The ZANDZ Technical Center has received a request to calculate the lightning protection system for the church in the European part of the Russian Federation. Our experts have developed a following solution.
Calculation data:
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Facility: a church.
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Facility drawing.
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Soil resistivity: 100 Ohm*m.
Task:
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calculate the lightning protection system;
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calculate the grounding arrangement.
Solution:
Lightning protection and grounding of the building are made in accordance with:
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SO 153 34.21.122 2003 "INSTRUCTIONS FOR MOUNTING LIGHTING PROTECTIONS OF BUILDINGS, STRUCTURES AND INDUSTRIAL COMMUNICATIONS", hereinafter referred to as SO;
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RD 34.21.122 87 "INSTRUCTIONS FOR MOUNTING LIGHTING PROTECTION OF BUILDINGS AND STRUCTURES", hereinafter referred to as RD.
The facility is "conventional" from the viewpoint of SO and refers to category III of the lightning protection according to RD.
A set of measures to meet the necessary requirements to the lightning protection system and to the grounding arrangement of the church includes the following solutions:
1. A metal cross and the facility's dome are used as a lightning arrester.
2. A copper-plated steel wire (copper coating thickness of at least 70 μm), d8 mm (GL-11149) is used as a current collector.
3. The current collectors are installed using the GL-11704A clamp to be attached by welding. The clamp installation spacing is 0.8 to 1.0 m.
4. The multifunctional GL-11551A clamp is used to connect rolled products over the length and in assemblies.
5. All metal elements located on the roof should be connected to the current collectors.
6. The crosses are connected to the current collector using collar clamps GL-11514N.
7. Copper-plated steel electrodes 3 m long in the places of the current collector downdrops are used as vertical ground electrodes. The copper-plated steel strip with a cross-section of 30 x 4 mm, combining all vertical electrodes, is used as a horizontal ground electrode. The distance to the facility foundation is at least 1 m. Strip deepening is 0.5 to 0.7 m.
8. According to the EIC, 7th rev., item 1.7.55, grounding devices for protective grounding of electrical installations for buildings and structures and the 2nd and 3rd categories lightning protection of these buildings and structures usually should be common.
9. If there are reinforced concrete structures, they should be connected to current collectors/grounding arrangement.
10. Connection to the grounding arrangement is made with clamps ZZ-005-064.
Ground terminal resistance calculation:
Vertical electrode resistance:
Ом - Ohm
Where ρρeq (ρэкв) – is soil equivalent resistivity, 100 ohm·m;
L – is vertical electrode length, 3 m;
d – is diameter of the vertical electrode, 0,014 m;
T – deepening - is the distance from the ground surface to the ground electrode, 2 m;
where t – is deepening of the top of the electrode, 0.5 m
Horizontal electrode resistance:
Ом - Ohm
where ρ – is soil resistivity, 100 ohm·m;
b - is horizontal electrode width, 0.03 m;
h - is horizontal electrode depth, 0.7 m;
Lhor (Lгор) is horizontal electrode length, 10 m.
Electrical impedance of the grounding arrangement:
Ом - Ohm
where n – is a number of sets, vertical grounding arrangements 2 pcs, horizontal grounding arrangement 1 pc;
Kutil (Kисп) – is utilization rate, 0.81.
The design resistance of the grounding arrangement is 7,75 ohm.
The results of calculation of protection zones according to SO:
h = 12,5 m;
Cone height according to SO, Table 3.4:
h0 = 0.85h = 10.63 m;
Cone radius according to SO, Table 3.4:
r0 = 1.2h = 15 m.
The equipment layout and the protection zone are shown in Fig. 1.
Figure 1. Equipment layout.
Условные обозначения - Legend
- проволока стальная омедненная диаметром 8 мм (GL-11149) - steel copper-plated wire having diameter 8 mm (GL-11149)
- полоса стальная омедненная сечением 30х4 мм (GL-11075) - steel copper-plated bar with cross-section 30 x 4 mm (GL-11075)
- универсальный зажим-соединитель для проволоки (GL-11551A) - multipurpose connecting clamp for wire (GL-11551A)
- зажим для подключения проводника (ZZ-005-064) - clamp for connecting wire (ZZ-005-064)
- вертикальный заземлитель длиной 3 м - vertical grounding arrangement 3 m long
Уровень чистого пола - Finish flooring level
Окно - Window
Зона защиты - Protection zone
The list of necessary materials is given in Table 1.
Table 1. List of needed materials.
|
№ |
Part number |
Name |
Quantity, pcs. |
Unit weight, kg. |
Note |
|
1. |
GL-11149-50 |
GALMAR Copper-clad wire (D 8 mm/S 50 mm²; 50-meter bundle) |
1 |
0,41 |
In meters |
|
2. |
GL-11551A |
Terminal GALMAR for main conductors connection (painted galvanized steel) |
5 |
0,07 |
|
|
3. |
GL-11747A |
GALMAR Roof clamp coated with metal profile, for current collectors (painted galvanized steel) |
30 |
0,02 |
|
|
4. |
GL-11703A |
Terminal GALMAR for fastening the main conductor cable with elevation (15 mm height; galvanized steel with painting) to the facade/wall |
30 |
0,02 |
|
|
5. |
GL-11514N |
GALMAR terminal for fastening the main conductor to a drain pipe (tinned copper strip + stainless steel terminal) |
2 |
|
|
|
6. |
GL-11075-20 |
GALMAR Copper-plated strip (30*4 mm/ S 120 mm²; 20-meter strip bundle) |
1 |
0,98 |
In meters |
|
7. |
ZZ-001-065 |
ZANDZ Copper-plated threaded grounding rod (D14; 1,5 m) |
4 |
2,00 |
|
|
8. |
ZZ-002-061 |
ZANDZ Threaded coupling |
3 |
0,08 |
|
|
9. |
ZZ-003-061 |
ZANDZ Termination |
2 |
0,07 |
|
|
10. |
ZZ-004-060 |
ZANDZ Guide head for jackhammer attachment |
1 |
0,09 |
|
|
11. |
ZZ-005-064 |
ZANDZ Conductor connection terminal (up to 40 mm) |
5 |
0,312 |
|
|
12. |
ZZ-006-000 |
ZANDZ conductive grease |
1 |
0,10 |
|
|
13. |
ZZ-007-030 |
ZANDZ Waterproofing tape |
2 |
0,40 |
|
|
14. |
ZZ-008-000 |
ZANDZ Attachment to the hammer (SDS max) |
1 |
0,50 |
|
Do you have questions regarding lightning protection and grounding of the church? Please, contact the ZANDZ Technical Center!
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