buried cables were looking very bad.

Just a thought....maybe you should try using an ac milliampmeter to see how much current will frow from your finger to a known good ground while you are standing on that same spot on the cement?

Jeff

[E Z Peaces]

Somewhere I've read that dairy cattle can be stressed by the tingle they get from stray currents in a concrete floor. The solution is to bond all the rebar before you pour the concrete.

How about an aluminum pie pan weighted with sand? Wouldn't that be a good pickup to spot check a concrete slab for voltage and current? I'd wear dry rubber soles and not touch other things while touching the pan, just in case more than a tingle is possible.

[John Grabowski]

*That is something worth considering Jeff. It would also explain why the GFI doesn't trip. He could have someone turn off each circuit breaker one at a time and see if the current flow goes away.

[trader4]

Along those same lines, there have been many cases of what is commonly referred to as "stray current", where people get small shocks when stepping into a pool, grabbing something grounded while standing outside, etc. It comes from small amounts of current flowing through the earth from electric utility equipment. There were several stories about it happening here in NJ, with the local utility company actually measuring it, yet unable to precisely identify what was causing it and how to rectify it. If that or similar was happening, it would explain why the GFCI was not tripping. If the concrete was at a slightly different potential than the circuit ground, it would not trip the GFCI.

I'd investigate the service ground for the house and if it's OK, call the electric company out.

[gfretwell]

The legal answer is to either find a way to bond the steel in the slab to the metal parts of the spa or build a non-conductive deck over it,

3' out from the spa or more. Our spa dealer has a PVC deck kit for doing exactly that. It is necessary if you get a permit to set your spa on an existing slab.