The National Electrical Code (NEC) first introduced swimming pool earthing and bonding in the 1962 edition. In this edition, the code required that all metal objects, including: the steel rebar in concrete (support), metallic conduit, piping systems, pool reinforcing steel, light fixtures, ladders, diving boards and the like, shall be bonded together and earthed to a common earth. A minimum 14 AWG wire was required for this bonding.
In the 1965 they increased the bonding wire size from 14 AWG to 8 AWG, and in 1968 they added the 5-ft rule. The 5-ft rule required that every metal object within 5-ft of the pool must be bonded to the same equipotential earthing system.
Today’s 2011 (and the upcoming 2014) code is very similar to the original 1962-1968 codes, of course with more details and clarifications.
The Engineering Team at E&S Earthing Solutions
Photo Credit: E&S Earthing Solutions