hot tub trouble

[kwired]

Any other docks with electrical equipment nearby. Could easily have been caused by another service having a problem... not the one you are looking at.

Exactly what I have been trying to say to some extent. Bonding the EGC of the tub to the lighting fixture that he had voltage on at one time would have made that voltage disappear - even if there was a problem elsewhere causing that voltage in the first place.

Anything within operator reach of this hot tub (I think code says 5 feet) that is grounded needs to be bonded to the EGC of the tub supply circuit to reduce "touch voltage" potential.

Like I said before, all this bonded together stuff may actually be 1000 volts above "earth" but the fact that it is all at zero potential to each other still subjects the user to no voltage - just like a bird sitting on a power line doesn't feel any shock even though that line may be operating at thousands of volts above ground.

And like you said voltage for the OP may not even be coming from the premises he is working on.

It maybe is coming from a problem with a POCO MGN in a primary line a few miles away even.

 

[sparkyrick]

The hot tub is located on a wood deck with no metal around except a light about 6' away mounted on a wood post 8' away. The voltage reading I was getting was between this metal on this light and the water in the hot tub. Now caint duplicate. Also the light is still wired but hasn't worked in years and off at a switch. I went back several times thru the day hoping to catch a water heater being on or some load different to see if I could duplicate. No luck. Also there is no bond between that light and the spa. All the motors seem to be grounded with grounding electrode and water is grounded, but only by equipment grounding conductor. I think that's ok!

Was the light on? Giving you the voltage reading?

 

[north star]

: - : - :

Was the shock to the users a one time occurrence, or multiple times
and they finally called someone to check it ?......Also, I'm guessing
that the hot tub is a "new" installation.

If you have checked all of the connections that you know to check,
the loose connections [ IMO ] sounds like the probable culprit to me,
but that is only an Armchair Quarterback WAG.

If / when you find the cause, please come back on here and let us
know.

Thanks!

: - : - :

 

[mint402]

Neutral Problems Can Cause

Neutral Problems Can Cause

Echoing earlier posts about problem may be far removed from the hot tub itself....once had a similar issue with a kiddie pool at a Jersey beach club. We had recently performed all the bonding upgrades for pools, spas, etc, and yet some people were feeling "tingles" to step railing at pool. Checked all the bonds, etc......ran some THHN out to the pool area from main EGC and verified all bonds were good....yet still randomly were getting voltage readings from area to the THHN.....started to look for neutral problems....couple hours later noticed possible damage in the overhead utility drop. Turns out the neutral had taken a lightning hit and was mostly severed.....utility company fixed and problems went away! In spite of good bonds and grounding system unbalanced loads were creating the stray voltages/currents.

 

[kwired]

Echoing earlier posts about problem may be far removed from the hot tub itself....once had a similar issue with a kiddie pool at a Jersey beach club. We had recently performed all the bonding upgrades for pools, spas, etc, and yet some people were feeling "tingles" to step railing at pool. Checked all the bonds, etc......ran some THHN out to the pool area from main EGC and verified all bonds were good....yet still randomly were getting voltage readings from area to the THHN.....started to look for neutral problems....couple hours later noticed possible damage in the overhead utility drop. Turns out the neutral had taken a lightning hit and was mostly severed.....utility company fixed and problems went away! In spite of good bonds and grounding system unbalanced loads were creating the stray voltages/currents.

Not trying to pick on you or anything, but the stray voltages are a result of the voltage rise on the service neutral because of the compromised point in the service drop. And yes it is unbalanced current that will cause more load on the neutral and the more unbalanced the more the load, the more the voltage to earth will rise on this conductor. This is true even if the neutral is in good condition, just not to as much of an extreme that the voltage drop is noticeable most cases.