(B) Wet-Niche Luminaires.
(1) Forming Shells. Forming shells shall be installed for the mounting  of all wet-niche underwater luminaires and shall be equipped with  provisions for conduit entries. Metal parts of the luminaire and forming  shell in contact with the pool water shall be of brass or other  approved corrosion-resistant metal. All forming shells used with  nonmetallic conduit systems, other than those that are part of a listed  low-voltage lighting system not requiring grounding, shall include  provisions for terminating an 8 AWG copper conductor.
(2) Wiring Extending Directly to the Forming Shell. Conduit shall be  installed from the forming shell to a junction box or other enclosure  conforming to the requirements in 680.24. Conduit shall be rigid metal,  intermediate metal, liquidtight flexible nonmetallic, or rigid  nonmetallic.     
(a)     Metal Conduit. Metal conduit shall be approved and shall be of brass or other approved corrosion-resistant metal. 
(b)     Nonmetallic Conduit. Where a nonmetallic conduit is used, an 8  AWG insulated solid or stranded copper bonding jumper shall be installed  in this conduit unless a listed low-voltage lighting system not  requiring grounding is used. The bonding jumper shall be terminated in  the forming shell, junction box or transformer enclosure, or  ground-fault circuit-interrupter enclosure. The termination of the 8 AWG  bonding jumper in the forming shell shall be covered with, or  encapsulated in, a listed potting compound to protect the connection  from the possible deteriorating effect of pool water.