how to calculate no. of earthing pits and their diamensions?
no. of lightning arrester rods which are required to
protect a building of 35 mtr and we calculate?
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Answer Posted / william lobo
The number of earthing pits depends on the soil resistance.
We may require earth resistance of 1ohm or 3 ohms at the
most. To get this we will have to install at least 2 pits
and as per parallel formula i.e. 1/r1+1/r2+1/r3= 1/R. We
have to keep on increasing the number of earth pits till we
get the required value for R=1 or 3 as per requirement.
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