Grounding grids design

This is the parameter that will help to decide the size and type of the grounding grid and design of the mesh. 

Estimating the value of ground conductor length to design the grounding grid... 

There are, of course, many cities approximating Descartes s model. For obvious reasons, most have been planned from the ground up as new, often utopian cities. Where they have not been built by imperial decrees, they have been designed by their founding fathers to accommodate more repetitive and uniform squares for future settlement. A bird s-eye view of central Chicago in the late nineteenth century (William Penn s Philadelphia or New Haven would do equally well) serves as an example of the grid city (figure 9). 

Table H.lc. Data for earth resistance, touch voltage, ground potential rise and corner mesh voltage for different grid and rod designs...

Until the early 1990s, nearly all products were laid out in what is now referred to as the conventional layout. In this layout, which is still used for most products, individual test plots (ground boards and concrete slabs) are separated in a grid on 1.5-m centers. Each of ten replications contains a mixture of rates, products, test methods and control plots arranged in a randomized block design (Figure 4). Replications are laid out in two tiers of five replications per tier. The conventional layout utilizes about 0.08 ha. 

Figure 6.32 Sketches of (a) an ultra-simple iinear time of flight anaiyzer and (b) a modern design with two extraction grids (permitting the space focus point to be moved to a reasonabiy iarge distance Xjf) and a reflectron (the grids are at increasing electrical potentials from the first entrance grid that is at ground), see main text. Not drawn to scale (in particular the angle y should be small l-2°).

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