pool voltage need help

[starbolin]

bonding (where several gnd rods are on same bonding) should be a good thing, no?

Unlikely to make any difference or only to reduce potentials in a small area. All you really end up doing is pushing the problem around. Could cause 'objectionable currents'.

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do pools ever develop static charge??
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Can't say never but concrete is a pretty good conductor so the pool shell is usually at local earth. The problem is local earth not being the same the POCO neutral.

 

[hurk27]

sorry, i also meant to add, bonding with gnd rods where the whole thing is tied to service gnd (aka "earth gnd"). does this mess with ability of gfci to function properly?

As said previously and in many other recent threads like post 16, ground rods do not have a low enough impedance path to lower the voltage to a safe level, with the 3 volt example in this thread a 25 ohm ground rod electrode would only apply a 120ma current load to this 3 volts that may have 5 to 10 amps of current behind it, using multiple rods do not add much more resistance to load it down either, to drop the 3 volts to 1 volt would require a resistance of the electrode system of .4 ohms @ 5 amps of supply current, I don't think you are going to reach that even with a CEE, or even a #12 ran to the X0 of the transformer, it's not going to happen.

As far as a GFCI goes, a GFCI does not monitor any grounding conductors, the voltage on the EGC's are of no concern to a GFCI, even if the GFCI trips the voltage will be still there as they do not remove the EGC connection, a GFCI measure's the current between the hot and the neutral if they are the same then there is no fault it doesn't trip, if the hot has .005 amps more then the neutral it trips, it does this by passing both the hot and neutral conductors through a current transformer, this is called zero sequencing, if the current in both are equal then the current flowing to the load cancels out the current returning from the load because it is 180? out of phase with the other, this canceling effect stops proportionally when the currents are no longer balanced, and when they do a voltage is developed in this current transformer which is tied to the electronics in the gfci which tells it to trip, but again a GFCI will not provide protection for a raised voltage on the grounding as it will not sense it or will it disconnect it.

 

[don_resqcapt19]

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the issue i see with just bonding is that leaves possibility that the voltage on such bonding can be bridged by wet feet between bonded item and some other lower potential item (earth, other, etc)....

Exactly why the code requires pool deck bonding. The real problem is when you are in the water and touching something that is not bonded. After you are out of the water the low voltage between something that is bonded and something that is not, is not much of a problem.

do pools ever develop static charge??

In general a resistance of 1,000,000 ohms or less between the two objects will will prevent the build up of static charge.