The ZANDZ Technical Center has received a request to calculate the functional grounding arrangement for a commissioning area. Let's consider the offered solution.
The soil resistivity accepted for calculations is 500 Ohm * m.
To calculate functional grounding arrangement with the resistance not more than 1 Ohm.
Grounding is made in accordance with the EIC, Rev. 7, Chapter 1.7.
A set of arrangements ensuring compliance with the requirements is based on the following solutions:
- installation of 39 sets of a vertical electrolytic grounding ZZ-100-102MB, which are combined using a corrosion-resistant steel copper-plated bar with a cross-section 30 x 4 mm;
- distance between the electrodes and from the electrode to the facility is at least 3 m, depth is 0.5-0.7 m;
- connection is made using clamps ZZ-005-064.
Ground terminal resistance calculation:
Resistance of the ZZ-100-102MB set:
Ом - Ohm
Верт - Vert
where C is a non-dimensional factor, describing the electrolyte content in the surrounding soil, 0.25;
ρ – is soil equivalent resistivity, 500 Ohm m;
L is vertical electrode length, 3 m;
d is vertical electrode diameter, 0.065 m;
Horizontal electrode resistance:
Гор - Hor
where ρ is soil resistivity, 500 Ohm·m;
b is horizontal electrode width, 0.03 m;
h is horizontal grounding depth, 0.5 m;
Lhor is horizontal electrode length, 168 m.
Electrical impedance of the grounding arrangement:
ЗУ - GA
where n – is a set number, 39 pcs, horizontal grounding electrodes - 1 pc;
kutil is a utilization ratio of sets - 0.8; of horizontal grounding electrode - 0.7;
rated resistance of the grounding arrangement is 0,98 Ohm, which is less than the required value of 1 Ohm.
The location of the equipment is shown in Figure 1.
Комплект электролитического заземления - Electrolytic grounding set
Полоса омедненная 30х4 мм - Copper-plated bar 30 x 4 mm
Figure 1. Layout of grounding arrangement parts
Table 1. List of required materials.
|№||Part number||Name||Quantity, pcs|
|1.||ZZ-100-102МВ||ZANDZ Electrolytic grounding kit (vertical; 3 meters)||39|
|2.||GL-11075-50||GALMAR Copper-plated strip (30 * 4 mm / S 120 mm²; 50-meter strip bundle)||4|
|3.||GL-11075-20||GALMAR Copper-plated strip (30 * 4 mm/ S 120 mm²; 20-meter strip bundle)||1|
|4.||ZZ-007-030||ZANDZ Waterproofing tape||15|
|5.||ZZ-005-064||ZANDZ Conductor connection terminal (up to 40 mm)||45|
Do you have any questions about grounding of a commissioning area or other facilities? Please, contact the ZANDZ Technical Center!