All controller equipment and associated external fuse or disconnect devices for traffic signals, flashing or iluminated signs shall be installed so as to (1) insure that an electrical connection exists between the service neutral conductor, the metallic controller enclosure, any metallic external fuse or disconnect device enclosure and the metallic conduit and (2) preclude the possibility of reversing the phase and neutral connections.
Conn. Agencies Regs. § 16-243-3