Lightning protection for a tourist camp!

11.11.16

Vacations are widely popular at any time of year, so there are tourist camps in almost all parts of the world. Normally, they are located quite a distance from populated localities. Such facilities must be protected against external hazards, in particular, a direct lightning strike. Otherwise, that could result in serious consequences.

One of our partners asked the ZANDZ technical center, "How can we set up lightning protection for a tourist camp? What solution can you offer?"

The ZANDZ technical center responded promptly and suggested the following solution for the problem:

Object:

Specific resistance of the soil used for calculations – 150 Ohm * m.

Tourist camps are referred to as "ordinary" according to the JI and are in the 3rd category as per RD. Required reliability - 0.9.

As per EIC 7, article 1.7.103. The total spreading resistance of the earthing electrodes (including natural) of all the repeated groundings of the PEN conductor in each overhead line at any time of the year must not exceed 10 ohms at a line voltage of 380 V for a three-phase power supply or 220 V for a single-phase power source.

Required arrangements for lightning protection

The action plan to ensure compliance with the necessary requirements for a lightning protection system is as follows:

• Setting up a conductor cable around the perimeter of the roof and its ridge, as well as making 1m high vertical elevations using copper-coated copper wire of D8 mm on the corners of the facility (see Fig.1).
• Installation of an earthing device consisting of 3 vertical electrodes of 3 m in length linked by a horizontal electrode (a copper-plated band of 30x4 mm). The distance from the horizontal electrode to the facility shall not be less than 1 m, embedded 0.5 - 0.7 meters deep.
• All metal objects on the roof shall be connected to conductor cables.

Calculation of resistance of the earthing device:

The design resistance of the grounding device is 9.24 Ohm, which is less than the permitted resistance of 10 Ohm.

Results of calculations performed with software developed by the G. M. Krzhizhanovsky Energy Institute:

The density of lightning discharges into the ground – 6 strikes / sq. km per year;

The total number of strikes into the system is 0.023 (one every 261 years).

Total number of breakthroughs is 0.00091.

System reliability is 0.96.

The probability of a breakthrough into all the system's objects – 0.004 (one every 1055 years).

Figure 1. Equipment layout.

Table 1. List of equipment and required materials.

 № Fig. Product item Name Quantity, pcs. 1. GL-11149-50 GALMAR Copper-coated wire (D 8mm / S 50 mm²; coil of 50 meters) 3 2. GL-11551A GALMAR Clamp for connecting conductor cables (painted galvanized steel) 25 3. GL-11747A GALMAR Clamp for the roof covered with metal profiles / corrugated sheets for conductor cables (painted galvanized steel) 110 4. GL-11703A GALMAR Clamp for fixing conductor cables to the facade (painted galvanized steel) 40 5. GL-11562A GALMAR Control clamp for connecting conductor cables, wire + tape (painted galvanized steel) 3 6. ZZ-001-065 ZANDZ Copper-plated threaded earthing rod (D14; 1.5 m) 6 7. ZZ-002-061 ZANDZ Copper-plated threaded earthing rod (D14; 1.5 m) 4 8. ZZ-003-061 ZANDZ Starting tip 3 9. ZZ-004-060 ZANDZ Driving head for a jackhammer 2 10. ZZ-006-000 ZANDZ Conductive lubricant 1 11. ZZ-008-000 ZANDZ Head for a jackhammer (SDS max) 1 12. ZZ-005-064 ZANDZ Clamp for connecting a conductor (up to 40 mm) 4 13. ZZ-007-030 ZANDZ Waterproof tape 1 14. GL-11075-20 GALMAR copper-plated tape (30 * 4 mm / S 120 mm²; coil of 20 meters) 1 15. GL-11075-10 GALMAR Copper-plated tape (30 * 4 mm / S 120 mm²; coil of 10 meters) 1 16. ZZ-500-110 ZANDZ Earthing conductor (10m; S25, single-core, with a tip for a D8 bolt) 1