Protective Bonding Circuit : The whole of the protective conductors and conductive parts used for protection against electric shock in the event of an insulation failure
NFPA 79 Electrical Standard for Industrial Machinery, 2002 ed. http://www.nfpa.org/assets/files/AboutTheCodes/79/ 79-A2002-rop.pdf, (Electr Std for Ind Machinery - Amer) {225 NFC}