Bonding Pool Water 680.26C
17-99 Log #1190 NEC-P17
(680.26(C) (New)
Final Action: Accept
Submitter: Neil F. LaBrake, Jr. , National Grid Rep. Edison Electric Insitute-Electric Light & Power Group
Comment on Proposal No: 17- 122
Recommendation: Accept Proposal 17- 122.
Substantiation: Testing done by a National Laboratory (NEETRAC) clearly substantiates that the potential for shock hazard is present in pools where the pool water is not bonded via metal parts in the pool. With this knowledge and confirmation of a potential shock hazard , CMP- 17 must address the issue. NEETRAC, in its proposal , recommended a
solution for bonding pool water. The proposed solution was tested and worked successfully. While the proposed solution may not be the only solution , it meets the NEC criteria of providing minimum protection for the public.
Panel Meeting Action: Accep 17-98 Log #802 NEC-P17
(680.26(C) (New)
Final Action: Accept
Submitter: Frank C. Lambert, Georgia TechlNEETRAC
Comment on Proposal No: 17- 122
Recommendation: Proposal 17- 122 should have been adopted in its entirety.
Substantiation: Extensive testing clearly substantiates that the potential for voltage gradient is present in pools where the pool water is not bonded via metal parts in the pool. With this knowledge and confirmation of a voltage gradient hazard , the CMP must address the issue. Test results, handed out at the Proposal Meeting, show that the presence of a touch potential exists in all areas of the pool and that the proposed solution for bonding pool water will essentially reduce that potential to zero. While the proposed solution may not be the only solution , it meets the NEC criteria of providing minimum protection for the public. The test report in its entirety has been submitted to this Comment for further review by the Panel Members.
Typically, pool water is considered electrically conductive due to dissolved chemicals. Although the conductivity will vary with the temperature, the change in conductivity for all practical purposes is not a factor in the application of a proposed solution. Again, the proposed solution meets the NEC criteria of providing minimum protection for the public
and should be viewed as a protection measure compared to having no protection.
In the proposed solution , the size of bonding conductor is not specified. This is in line with several Bonded Parts described in 680.26(B). In 680.26(B)(1), (B)(2), (B)(3), and (B)(5), use of a minimum of #8 AWG size wire is implied as specified in 680.26(B)(4) and 680.26(C). In the stray voltage field, ground currents are rarely determined due to measurement difficulties and inaccuracies. On the other hand , resulting voltage gradients (stray voltages), however, are very easy to measure and can be directly used to analyze stray voltage problems and their mitigation. As evidenced by the test report, the proposed solution is based on such stray voltage measurements around a swimming pool. Note: Supporting material is available for review at NFPA Headquarters.
Panel Meeting Action: Accept