The ZANDZ Technical Center has received a request to calculate the functional grounding arrangement for the stadium in Sochi. The calculation was made in two ways: conventional calculation and calculation using a software developed by OAO "Energy Institute named after G.M. Krzhizhanovsky" (OAO "ENIN").
Initial data:
- soil resistivity:
top layer - 150 Ohm*m;
lower layer - 70 Ohm*m;
- available area: triangle 15 x 7 m.
Task:
to calculate functional grounding arrangement with the resistance not exceeding 2 Ohm.
Solution:
A set of measures to ensure the requirements for the grounding arrangement of a football stadium is based on the following solutions:
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Installation of 6 vertical electrodes. Electrodes are combined using a horizontal grounding arrangement.
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Steel copper-plated rods D = 17 mm, L = 30 m are used as a vertical grounding arrangement. The thickness of the copper coating is at least 250 mcm.
-
A steel copper-plated bar 30 x 4 mm is used as a horizontal grounding arrangement. The thickness of the copper coating is at least 70 mcm. Depth is 0.5 to 0.7 m.
-
Connection to the grounding device is carried out using a GL-10333N clamp.
Ground terminal resistance calculation:
Equivalent resistivity of a double-layer soil:
ρ_экв=(ρ_1∙ρ_2∙L)/(ρ_1∙(t+L-h)+ρ_2∙(h-t)) = 77,6 Ohm;
where ρ_1 is top soil layer resistivity, 150 Ohm·m;
ρ_2 is lower soil layer resistivity, 70 Ohm·m;
h - is top soil layer depth, 6 m;
L is electrode length, 30 m;
t is horizontal electrode depth, 0.5 m;
seasonal ratio is not used.
Vertical electrode resistance::
Верт - Vert
Экв - Eq
Ом - Ohm
where ρρeq is equivalent soil resistivity, 77.6 Ohm·m;
L is vertical electrode length, 30 m;
d is vertical electrode diameter, 0.017 m;
T is depth, i.e. the distance from the ground surface to the ground electrode, 15.5 m;
where t is electrode top depth, 0.5 m.
Horizontal electrode resistance:
Гор - Hor
Ом - Ohm
where ρ is soil resistivity, 150 Ohm·m;
b is horizontal electrode width, 0.03 m;
h is horizontal electrode depth, 0.5 m;
Lгор is horizontal electrode length, 38 m;
Electrical impedance of the grounding arrangement:
ЗУ - GA
Ом - Ohm
where n is a number of sets, vertical grounding arrangements - 6 pcs, horizontal grounding arrangement - 1 pc;
Kutil is utilization rate, 0.45.
Results of the calculations performed by using the software developed by OAO G.M. Krzhizhanovskiy Energy Institute (OAO ENIN):
Панель результатов 1 - Result panel 1
ПАНЕЛЬ РЕЗУЛЬТАТОВ РАСЧЕТА - CALCULATION RESULT PANEL
Контур образован набором горизонтальных и вертикальных электродов с координатами, задаваемыми Пользователем - The circuit is formed by a set of horizontal and vertical electrodes with the coordinates set by the User
РЕЗУЛЬТАТЫ РАСЧЕТА - CALCULATION RESULTS
Сопротивление контура заземления – 1,245 Ом - Grounding circuit resistance – 1.245 Ohm
Напряжение на контуре заземления – 1,25 В - Grounding circuit voltage – 1.25 V
Коэффициент использования контура Ks = 0,4135 - Circuit utilization ratio Ks = 0.4135
Суммарная длина электродов контура – 218,6 м - Total circuit electrode length – 218.6 m
ОКНА ПРОСМОТРА ПАРАМЕТРОВ ОБЪЕКТОВ - FACILITY PARAMETERS VIEW
Для отображения информации в окнах просмотра – нажмите клавишу «Просмотр» в интересующем Вас «БЛОКЕ ПРОСМОТРА» - To show information in the views, press “View” button in the “VIEW UNIT” of interest
Повторить расчет - Repeat calculation
БЛОКИ ПРОСМОТРА - VIEW UNITS
Сохранить результаты расчета в текстовом файле - Save calculation results in a txt file
Для выхода из программы – нажмите клавишу «Закончить работу» - Press “Finish work” to exit the application
Закончить работу - Finish work
Горизонтальные электроды - Horizontal electrodes
Просмотр - View
Вертикальные электроды - Vertical electrodes
Просмотр - View
Потенциальные точки - Potential points
Просмотр - View
Добавить точки - Add points
Расчет проведен при следующих параметрах: - Calculation is performed using the following parameters:
Тестовый ток – 1,0 А - Test current – 1.0 A
Глубина заложения контура – 0,50 м - Circuit depth – 0.50 m
Удельное сопротивление грунта – 77,60 Ом.м - Soil resistivity – 77.60 Ohm.m
Estimated resistance of a grounding arrangement is 1,23 Ohm and 1.,45 Ohm, which is less than the required resistance of 2 Ohm.
The location of the equipment is shown in Figure 1.
The list of the required materials based on the calculation results is shown in Table 1.
7 м - 7 m
Условные обозначения: - Legend:
- полоса стальная оцинкованная сечением 30х4 мм - Steel zinc-plated bar with cross-section 30 x 4 mm
- зажим для соединения проводников - Clamp for connecting conductors
- Вертикальный заземлитель длиной 30 м - 30 m vertical grounding electrode
Figure 1. Equipment layout.
Table 1. List of needed materials.
| Item # | Part number | Name | Quantity, pcs. |
| 1. | GL-10021 | GALMAR Copper-plated threaded grounding rod (D17; 1.2 m) | 150 |
| 2. | GL-10403 | GALMAR Threaded coupling (D17) | 145 |
| 3. | GL-10603 | GALMAR Termination (D17) | 6 |
| 4. | GL-10803 | GALMAR Guide head for jackhammer attachment (D17) | 30 |
| 5. | GL-10333N | GALMAR Clamp for connecting conductor (D17; p. <40 mm; stainless steel) | 7 |
| 6. | ZZ-006-000 | ZANDZ Conductive grease | 15 |
| 7. | ZZ-007-030 | ZANDZ Waterproofing tape | 2 |
| 8. | ZZ-008-000 | ZANDZ Attachment to the hammer (SDS max) | 2 |
| 9. | GL-11075-50 | GALMAR Copper-plated strip (30 * 4 mm / S 120 mm²; 50-meter strip bundle) | 1 |
Do you have any questions about the football stadium grounding? Please contact the ZANDZ Technical Center!
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