Distance from the ground electrode to....?

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06.07.15                           , , , 

One of the most popular questions in the organization of grounding is the question about the distance to the object, which should be followed when installing the ground electrode. Let us study this question with the help of the following regulatory documents:

  • Electrical installations code (EIC);
  • Regulation on the organization of protective grounding and potential equalization in electric installations (R 1.03-08);
  • Guidelines for surge protection of secondary circuits of power stations and substations (AD 34.20.116-93).

1. Distance from the ground electrode to the building base

Distance from the ground electrode to the building base

It is possible to  find the answer to this question in paragraph 1.7.94 of the EIC, which states:

"... laying in the ground at the depth of 1 m and at a distance of 1 m from the building base or from the perimeter of the territory occupied by the equipment, ground electrode system, connected to the potential equalization system of the building or the area, and at the entrances and accesses to the building - laying of conductors at the distance of 1 and 2 m from the ground electrode 1 and 1.5 m deep correspondingly, and connection conductors with the ground electrode system ... "

2. Distance from the grounding to power cables and pipes

Distance from the grounding to power cables and pipes

Excerpt from the Regulation 1.03-08:

Laying ground conductors parallel to cables or pipelines should be performed at the distance of not less than 0.3 meters and at intersections - not less than 0.1 meters. 

This item regulates the distance to the grounding device at the distance to the lightning rod / down conductor more than 10 meters (horizontally).

3. Another document - AD 34.20.116-93 places demands to the distance from different objects to the ground electrode with the connected lightning protection:

Cable routing with circuits of control, measurements and alarm systems should be laid at the distance of not less than 10 meters in the light from the base of foundations (racks) with arresters and lightning rods. It is allowed to reduce the distance to 5 m in confined nature, but an additional longitudinal ground conductor not less than 15 meters at the distance of 0.5 meters from the cable routing should be laid between the foundation (rack) and the cables. This longitudinal ground electrode should be located symmetrically with respect to the foundation (the rack) and connected to the grounding device at the ends and at the points of intersection with other horizontal ground electrodes.

Design and calculate grounding and lightning protection correctly! 

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