Lightning Protection and Grounding of a Cheese Factory in the Ryazan Region

The ZANDZ Technical Center has received a request to calculate the lightning protection and grounding system for the cheese factory in the Ryazan Region. Let's further consider the solution.

Lightning protection of a cheese factory

Initial data:

  • facility: cheese factory;

  • dimensions: 30.4 mm x 52 m;

  • height: 10 m;

  • soil resistivity: 100 Ohm*m.



  • calculate the lightning protection system;

  • calculate the grounding device.



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


The facility is classified as conventional in terms of SO and to Category III of lightning protection according to RD. The required reliability of the lightning protection system shall be at least 0.9.


A set of measures to meet the necessary requirements to the lightning protection system and to the grounding arrangement of the cheese factory includes the following solutions:

  1. The facility lightning protection is made using 4 m lightning arresters (ZZ-201-004). The masts are secured to the facade using brackets.

  2. A steel copper-plated wire d8 mm (GL-11149) is used as a lightning arrester.

  3. Current collectors are installed using clamps GL-11711 on the roof and GL-11703A on vertical surfaces. The clamp installation spacing is 0.8 to 1.0 m.

  4. The current collector downdrops are made along the waterspouts.

  5. The universal GL 11551A clamp is used to connect the rolled products over the length and in assemblies.

  6. All metal elements located on the roof shall be connected to the down conductor using GL 11545A clamps. Stairs, railings, are attached using the GL 11514N ring clamp.

  7. Copper-plated steel electrodes 3 m long in the locations of the current collector downdrops are used as vertical ground electrodes.

  8. The copper-plated steel strip with a cross-section of 30 x 4 mm, interconnecting 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.

  9. According to EIC-7 issue, par.1.7.55, Grounding devices for protective grounding of electrical installations for buildings and structures and Categories 2 and 3 of lightning protection of these buildings and structures, as a rule, shall be common.

  10. If there are concrete-steel constructions, they shall be connected to down conductors/grounding device.

  11. Connection to the grounding device is carried out using ZZ-005-064 clamps.


Calculation results carried out using software developed by the G.M. Krzhizhanovsky Energy Institute, JSC ENIN

The occurrence of lightning strokes into the ground is 4 strokes/sq. km per year

The total number of strikes into the system is 0.049 (once every 20 years).

The total number of breakouts into the system is 0.0021 (once every 476 years).

The system reliability is 0.957;

The probability of breakout into all facilities of the system is 0.043.


Ground terminal resistance calculation:

Vertical electrode resistance:

Calculation of a vertical grounding arrangement

Верт - Vert
Экв - Eq
Ом - Ohm

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

L is vertical electrode length, 3 m;

d is vertical electrode diameter, 0.014 m;

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

Grounding arrangement depth

м - m

where t is deepening of the top of the electrode, 0.5 m.


Horizontal electrode resistance:

Calculation of a horizontal grounding arrangement

Гор - Hor
Ом - Ohm

where ρ is soil resistivity, 100 Ohm·m;

b is horizontal electrode width, 0.03 m;

h is horizontal electrode depth, 0.5 m;

Lгор is horizontal electrode length, 32 m.


Electrical impedance of the grounding arrangement:

Calculation of resistance of a grounding arrangement

Ом - Ohm

where n is a number of sets, vertical grounding arrangements - 2 pcs, horizontal grounding arrangement - 1 pc;

Kutil is utilization rate, 0.81.

The rated resistance of the grounding device is 5.29 Ohms.


The location of the equipment is shown in Figure 1.

Lightning protection and grounding for a cheese factory

Условные обозначения - Legend
- молниеприемник-мачта высотой 4 м - 4 m lightning arrester
- проволока стальная омедненная диаметром 8 мм - steel copper-plated wire 8 mm
- полоса стальная омедненная сечением 30х4 мм - steel copper-plated bar 30 x 4 mm
- зажим для подключения проводника - wire connection clamp
- опуск токоотвода - downdrop
- вертикальный заземлитель длиной 3 м - 3 m vertical grounding electrode

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-201-004 ZANDZ Tower interception rod, 4 m (stainless steel) 8 8,50  
2. ZZ-203-001 ZANDZ Wall fastening for interception rod (stainless steel) 8 14,665  
3. ZZ-202-001 ZANDZ Interception rod terminal for main conductor cables (stainless steel) 8 0,20  
4. GL-11149-50 GALMAR Copper-plated wire (D 8 mm/S 50 mm²; 50-meter bundle) 5 0,41 Вес 1 м
5. GL-11551A GALMAR Conductor connection clamp (painted zinc-plated steel) 20 0,07  
6. GL-11711 GALMAR Flat roof terminal for the conductor cable (plastic, concrete) 50 1,20  
7. GL-11703A GALMAR Current collector facade clamp providing 15 mm elevation of the collector over the clamp (painted zinc-plated steel) 220 0,02  
8. GL-11075-20 GALMAR Copper-plated bar (30 * 4 mm / S 120 mm²; bundle 20 meters) 2 0,98 Вес 1 м
9. ZZ-001-065 ZANDZ Copper-plated threaded grounding rod (D14; 1,5 m) 4 2,00  
10. ZZ-002-061 ZANDZ Threaded coupling 3 0,08  
11. ZZ-003-061 ZANDZ Termination 2 0,07  
12. ZZ-004-060 ZANDZ Guide head for jackhammer attachment 1 0,09  
13. ZZ-005-064 ZANDZ Conductor connection terminal (up to 40 mm) 6 0,312  
14. ZZ-006-000 ZANDZ Conductive grease 1 0,10  
15. ZZ-007-030 ZANDZ Waterproofing tape 2 0,40  
16. ZZ-008-000 ZANDZ Attachment to the hammer (SDS max) 1 0,50  

Do you have any questions regarding lightning protection and grounding of the cheese factory? Please contact the ZANDZ Technical Center!

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