Appendix № 3 to "Economic justification of using ZANDZ modular grounding".
The activities were carried out in accordance with the EIC 7 th ed. Chapter 1.7
The object of the protective grounding installation a unit transformer substation (UTS) with the voltage of 10/0,4 kW. According to the customer's data, the ground in the intended place of grounding devices installation is clay loam. Specific soil resistance is taken equal to 100 Ohm ∙ m.
In accordance with the
In accordance with EIC 1.7.101
The set of measures to ensure the necessary requirements to the grounding device is represented by the following solutions:
- installation of two vertical electrodes 10.5 m long and one vertical electrode 9 m long of steel copper-bonded rods with the diameter of 14 mm, united by a horizontal ground electrode of stainless steel copper-plated corrosion-resistant tape with the cross-section of 4x30 mm, laid around the UTS. Depth of the tape burial 0.5 m;
- a horizontal ground electrode 1 meter long is laid to the wall of the UTS (copper-bonded tape with cross-section of 4x30 mm).
Arrangement of elements of the grounding device is shown on Figure 1.
Figure 1 - grounding device elements layout
Условные обозначения – code designations
Вертикальный электрод длиной – vertical electrode 10,5 m long
Горизонтальный электрод – horizontal electrode
Зажим для подключения проводника – clamp for connecting conductor
Calculation of a grounding device resistance:
Horizontal electrode resistance:
- p — soil resistivity, Ohm*m;
- b — width of the horizontal electrode tape, m;
- h — laying depth of the horizontal mesh, m;
- Lгор — horizontal electrode length, m.
Vertical electrode resistance:
t – deepening of the electrode top, m
Impedance of the grounding device:
Where n - number of kits;
kисп - coefficient of use;
The design resistance of the grounding device is 3.94 ohms.
The list of required materials:
|№ п/п||Fig.||Product item||Product||Quantity|
|1.||ZZ-000-030||ZANDZ Universal grounding kit (30 meters)||1|
|2.||GL-11075-20||GALMAR copper-bonded tape (30 * 4 mm / S 120 mm², coil of 20 meters)||1|
|3.||GL-11075-10||GALMAR Copper-bonded tape (30 * 4 mm / S 120 mm², coil of 10 meters)||1|
See further - Appendix № 4. Local costing № 031 (application of ZANDZ modular grounding of vertical steel rods with the diameter of 14 mm and 1,5 long, covered by electrolytic deposition of copper with the purity of 99.9%, with the coating thickness 250 micron).
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