Hot Tub - ECN Electrical Forums

I received a call from a friend that is getting a small tingle when she gets into the hot tub. Since I have never installed nor worked on a hot tub, I was looking for ideas about the things I need to look for when I get there.

Thanks, Keith

Check the size of the ground that is bonding the tub. I can't tell you how many times I've seen hackers out there use a #10 or even #12 ground. Darn near every modern hot tub needs a #6 ground (assuming 50A being brought in over 3 #6 wires). Obviously the GFCI is not working properly either (one could argue that the tingle isn't enough to trip it I suppose -- heck, a lot of hackers ignore the GFCI with the thought that "hey, it works without it"). The most glaring issue here is that there is a loose hot wire that is shorted to a metal water pipe, thus energizing the water (I'm assuming that the tingle is felt when she is making contact with the water).

Also check the ground on the hot water heater if you don't find the problem in other areas.

I would also suggest looking for a _neutral_ to ground fault somewhere. This can inject considerable current into the ground system without tripping any breakers.

I would suggest using a meter in the area of the hot tub to try to find the potential difference which is causing the shock, and then turning off circuits until this potential goes away.

-Jon

Calsparky,

Before you start calling people hackers for installing less than a #6 EGC for a 50 amp circuit please take a look at Table 251.122. Do you know what the purpose of the EGC is?

Curt

Also check the main service coming into the house. Got a call from one of my GC's while he was on vacation during the last hurricane. The same tingling was happening to him and it turned out that the main neutral was loose at the pole. TELL THEM TO STAY OUT TILL YOU GET THERE!

Whole bunch of reasons one could feel a tingle, I say bonding rather than grounding. Two different items.... But I would handle in the manner winne proposed.

680.42C "Interior Wiring to Outdoor Installations. In the interior of a one-family dwelling or in the interior of another building or structure associated with a one-family dwelling, any of the wiring methods recognized in Chapter 3 of this Code that contain a copper equipment grounding conductor that is insulated or enclosed within the outer sheath of the wiring method and not smaller than 12 AWG shall be permitted to be used for the connection to motor, heating, and control loads that are part of a self-contained spa or hot tub, or a packaged spa or hot tub equipment assembly...." Assuming it's 20A!

Bonding different story... 680.26A "Performance. The bonding required by this section shall be installed to eliminate voltage gradients in the pool area as prescribed.

FPN:This section does not require that the 8 AWG or larger solid copper bonding conductor be extended or attached to any remote panelboard, service equipment, or any electrode."

680.26B,1-5 #8 solid min.

1. Before turning the power off, try to measure for voltage in various locations. Record your findings on paper, as it is always too easy to forget exactly what you found and where you found it.

2. Now turn the power off that feeds the Jacuzzi and see if you still get readings (supposing you did find voltage somewhere at the jacuzzi).

If you are getting readings with the power turned off, the problem is in the bonding.
If you do not get readings with the power off, most likely there is a problem with the feed to this jacuzzi.

Let us know what you find [Linked Image]

Pierre

I had a call a while back;custumer catching buzz while entering hot tub.
I got to job,sank one lead of my fluke in the h2o and the other to a good ground. Water was energized 120v. Custumer had wireed from disconnect to tub and did not connect grounding conductor nor did he have gfci protection. Did`nt know what the extra wire was for, he said.Good thing the kids didnt get a hold of a good ground while getting in.

Re;grounding size.
I got poped a few years ago on a spa circuit.the wise inspector noticed the sticker the spa manuf had at the control panel; min wire size # 6.This sticker has been on most balboa control panels arround here,which he required the # 6 on all conductors. scince that day I run a # 4 SER al,which has the # 6 al grounding co, to the GFCI disco. Then copper # 6`s to the spa.Or Pipe the whole run and run 6 thhn.
If its .
One last thing;Trying to connect the # 6 to the termination point on those balboa controls is always a joy.Obviously the manuf had never had to connect the wires up to such a tight space.What a joke.

Ore,
Yes the tub maker usually requires the #6 ,and we have found jobs with #10 or 8, I guess the mfg. just had a lot of extra ink, so they printed the label. We have a lot of Hot tub installers, that don't understand Mfg. instructions, and not the code section apply.
And yes that connection is always in a tight spot.

[This message has been edited by LK (edited 09-02-2004).]

OK Here goes the results! This tub is feed buy a 4 wire feed, 100amp subpanel, 50 amp gfci to tub, 2-20 amp gfcis for recpticles.

Breaker to tub on!
18v wster to concrete pad
16v water to earth around pad

Breaker to tub off!
Same voltage

Ground lug in sub panel to earth+ 12v.

Went iside to main panel and killed subpanel feed. Still 12v from ground lug to earth.
Removed panel cover and found seperate ground and neturals. no voltage between ground and netural. Went to meter base, killed house power. Still 12v to earth from ground lug. Netural and ground bonded inside meter base. Checked from ground wire to earth. 3v. Called poco. Lineman shows up, checks same things I did. Same results.
House is fed from underground. He went to xformer, removed feeds and rechecked everything. Voltage 0, Reconnect feed to house voltage returned. He tightened feeds and neturals. Said he had to turn this over to there engineer. Still have voltage in water. Other oputside recepticles read 3-4 volts to the earth.

Thats where I stand now, waiting on poco!
Keith

Sounds like stray voltage.

1. disconnect the GEC from the cold water and the ground rod if there is a ground rod. now check the load side.

2. if the load side has no voltage, that means that the neighbor has a problem at their house. The neighbor that is connected to the same POCO transformer.

Pierre

Facinating!

Does this tub or house have the Xformer feed or other Service lat's running though the property in some way? Maybe damage there water line and ground rod stuck in it? [Linked Image]

Or may the lack of a water line and rod....

Still have a grounding and bonding issue though. The ground issue may belong to the POCO, and at this Service. But I would still definiatley bond the ground lug of the hot tub to that pad its on. Or any other conductive surface associated with getting in or out of it. (technically 5 feet around it)As so far this is the highest potential to earth on the system now, for whatever reason. Bust the pad to exose some rebar, and bond it to the the tub motor or ground lug.

Quote

680.26B,1 Metallic Structural Components. All metallic parts of the pool structure, including the reinforcing metal of the pool shell, coping stones, and deck, shall be bonded. The usual steel tie wires shall be considered suitable for bonding the reinforcing steel together, and welding or special clamping shall not be required. These tie wires shall be made tight. If reinforcing steel is effectively insulated by an encapsulating nonconductive compound at the time of manufacture and installation, it shall not be required to be bonded. Where reinforcing steel is encapsulated with a nonconductive compound, provisions shall be made for an alternate means to eliminate voltage gradients that would otherwise be provided by unencapsulated, bonded reinforcing steel.

Quote

Article 680 applies to decorative pools and fountains; swimming, wading, and wave pools; therapeutic tubs and tanks; hot tubs; spas; hydromassage bathtubs; and similar installations. The installations covered by this article can be indoors or outdoors, permanent or storable, and may or may not be directly supplied by electrical circuits of any nature.
Studies conducted by Underwriters Laboratories, various manufacturers, and others indicate that a person in a swimming pool can receive a severe electric shock by reaching over and touching the energized casing of a faulty appliance — such as a radio or a hair dryer — as the person's body establishes a conductive path through the water to earth. Also, a person not in contact with a faulty appliance or any grounded object can receive an electric shock and be rendered immobile by a potential gradient in the water itself. Accordingly, the requirements of Article 680 covering effective bonding and grounding, installation of receptacles and luminaires, use of ground-fault circuit interrupters, modified wiring methods, and so on, apply not only to the installation of the pool but also to installations and equipment adjacent to or associated with the pool.

[This message has been edited by e57 (edited 09-03-2004).]