Electrical Shock

[tenax]

and that's why i'm hiring an electrician..i've done the new wiring for a basement myself and it worked out well..but i'm not playing with water, electricity and breakers!

[JohnT]

But you absolutely.....no way around it.......need a good earth ground! That means 1-3 8' copper stakes in the ground and tied securely to your pool ground lugs and equipment lugs.

I'm an EE as well, and you absolutely do not need an earth ground on a pool system. 2005 NEC had a footnote added to clarify this. The addition of a ground rod can cause stray voltage issues under certain circumstances.

The lugs on the pool and equipment aren't called ground lugs, they are called bonding lugs, and they are used to create an "equipotential plane" which prevents anyone in the pool from coming into contact with any two things that are at significantly different voltages. Ground doesn't enter the equation until the bonding wire is connected to the bonding lug on the pump motor housing, which is grounded via the service lead to the house's service panel ground. Look at NEC 2005 680.26.

[South_Texas_Sun]

I'm an EE as well, and you absolutely do not need an earth ground on a pool system. 2005 NEC had a footnote added to clarify this. The addition of a ground rod can cause stray voltage issues under certain circumstances.

The lugs on the pool and equipment aren't called ground lugs, they are called bonding lugs, and they are used to create an "equipotential plane" which prevents anyone in the pool from coming into contact with any two things that are at significantly different voltages. Ground doesn't enter the equation until the bonding wire is connected to the bonding lug on the pump motor housing, which is grounded via the service lead to the house's service panel ground. Look at NEC 2005 680.26.

No offense, but this is what I mean by bad internet information. The NEC revision IS AN EARTH GROUND, but in grid form for pools that have conductive construction elements that can be separate from a central earth ground, but connected to improperly grounded equipment.

This won't exactly work for someone who's already built the pool! ....lol

Bottom line: Use proper EARTH grounding or get a group funeral plan.

Here's the section:

1. Revise 680.26 (C) & 680.26 (C)(1) as follows:

C) Equipotential Bonding Grid. The parts specified in 680.26(B) shall be connected to an equipotential bonding grid with a
solid copper conductor, insulated, covered, or bare, not smaller than 8 AWG or rigid metal conduit of brass or other identified
corrosion-resistant metal conduit. Connection shall be made by exothermic welding or by listed pressure connectors or clamps
that are labeled as being suitable for the purpose and are of stainless steel, brass, copper, or copper alloy. The equipotential
bonding grid shall conform to the contours of the pool and shall extend within or under paved walking surfaces for 1 m (3 ft)
horizontally beyond the inside walls of the pool and shall be permitted to be any of the following:
Exception: The equipotential bonding grid shall not be required to be installed under the bottom of or vertically along the walls of
vinyl lined polymer wall, fiberglass composite, or other pools constructed of nonconductive materials. Any metal parts of the
pool, including metal structural supports, shall be bonded in accordance with 680.26(B). For the purposes of this section, poured
concrete, pneumatically applied (sprayed) concrete, and concrete block, with painted or plastered coatings, shall be considered
conductive material.
(1) Structural Reinforcing Steel. The structural reinforcing steel of a concrete pool or deck where the reinforcing rods are bonded
together by the usual steel tie wires or the equivalent. Where deck reinforcing steel is not an integral part of the pool, the deck
reinforcing steel shall be bonded to other parts of the bonding grid using a minimum 8 AWG solid copper conductor. Connection
shall be per 680.26(D).

[Poconos]

Say What? Since when are concrete, paint, and the others considered conductive? Too many variables to make that statement in my opinion but being just a dumb EE I would like to hear some details and an explanation.
Al

Quote from post above.

"For the purposes of this section, poured concrete, pneumatically applied (sprayed) concrete, and concrete block, with painted or plastered coatings, shall be considered conductive material."

[JohnT]

Where does that say to ground anything? The FPN clearly states that no ground electrode is required, and the word ground does not appear in the quoted text.

680.26a Fpn: The 8 Awg Or Larger Solid Copper Bonding Conductor Shall Not Be Required To Be Extended Or Attached To Any Remote Panelboard, Service Equipment, Or Any Electrode.

There is no requirement in the 2005 NEC for grounding anything to do with a pool except as is normal for all electrical wiring. 680.26 establishes the requirement for an equipotential bonding grid, not a ground system. Although the FPN is not enforceable, it indicates the intent of the code, and a proposal changing that text from an FPN to part of the code has been accepted by the TCC for inclusion in the 2008 NEC (proposal 17-114a), while a numerous proposals (most if not all by the same person) requiring the bond wire be connected to a ground rod have been rejected (17-116).

[JohnT]

Say What? Since when are concrete, paint, and the others considered conductive? Too many variables to make that statement in my opinion but being just a dumb EE I would like to hear some details and an explanation.
Al

It is because of "water intrusion", e.g. wet concrete is conductive. The rest of the statement just refers to the method of concrete application.

[mas985]

Sorry to butt in on this one, but having a masters degree in EE myself, last time I checked it did not qualify me to be an electrician. Having said that, it does help to understand electrical theory and with a bit of experience you can do most of what an electrician does. I just don't see the relevance on pointing out you are an EE. In fact, I think I learned more about house wiring and grounding in my shop class in high school.

Also, forgive my arrogance STS but how does one become an EE through just training and not a degree? Technician yes, engineer, I am not so sure.

Now back to the topic. Hsdancer, you mentioned that when you reach out from the pool and step on the pavers you get the shock. Does that mean you are also holding on to a railing? If so, it could mean the railing is not bonded as well. Was it added later?

Regardless of what the code says or does not say, it probably would not hurt anything to try an extra grounding rod near the pad. If it does solve your problem, then the problem is probably with the grounding in the house or power company.

Also, turning off the power in your house does not change the grounding or neutral only shuts off the hot leads so you may not detect it doing this.

[DONNIE]

Don't mean to jump in the middle of your conversation but it sounds like you guys can answer a simple question. I am planning on adding a wood deck, outward from the concrete around my pool. Do I need to ground the deck in any way? Posts will be poured in concrete. Deck may or may not attach to the concrete around the pool.

Donnie

[South_Texas_Sun]

That's NEC text Al. I didn't write it. But if you stand on wet concrete in bare feet, and grab a leg of 220, don't say they didn't warn you!......lol

EVERY material, including your body, pool water, even the air you breath is conductive. Some are more resistive than others, but when you BURY a metal mesh, you have an EARTH GROUND whether you know it or not. (And you EE's should certainly know that!)

ANY resistive element will create a voltage drop across it's length when connected to a source e, so relying on a utility co. "service ground", depends on the conductivity/current carrying capacity of the wire and the connection quality of EVERY TERMINAL in between you and the generator. Lose connection quality at ANY POINT and you've created a voltage drop across that point and in series with the load. And bingo, you've got yourself a ground loop. (just remember, on the murphy side of the equation, we're talking about little people standing in pools of ionized water and carrying long metal poles around)

I'm not here to make enemies, but to learn about pools and make a few friendly acquaintances. I'm not going to take the other side of posturing that will put someone's family in jeopardy, so this'll be my last post on the topic.

I stand behind everything I've written and practice what I preach My family is too important to me, not to take the best precautions.

STS

[South_Texas_Sun]

Sorry to butt in on this one, but having a masters degree in EE myself, last time I checked it did not qualify me to be an electrician. Having said that, it does help to understand electrical theory and with a bit of experience you can do most of what an electrician does. I just don't see the relevance on pointing out you are an EE. In fact, I think I learned more about house wiring and grounding in my shop class in high school.

Also, forgive my arrogance STS but how does one become an EE through just training and not a degree? Technician yes, engineer, I am not so sure.

Now back to the topic. Hsdancer, you mentioned that when you reach out from the pool and step on the pavers you get the shock. Does that mean you are also holding on to a railing? If so, it could mean the railing is not bonded as well. Was it added later?

Regardless of what the code says or does not say, it probably would not hurt anything to try an extra grounding rod near the pad. If it does solve your problem, then the problem is probably with the grounding in the house or power company.

Also, turning off the power in your house does not change the grounding or neutral only shuts off the hot leads so you may not detect it doing this.

Devry Institute of Technology BSEE