Ø  Ground rods 2.4 meter minimum length.
Ø  Cathode protection material is used galvanized steel.
Ø  Individual Ground rod maximum resistance should be 2.5 Ohm.
Ø  For copper or copper jacketed steel rods is a minimum of 16 mm2 in diameter or 19 mm2 in diameters.
Ø  Earth Tester is used for measuring of earthling system.
Ø  Underground wire for grounding to wire connections shall be cadweld or thermoweld. Compression connector shall not be used.
Ø  Shields wires shall be grounded only at the one point for the signal cables.
Ø  Shields and armor of power cables shall be grounded at both ends.
Ø  If used for connections of equipment to ground rods or ground grid be minimum 25 mm2 (# 4 AWG).
Ø  Metallic cable trays shall be bonded at both end points and a minimum of every 25 Meter to the local ground grid.
Ø  If buried / used for grids or interconnections of ground rods to be minimum 70 mm2 (2/0AWG).
Ø  Be copper or copper jacketed steel or galvanized steel or copper jacketed steel shall meet the requirements of UL 476 (Underwriters Laboratories).
Ø  Power Applications:     Metal cable trays must be grounded and eclectically continuous systems as per NEC article 318.
Also Read:  Electrical and Instrumentation NCRs on Projects

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