# LIGHTNING PROTECTION AND GROUNDING OF A DEPOT

Is it necessary to make lightning protection and grounding for a depot? There is a concentration of a great number of expensive electric equipment at such objects and in case of a lightning strike, the consequences can be unpleasant.

ZANDZ Technical Center got a task to develop solution on grounding and lightning protection of a depot. Let's see what solutions were offered.

Initial data:

• object: depot for service and repair of locomotives;

• sizes: 69 m x 31 m x 18 m;

• soil resistivity - 100 Ohm * m.

Calculate systems of lightning protection and grounding.

Solution:

Lightning protection and grounding of a depot are performed in accordance with:

The object refers to III category of lightning protection in accordance with AD and to "ordinary" in accordance with IS.

The set of measures on the provision of required lightning protection measures to lightning protection and grounding systems for depot is presented by the following solutions:

1. Lightning protection is carried out with the help of a lightning mesh with a distance between the cells of not more than 10 m. The mesh is made of steel copper-bonded wire (the tickness of the copper coating is not less than 70 mcm), the diameter of the wire is d8 mm (GL-11149).

2. Copper-bonded steel wire is used as down conductor (thickness of the copper coating not less than 70 mcm), d8mm wire (GL-11149).

3. Installation of down conductors is carried out with the help of clamp  GL-11747A - on the roof, GL-11703A -on vertial surfaces.  Distance between the clamps- from 0.8 up to 1.0 meter.

4. To connect rolled metal over the length and in the mesh nodes, a universal clamp GL-11551A is used.

5. All metal elements, placed on the roof must be connected to the down conductor with the help of clamps GL-11545A. Stairs and hand railings are connected with the help of a clamp-bridge GL-11514.

6. Copper-coated steel electrodes 3 m long are used in places of downdrops as a vertical ground electrodes. Copper-bonded steel tape with the cross-section of 30x4 mm (GL-11075) uniting all vertical electrodes is used as a horizontal ground electrode system. The distance to the object foundation- not less than 1 m. Burial depth of the tape 0,5-0,7 m.

7. In accordance with the EIC-7 ed., P.1.7.55 - Grounding devices for protective grounding of electrical installations of buildings and structures and lightning protection of the 2nd and 3rd categories of these buildings and structures, as a rule, should be common.

8. The design resistance of the grounding device (upper) is 1,87 Ohm (bottom) - 3.55 Ohm.

9. All metal reinforce concrete framings must be connected to down conductors / grounding device.

10. Connection to the grounding device is carried out with the help of clamps ZZ-005-064.

Grounding device resistance calculation:

Bottom:

The design resistance of the grounding device is 3.55 ohms.

Upper:

The design resistance of the grounding device is 1,87 Ohm.

Location of equipment is shown in figure 1.

Figure 1 - Arrangement of lightning protection and grounding equipment of a depot.

The list of equipment is given in Table 1.

Table 1 - Materials requirement list.

 № Product item Name Quantity, pieces. Weight, kg 1. GL-11149-50 GALMAR Copper-bonded wire (D 8mm / S 50 mm²; coil of 50 meters) 19 0,41 2. GL-11545A GALMAR Clamp on the gutter for a down conductor (painted galvanized steel) 20 0,112 3. GL-11551A GALMAR Clamp for connecting down conductors (painted galvanized steel) 90 0,07 4. GL-11747A GALMAR Clamp for the roof covered with metal profiles / corrugated sheets, for down conductor (painted galvanized steel) 750 0,05 5. GL-11703A GALMAR Clamp to the facade for down conductor with its elevation above the clamp to 15 mm (painted galvanized steel) 300 0,02 6. GL-11514N GALMAR Clamp-bridge on a gutter for down conductor (tinned copper) 20 0,076 7. GL-11075-50 GALMAR Copper-bonded tape (30 * 4 mm / S 120 mm²; coil of 50 meters) 4 0,98 8. ZZ-001-065 ZANDZ Copper-bonded threaded grounding pin (D14; 1,5 m) 24 2,00 9. ZZ-002-061 ZANDZ Threaded coupler 13 0,08 10. ZZ-003-061 ZANDZ Starting tip 12 0,07 11. ZZ-004-060 ZANDZ Driving head for a jackhammer 5 0,09 12. ZZ-005-064 ZANDZ Clamp for connecting conductor (up to 40 mm) 30 0,312 13. ZZ-006-000 ZANDZ Conductive grease 2 0,15 14. ZZ-007-030 ZANDZ Waterproof tape 8 0,40 15. ZZ-008-000 ZANDZ Header for a jackhammer (SDS max) 1 0,50

Do you have questions or need to calculate lightning protection and grounding for a depot? Send your request to info@zandz.ru.