Introduction

Pool water bond fittings play a crucial role in ensuring the safety and compliance of swimming pools. These fittings are designed to bond the water in the pool to the surrounding equipment, thereby preventing electrical hazards. This article delves into the importance of pool water bond fittings, when they are required, where they are mentioned in the National Electrical Code (NEC), and how to properly test them.

When we perform pool inspections, this is sometimes an issue that we note, based on our other observations.

NEC 2023 References to Pool Water Bond Fittings

The National Electrical Code (NEC) provides detailed guidelines on the installation and maintenance of pool water bond fittings. Understanding these references is vital for ensuring compliance and safety.

NEC Article 680

NEC Article 680 specifically addresses the requirements for swimming pools, fountains, and similar installations. This article outlines the necessity of bonding and grounding to prevent electrical hazards.

Section 680.26 – Equipotential Bonding

Section 680.26 of NEC Article 680 focuses on equipotential bonding, which is crucial for preventing voltage differences between conductive parts and the pool water. This section mandates the bonding of all metallic parts, including pool water, to maintain a consistent electrical potential.  Mentioned in 680.26(C) is the requirement to install a water bond.

680.26(C) states that when none of the bonded structures mentioned in 680.26(B)(1) through 680.26(B)(7) you need an additional water bond fitting that has at least 9 sq. in. (5800 square millimeters) of surface area in contact with the water. It must be protected from physical damage that could happen from normal pool use, and it must be corrosion-resistant. The water bond must be connected to the grounding system for the pool.

When are Pool Water Bond Fittings Required?

Pool water bond fittings are essential in maintaining the safety and integrity of a swimming pool’s electrical system. They are required in various scenarios, including:

1. When the bonding system is not in place or is improper. If your bonding system has issues or appears to be incorrectly built, you need to install a pool water bond to ensure proper contact between the ground system and the pool’s water.
2. When you have an unknown paint material coating the inside of the pool. Sometimes paints and coatings can create a barrier where ions in the water are unable to pass, and so block the transfer of electrical power. Communication with the original pool designer or constructor is necessary to investigate this issue.  The NEC tells us that the shell itself is conductive if made of concrete, but not that it is considered conductive to the pool water. Most concrete is highly conductive, unless dry or painted with an unknown insulating material.
3. When the original pool designer/constructor cannot be contacted. If you cannot confirm the design, methods, and materials with the original pool designer, the installation of a water bond fitting can be required to ensure good electrical contact.  One question that often needs answering is did you coat the reinforcing steel, and what coatings were used on the pool’s internal shell.  Additionally, a surrounding copper grid may be required per NEC 680.26(B)(1), where if reinforcing steel is coated (or the status is unknown), you must install a copper grid instead of a copper loop to reduce voltage gradients surrounding the pool.  This extra copper at the surface makes up for the pool shell having poor electrical contact with its surrounding soil, when the rebar has been coated.  
4. When it will take time to test and approve the existing bonding method. If your bonding system is in disrepair or has construction defects, you may be required to install a water bond as an emergency safety measure as you fill the pool. The water bond fitting is inexpensive and simple to install, making it a good option for quickly achieving a safe installation.
5. When the construction of the pool had multiple other issues. Multiple issues with a pool can create situations where inspectors and engineers may become worried about hidden issues. To mitigate the unknown, additional safety measures like a pool water bond may be required by the inspectors and engineers to ensure public safety.
6. When repairs will take longer than filling the pool. If you are filling the pool to prevent damage from heaving and need more time to correct other grounding issues, installing a water bond can ensure proper electrical contact.
7. Multiple safety issues and missed inspections.  If you have multiple problems with a pool, and the original pool shell was also not inspected, this can yield the requirement to attach a pool water bond fitting. This is to ensure that any hidden & untestable discontinuities or breaks in the grounding system won’t affect its safety performance.
8. When the pool design calls for one. If your pool’s design documents require a water bond fitting, it must be installed.
9. When the lights cannot be properly inspected. When you cannot inspect the lighting fixtures, a water bond fitting may be required to ensure safety.
10. When the inspector or engineer requires one. If the inspector, electrician or engineer needs to see a water bond in order to achieve protection of the public, then it is required that one be installed.

Where to install the water bond?

The manufacturer will give precise instructions on where to place their fitting.  In general, you want it below the water level of the pool so that it is always in contact with water. Water bond fittings can be installed in a ground box for easy access and replacement.

Proper Testing of Pool Water Bond Fittings

Testing pool water bond fittings is essential to verify their functionality and ensure safety. The following steps outline the proper procedure for testing these fittings:

Visual Inspection

The first step in testing pool water bond fittings is a thorough visual inspection. Check for any visible signs of wear, corrosion, or damage to the fittings and bonding wires. Ensure that all connections are secure and free from debris.

Continuity Testing

Continuity testing involves using a multimeter to check for electrical continuity between the pool water and the bonded equipment. Follow these steps for accurate testing:

• Turn off all power supply to the pool equipment.
• Set the ground meter to the 2-pole AC resistance mode.
• Place one probe of the multimeter in the pool water and the other probe on the bonded equipment (e.g., pump, heater, or light).  In the pool water, the use of a clean ground spike can assist in getting good electrical contact.  It is important to note, that getting good contact when taking this measurement may in fact produce a result that is not conservative or even realistic.  Consider how much surface area will be exposed by a dropped cable during this phase.  Careful application of engineering judgement may be required here. We recommend the installation of a water bond if there is any lingering doubt at all about the pool’s safety.
• Check the multimeter reading. A low resistance reading indicates good continuity and proper bonding. A high resistance or no reading suggests a problem with the bonding connection.

Voltage Testing

Voltage testing helps in identifying any stray voltage in the pool water, if the pool is full. Follow these steps to conduct voltage testing:

• Turn on the power supply to the pool equipment.
• Set the multimeter to the voltage mode.
• Place one probe of the multimeter in the pool water and the other probe on a known ground point (e.g., metal fence or ground rod).
• Check the multimeter reading. A significant voltage reading indicates the presence of stray voltage, which needs to be addressed immediately.

Professional Assessment

While the above steps provide a basic guideline for testing pool water bond fittings, it is always necessary to seek a professional assessment from a licensed engineer. They have the expertise and tools to conduct comprehensive testing and ensure compliance with safety standards.

Conclusion

Pool water bond fittings are integral to the safety and compliance of swimming pools. They ensure that the pool water is electrically bonded to the surrounding equipment, preventing electrical hazards. Understanding when these fittings are required, where they are mentioned in the NEC, and how to properly test them is crucial for maintaining a safe and compliant pool environment. Always prioritize safety and consult with professionals to ensure the proper installation and maintenance of pool water bond fittings.  Dreiym Engineering has performed dozens of inspections of pool grounding and electrical systems.  Contact us today to discuss how we can assist you.