This diagram really explains the complexity of a swimming pool/spa light installation and why it requires a qualified electrician to perform the entire installation from start to finish. What most pool owners do not know is that the conduit that holds the cord for the light is filled with water for the life of the pool. This is why the junction box in the diagram, is so high off of the ground instead of being hidden underground to hide it. The junction box must be at least 4 ft above the pool/spa water level as the water fluctuates inside the conduit when the pool is in use. The light and shell that holds the light (niche) must be grounded with a bare copper #8 size wire that protects anyone in the pool against fault currents of any kind. This is the kind of installations we perform every day of the week for the past 44 years.
