Common use of External Ground System Clause in Contracts

External Ground System. The external ground system for all shelters consists of ground rods placed at each corner of the shelter and 10' intervals along the ground ring, below the waveguide entry, and at the AC service entrance. The rods should be exothermically welded to a perimeter ground ring of #2 AWG solid tinned copper wire. (Tinned copper is recommended to reduce corrosion of the wire). The wire should be buried below the frost line (minimum 30", deep per NEC Sec 250-8(d)), and at least 24", away (measured horizontally) from the foundation. The ground ring should be bonded to the tower ground system at two locations, to the externally mounted ground bars under the waveguide ports and to the AC service ground as close as possible to the service entrance.