pool bonding and the IRC

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jes25

Senior Member
Location
Midwest
E4104.1 Bonded parts. The following parts shall be bonded together:
1. All metallic parts of pool, spa and hot tub structures, including the reinforcing metal of pool, spa and hot tub shells, coping stones and decks.

I am pretty sure I am reading this right but would like a little reassurance. Basically this section tells me to bond the reinforcing metal of pool structures not the structure itself. Stated another way, if I have a pool structure with a concrete bottom with no steel in it, I don't bond anything.

The point here is to only bond metal? If concrete is conductive, should we not have to bond it someway?
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
I don't have the book in front of me, but I think that a concrete pool without steel would require a made equipotential bonding grid within the concrete.
 

jes25

Senior Member
Location
Midwest
I don't own a 2005 NEc, but I do believe that is required in it. Can you deduce the need for a adding a grid from my quote out of the IRC?
 

rcarroll

Senior Member
1st., I've never seen a pool without rebar all over it. 2nd, if you read 680.26(B)(1) 05 NEC, one sentence will tell you that rebar with insulating nonconductive compound need not be bonded. Next sentence says rebar encapsulated with a non conductive compound needs an alternate means to eliminate voltage gradients.... I'm confused. :? I did not check the IRC. Ron
 

jes25

Senior Member
Location
Midwest
The pools is an inground Vinyl lined. It has a masonry bottom, installed with a trowel . I dont own a 05 NEC because its not adopted here ( we use '02), and for 1 and 2 family dwellings its the IRC.

When I got to the job yesterday this masonry bottom without rebar was in the process of being installed so I can not install a equipotential plane (I do believe it would be the best).

My real question is: Does anyone read the statement from the IRC in my first post to require a equipotential plane. I am looking for an interpertation of the technical language, as English is not my best subject. From the IRC does it require bonding of the pool shell or the metal, that may or may not be in the shell?

Hope I am making sense.
 

raider1

Senior Member
Staff member
Location
Logan, Utah
The way I read section E4104.1 1 is that if you have reinforcing steel it must be bonded or if the reinforcing steel is encapsulated you must provide an alternate means for eliminating voltage gradients, but if no reinforcing steel is there you don't need to install alternate means.

The 2005 NEC has rewritten the section on equipotential bonding grids to add "or another conductive material is not available" to section 680.26(B)(1). This now requires a equipotential bonding grid even if there is no reinforcing steel available.

JMHO Chris
 

jwelectric

Senior Member
Location
North Carolina
jes25 said:
I don't own a 2005 NEc, but I do believe that is required in it. Can you deduce the need for a adding a grid from my quote out of the IRC?

Here is the complete section. Read all of it and see if you find your answer.

E4104.1 Bonded parts. The following parts shall be bonded together:
1. All metallic parts of pool, spa and hot tub structures, including the reinforcing metal of pool, spa and hot tub shells, coping stones, and decks. The usual steel tie wires shall be considered suitable for bonding the rein- forcing steel together, and welding or special clamping shall not be required. Such tie wires shall be made tight. Where reinforcing steel is effectively insulated by a listed 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 volt-age gradients that would otherwise be provided by unencapsulated bonded reinforcing steel.
2. All forming shells and mounting brackets of no-niche luminaires except where a listed low-voltage lighting system is used that does not require bonding.
3. Allmetal fittingswithin or attached to pool, spa and hot tub structures. Isolated parts that are not over 4 inches (102 mm) in any dimension and do not penetrate into the pool structure more than 1 inch (25.4mm) shall not require bonding. The metal bands or hoops used to secure wooden staves for a hot tub or spa shall not be required to be bonded.
4. Metal parts of electrical equipment associated with pool, spa and hot tub water circulating systems, including pump motors and metal parts of equipment associated with pool covers, including electric motors. Metal parts of listed equipment incorporating an approved system of double insulation and providing a means for grounding internal nonaccessible, noncurrent-carrying metal parts shall not be bonded. Where a double-insulated water-pump motor is installed under the provisions of this section, a solid 8 AWG copper conductor that is of sufficient length to make a bonding connection to a replacement motor shall be extended from the bonding grid to an accessible point in the motor vicinity. Where there is no connection between the swimming pool bonding grid and the equipment grounding system for the premises, this bonding conductor shall be connected to the equipment grounding conductor of the motor circuit.
5. Metal-sheathed cables and raceways, metal piping and all fixed metal parts that are within 5 feet (1524 mm) horizontally of the inside walls of the pool, spa or hot tub and that are within 12 feet (3658 mm) above the maximum water level of the pool or any observation stands, towers or platforms, or from any diving structures, and that are not separated from the pool by a permanent barrier.
For pool water heaters rated at more than 50 amperes and having specific instructions regarding bonding and grounding, only those parts designated to bonded shall be bonded and only those parts designated to be grounded shall be grounded

E4104.2 Parts not required to be bonded. Small conductive surfaces not likely to become energized, such as towel bars, mirror frames, and air and water jets and drain fittings that are not connected to metallic piping, and similar equipment installed on or within indoor spas and hot tubs shall not be required to be bonded.

E4104.3Methods of bonding. It shall not be the intent to require that the 8AWGor larger solid copper bonding conductor be extended or attached to any remote panelboard, service equipment, or any electrode, but only that it shall be employed to eliminate voltage gradients in the pool area as prescribed.
Bonding shall be accomplished by one or more of the following methods:
1. Common Bonding Grid. The parts specified in Section E4104.1 above shall be connected to a common bonding grid with a solid copper conductor, insulated, covered, or bare, not smaller than 8 AWG. Connection
shall be made by exothermic welding or by pressure
connectors or clamps that are labeled as being suitable
for the purpose and that are made of stainless steel,
brass, copper or copper alloy.
The common bonding grid shall be permitted to be any of the following:
1.1. The structural reinforcing steel of a concrete pool where the reinforcing rods are bonded together by the usual steel tie wires made up tight or the equivalent; or
1.2. The wall of a bolted or welded metal pool; or
1.3. A solid copper conductor, insulated, covered, or bare, not smaller than 8 AWG.

2. For hot tubs and spas, metal to metal mounting on a common frame or base
3. The interconnection of threaded metal piping and fittings.


My personal opinion is that the IRC should NOT be used to do an electrical inspection. The NEC is hard enough to understand and is not restrictive enough much less a building code trying to replace it,

:)
 

jes25

Senior Member
Location
Midwest
jwelectric said:
My personal opinion is that the IRC should NOT be used to do an electrical inspection. The NEC is hard enough to understand and is not restrictive enough much less a building code trying to replace it,

:)

I agree, the IRC pretty much sucks but I didn't adopt it.

Thanks for posting the whole section. I would have been typing for a week!

-------------------------------------------------------------------------------------
I agree with what raider had posted:

The way I read section E4104.1 1 is that if you have reinforcing steel it must be bonded or if the reinforcing steel is encapsulated you must provide an alternate means for eliminating voltage gradients, but if no reinforcing steel is there you don't need to install alternate means.
------------------------------------------------------------------------------

Any other opinions?
 

jwelectric

Senior Member
Location
North Carolina
jes25 said:
I agree, the IRC pretty much sucks but I didn't adopt it.

Any other opinions?

To install a pool either in ground or above ground using the minimum requirements of the IRC would be installing a potential death trap.

I very highly recommend that an equipotential bonding grid be installed in the concrete of the pool as outlined in 680.26 of the 2005 NEC.

I also recommend that you do every thing in your power and lobby to have the electrical portion of the IRC deleted in your state and the NEC adopted.
:)
 

jes25

Senior Member
Location
Midwest
Even if we were to install an equipotential bonding plane and the underground service phase conductor became damaged causing a voltage gradient ie: current flowing to equipotential bonding plane via damp dirt. Would this not cause a problem the moment a wet person stepped off the plane onto "regular" dirt? Is there not a difference in potential there? Is it not enough to cause harm? Isn't a person standing on a equipotential bonding plane a parallel path in the event there is stray currents in the area? Is this the one time we use the old adage "Electricity takes the path of least resistance" assuming the path of least resisitance is the bonding plane

Other than a insulation failure in an underground feeder, branch circuit or service lateral how can these stray voltages develop? Is small currents flowing from electrode to electrode enough to cause an issue in a pool situation? I bet it would if the service had a bad neutral.

Thanks in advance if anyone trys to answer this. I am sorry if its confusing. I am just trying to get a good grasp on the concept.
 

iwire

Moderator
Staff member
Location
Massachusetts
jes25 said:
I was thinking along the lines of the areas adjacent to the pool.

Like this?

BondingGrid-4.jpg
 

jes25

Senior Member
Location
Midwest
Yeah, What good does it do. If we have a service lateral installed a min. of 5' away with a fault in it wouldn,t there be a potential difference between the "plane" and the surronding dirt. Same goes for faulty neutral etc.

Even if you were standing on the plane wouldn,t you be in parellel with the malfunctioning circuit. I assume its not enough to matter
 

jes25

Senior Member
Location
Midwest
I would like to apologize for some of my post in this thread. I know it was hard to understand. I was typing as I was thinking, and my mind has a tendency to get going a little too fast. :oops:

Let us look at an example as I try to fine tune my understanding of the subject.

You have a pool on a hill. In order to make the pool area level a retaining wall is employed, and the area backfilled level. The retaining wall is of poured concrete with rebar in it. It's construction is similar to a poured basement wall. The top part of the wall is above the level of the pool "deck" area. This wall is not part of the pool construction.

Is this retaining wall required to be bonded if it is over 5' away? What if it is under 5'? If not required do you feel it should be?
 
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