Example Calculation of Lightning Protection System for a Chemical Analysis Laboratory

The ZANDZ Technical Center has received a request to calculate the lightning protection system for a chemical analysis laboratory located in the European part of Russia. Let's consider the solution offered by our specialists.

Lightning protection of a chemical analysis laboratory

Calculation data:

  1. Facility: chemical analysis laboratory.

  2. Facility drawing.

  3. Soil resistivity: 100 Ohm*m.



  • calculate the lightning protection system;

  • calculate the grounding arrangement.



Lightning protection and grounding of the building are made in accordance with:


The facility is "special, environmentally hazardous" from the viewpoint of SO and is classified as Category I of the lightning protection according to RD.


A set of measures to provide the necessary requirements to the lightning protection system and to the grounding arrangement for the chemical analysis laboratory includes the following solutions:

  1. The lightning protection is made using 16 m lightning masts (ZZ-201-016-B7-Sn5-S9). The lightning arresters are installed on concrete foundations. The distance to the facility is at least 3 m.

  2. The protection zone should include space over the valves, r = 5 m; h = 2.5 m.

  3. Copper-plated steel electrodes 3 m long are used as a vertical grounding arrangement.

  4. 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 mast foundation is at least 1 m. Strip deepening is 0.5 to 0.7 m.

  5. Connection to the grounding arrangement is made through clamps ZZ-005-064.


The results of calculation of protection zones according to SO:

h = 16 m;

Cone height according to SO, Table 3.4:

Height of a lightning protection cone

м - m

Cone radius according to SO, Table 3.4:

Radius of a lightning protection cone

м - m

The distance (maximum) between lightning arresters:

L = 22 m;

Limit distance between lightning arresters according to SO, Table 3.6:

Limit distances between lightning arresters

м - m

There is not sagging height.

For the protection zone with the required reliability, radius rx at the height of h0 = 7.5 m is defined as:

Protection zone at the pre-determined height


м - m

Ground terminal resistance calculation:

Vertical electrode resistance:

Vertical grounding electrode resistance

Ом - Ohm

where ρeq is equivalent soil resistivity, 100 Ohm·m;

L is vertical electrode length, 3 m;

d is diameter of the vertical electrode, 0.014 m;

T is deepening, i.e. the distance from the ground surface to the ground electrode, 2 m;

Vertical grounding electrode deepening

where is deepening of the electrode top, 0.5 m.


Horizontal electrode resistance:

Calculation of a horizontal grounding electrode

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 is horizontal electrode length, 79 m.


Electrical impedance of the grounding arrangement:

Impedance of a grounding arrangement

Ом - Ohm

where n is a number of sets, vertical grounding arrangements - 7 pcs, horizontal grounding arrangement - 1 pc;

Kutil is utilization rate, 0.69.


The rated resistance of the grounding arrangement is 2,51 Ohm.


The equipment layout and the protection zone are shown in Fig. 1.

Lightning protection and grounding system for a chemical analysis laboratory

Условные обозначения - Key
Молниеприемник-мачта высотой 16 м - Lightning arrester, 16 m high
Полоса стальная оцинкованная сечением 30х4 мм - Steel zinc-plated bar with cross-section 30 x 4 mm
Зажим для подключения проводов - Clamp for connecting wires
Вертикальный заземлитель длиной 3 м - Vertical grounding electrode, 3 m long
Зона защиты h = 7,5 м - Protection zone h = 7.5 m
Защищенное пространство над клапанами r=5 м; h=2,5 м - Protected space above valves, r = 5 m; h = 2.5 m

Figure 1. Equipment layout.


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. ZZ-201-016-В7-Сн5-С9 ZANDZ Lightning arrester, vertical, 16 m (zinc-plated steel; with embedded elements for the foundation; 7th wind region; 5th snow region; 9th seismic region) 4    
2. GL-11075-50 GALMAR Copper-plated strip (30 * 4 mm / S 120 mm²; 50-meter strip bundle) 1 0,98 Вес за 1 м
3. GL-11075-20 GALMAR Copper-plated bar (30 * 4 mm / S 120 mm²; bundle 20 meters) 2 0,98 Вез за 1 м
4. ZZ-001-065 ZANDZ Copper-plated threaded grounding pin (D14; 1.5 m) 14 2,00  
5. ZZ-002-061 ZANDZ Threaded coupling 8 0,08  
6. ZZ-003-061 ZANDZ Takeoff tip 7 0,07  
7. ZZ-004-060 ZANDZ Guide head for jackhammer attachment 3 0,09  
8. ZZ-005-064 ZANDZ Conductor connection terminal (up to 40 mm) 15 0,312  
9. ZZ-006-000 ZANDZ Conductive grease 1 0,10  
10. ZZ-007-030 ZANDZ Waterproofing tape 5 0,40  
11. ZZ-008-000 ZANDZ Attachment to the hammer (SDS max) 1 0,50  

Do you have any questions regarding lightning protection and grounding for the chemical analysis laboratory? Please contact the ZANDZ Technical Center!

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