We are having yet another NEC disagreement in the City of Tampa. I say 680.10 and Table 680.10 are depths for conduits containing wiring not associated with the pool.
I first base my opinion on the Handbook statement; “This section allows wiring within 5 ft of the inside walls of the swimming pool under two conditions. The first condition permits wiring to pool-associated equipment such as an underwater luminaire. The second condition permits wiring not associated with the pool within this area where spatial (space) constraints such as property lines preclude the 5-ft minimum separation. Under the second condition, underground wiring located within the 5-ft zone is required to be installed in rigid metal conduit, intermediate metal conduit, or rigid nonmetallic conduit and must be buried to a depth not less than that required by Table 680.10 for these permitted wiring methods. The raceway must be installed as a complete system between points of termination and cannot simply be a sleeve through the 5-ft zone. Beyond the 5-ft zone, the minimum cover requirements of Table 300.5 apply to the underground wiring methods used for circuits rated 600 volts and less.”
The commentary specifically says the “under the second condition”, wiring not associated must be buried not less than that required by Table 680.10, pretty cut and dry to me.
The Handbook further states; “As indicated by the title of this section (Underground Wiring Location), the focus of 680.10 is to mitigate shock hazards that may occur as a result of a faulty or damaged underground installation that is in close proximity to the swimming pool. Due to water splashing out of the pool and water dripping off those who have been in the pool, the area within 5 ft of the inside walls is generally the wettest location; as a result, electrical leakage from underground installations presents a greater shock hazard in this continuously wet environment.”
So is not the interior of the PVC raceway from the pool niche also a continuously wet environment?
We install the equipotential bond ring between 18” and 24” from waters edge, would not this #8 equipotential ring dissipate any stray voltage from the underground wiring, especially the 15 volt pool light supply?

Please let me know how you all are looking at the requirements in 680.10.

Thank you,
Neal Burdick
City of Tampa Construction Inspector II

One big difference is the circuit feeding the underwater light needs to be GFCI protected. That is not necessarily true of any other system piped through the area that is not part of the pool.

What this is really saying is you can't run that UF circuit, going out in the yard, within 5' of the pool. Makes good sense to me.

Neil ; I do agree, except with the last statement about the ground ring, not especially the pool light, but including the pool light

The burial depth of the underwater light conduit is not really relevant to stray voltage in the ground. It is flooded with pool water up to the water line. That is why we have to mount the J box up in the air. Any leakage is supposed to trip the GFCI

I do not beleive that a 15 volt pool luminaire is required to be GFCI protected.
A pool luminaire over 15 volts and less than 150 volts is only required to be GFCI protected for re-lamping see 680.23(B), but everyone uses GFCI protection on anything higher than 15 volts.
I agree the conduit if always full of water, but the bond ring is there to dissipate any and all stray voltages and or currents that maybe present.

IMHO
Neal Burdick

Neal,

Please see my email response to you regarding the equipotentail bonding system.

We all need to be clear on its purpose...

Bryan,
I agree with you that the bond ring establishes an equal potential plane, but I feel it provides more protection than we realize.
From the 2008 Handbook.
"It is important to understand the difference between the terms bonding and grounding as they apply to Article 680. As defined in Article 100, bonding is “connected to establish electrical continuity and conductivity.” As described in 680.26(A), the function of equipotential bonding differs from the primary function of bonding to meet the requirements of Article 250 in that providing a path for ground-fault current is not the function of the equipotential bonding grid and associated bonding conductors.(we agree it does not provide a "ground fault" path)
The primary purpose of bonding in and around swimming pools is to ensure that voltage gradients in the pool area are not present. (what happens if there are voltage gradients present?)Section 680.26(B) specifies that the 8 AWG conductor's only function is equipotential bonding to eliminate the voltage gradient (to eliminate a voltage gradient does not a voltage gradient of some degree need to be present?)in the pool area and the bonding conductor is not required to extend or connect to any parts or equipment other than those covered in 680.26(B)(1) through (B)(7) and to a pool water bonding element covered in 680.26(C)(this is why I feel it would dissipate a voltage gradient or stray current, maybe not eliminate them completely or cause an overcurrent device to trip, but still would reduce the gradient).
The reason for electrically connecting all of the metal parts described in 680.26(B)(1) through (7) is to ensure that they all are at the same electrical potential. This bonding reduces possible injurious or disabling shock hazards created by stray currents in the ground or piping connected to the swimming pool. Stray currents can also exist in nonmetallic piping because of the low resistivity of chlorinated water." (the bond ring reduces shock possibility created by stray currents, how? I say by dissipation thru a lower resistant path).

IMHO
Neal Burdick
City of Tampa
Construction Inspector II

No, you're still a little off.

The voltage gradients are created by the pool, not by a remote voltage source.

For example, if you install an aluminum frame pool cage on the concrete pool deck that is within 5' of the pool water it needs to be bonded. WHY? Not because it may become energized by stray voltage from an electrical circuit, but due to the fact that a difference in potential can be present between the water and the pool cage. The bonding shorts out this potential.

Stray voltages from a remote source can and will energize the bonded pool parts. The equipotential bonding grid doesn't and can't mitigate that. All the parts bonded together will be energized to that potential until that source is disconnected or the reason for the stray currents is corrected.

Like I stated in my email, think of the pool and its parts like a big battery. All the exposed metal parts that can be touched are like the two electrodes. A voltage potential will be present between these metal parts. A human becomes the circuit connecting the battery, allowing current to flow. Like with a battery, the votlage comes from the battery not from a remote source.

I will be presenting a grounding and bonding class at the July ECF meeting in Tampa. This will not be your typical code based grounding and bonding class.

In this class, I will:

Explain the 3 types of bonding described in the NEC and how they are 3 completely different concepts totaly unrelated.

Explain the 2 ways the term grounding is used in the code that are 2 completely different concpets totaly unrelated.

And most importanly, explain the WHY grounding, bonding, and equipotential bonding is performed.

Yes I am a little off. LOL
I am looking forward to attending your class in July.
Wes says it is very educational, so for now we can agree to disagree.

Neal

Just think of a bird on a wire.