Bonding Pool Water
Pool Design article by Paolo Benedetti, SWD Master
The National Electric Code requires that the water in a vessel be bonded. Historically, this was a no brainer since most pools had stainless steel light niches, hand railings and light fixtures.
With the advent of fiber optic and LED lighting, plastic hand railings and no-niche lights, the water bonding isn’t always so obvious.
NEC [680.26(C)] requires that there be at least 9 square inches of non-corrosive metal in contact with the water. This can be a bronze umbrella sleeve, plastic light niche (they have over 9 square inches of stainless steel in them), or special bonding device. If you have a heater on a simple pool, the water is bonded.
Think through your placement of the water bonding. However, if the project is a pool and spa combination, then each vessel will not always be bonded. When the valves isolate the vessels, one vessel water will lose it’s bonding. So even with a heater on a pool and spa combination, redundant bonding will be required on each vessel.
To properly bond the water in a pool and spa combination project will require two devices, one in each return line after the isolation valves. This way the water in each vessel remains bonded 24/7, regardless of valve positions.
Paolo Benedetti, SWD Master
Aquatic Technology Pool & Spa
PO Box 130
Morgan Hill, CA 95023
T (408) 776-8220