For the first time in the 1962 edition of the National Electrical Code standard and connected to the earth system is explained in the pool. According to this version, all metal objects such as steel rebar in concrete (auxiliary), metal ducts, plumbing, foundation, pool, exterior lights, ladders, diving boards, etc. are connected with each other and the Earth system. So for this connective minimum 14 AWG wire size is considered. In 1965, with incremental changes 8AWG connective wire size is considered. Also in 1968, was due any metal object in the privacy of one and a half meters from the pool with this system has the potential to be.Standard NEC 2011 and the final version (2014) requirements referred very close to the principles contained in the 1962-1968 version, which we hope Tvnyr engineering company bliss collaborate on projects and have provided these details.