User's Manual

MicroMAX Hardware Installation User Guide
Page 80 Commercial in Confidence UWB-D00068 Rev J
Figure 71 - Air Terminal
Figure 72 - Termination and Tower
17.1.2 Grounding
Low-resistance grounding provides an efficient destination for the "lightning." If the site soils are
composed of sand or rock, they are resistive, not conductive. If the surrounding soils are clays or
dirt with moisture present, they likely are conductive. "Good Grounds" are achieved by volumetric
efficiencies. We recommend buried bare 4/0 copper wire – the so-called ring electrode or ring.
The grounding of the Down Conductor to earth must be of ground resistance no higher than 5 Ω.
This is achieved by using Earth Terminations and wherever possible, grounding to the steel re-
enforcement bars of the concrete base of the tower. This constitutes a part of the safety network
adapted to the electricity laws of the country, the terrain conditions, and the accepted and relevant
standards for the country.