Retractable Ground Reel

The Retractable Grounding Reel is self-retracting conductor and provides a direct electrical connection between the tank shell and tank floating roof.  It is used for conduction of the intermediate and log duration component of lightening-stroke current. According to API RP 545, the tank floating roof shall be bonded to the tank shell by direct electrical connection

through an appropriate number of bypass conductors. Each conductor, including connections, shall have a maximum end-to- end electrical resistance of 0.03 ῼ . The bypass conductors shall be of the minimum length necessary to permit full move- ment of the floating roof. Bypass conductors should be evenly spaced not more than every 30 m (100 ft) around the tank cir-cumference with a minimum of two.