May I ask which specification outlines the requirements for the grounding wire grid?
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This post was last edited by Yu Qin on 2020-5-30 at 17:25. I’ve seen construction drawings of large factory building portal frames created by others, in which the grounding wires (not the lightning arresters) are also arranged in a grid pattern, such as 10×10m. Is there any other purpose to doing this besides preventing step voltage? Which specification requires it. \"Lightning Protection\" GB50057-2010, 4.5.6 2 The protection against step voltage shall comply with one of the following requirements: 1) Utilize the building’s metal framework and the rebar that connects various parts of the building; these elements should be electrically connected together, and a natural down conductor consisting of no less than 10 columns shall be used. The columns that form this natural down conductor include those located around the building as well as those inside it. 2) The resistivity of the surface layer within 3m of the down conductor shall be not less than 50 kΩ·m, or a 5 cm thick asphalt layer or a 15 cm thick gravel layer shall be laid. 3) Use a mesh grounding system to equalize the potential of the ground surface. 4) Use guardrails and warning signs to minimize the possibility of people entering the area within 3 meters of the down conductor. As for this point, I think it’s best to implement it first in large factories; there’s no need to go through the third step.
The grounding is designed in a grid format primarily to limit step voltage differences and contact voltage differences; you can refer to GB/T 50065 for more details
According to the specifications, it is sufficient to meet one of these four conditions; generally, in large factory buildings with more than 10 structural columns, using the rebar within those columns as down conductors will suffice