Task:
Object: two-side railway loading rack for rendering services to railway wagons - tanks with a reversible gangway and boarding ladders 67,4х4,9х7,0 m (LxWxH).
Soil resisitivity: 100 Ohm*m
Solution
In accordance with the AD 34.21.122-87, railway unloading rack belongs to category II of lightning protection and must be protected from direct lightning strikes, its secondary effects and import of high potential via on-ground (above-ground) metal communications. Protection zone B is chosen in accordance with p.3 of the chart 1 of the AD 34.21.122-87. Protection against secondary effects of lightning and import of high potential is carried out by connecting metal constructions of railway loading rack to the grounding device. Protection of object against direct lightning strikes is carried out with the help of ZANDZ catenary wire lightning protection, having the following sizes:
h = hоп-2, at а < 120 m.
а = 75,7 m.
h = 16-2=14 m.
hо = 0,92*h = 0,92*14 = 12,9 m.
rо = 1,7*h = 1,7*14 = 23,8 m.
rх = 1,7*(h-hx/0,92) = 1,7*(14-7/0,92) = 10,9 m.
See the drawings of the present project to see the borders of the protection zones.
Grounding device with high-rise catenary wire lightning protection ZANDZ consists of 3 vertical electrodes (copper-bonded threaded rods D14, 1.5m ZZ-001-065 - 2 pieces per 1 electrode) and copper-bonded tape 30x4 GL-11075, connected with the help of a clamp for connecting conductor ZZ-005-064 in accordance with GOST 21130-75 (see the complete specification and links to the description of equipment below).
Carry out hydroinsulation for bolt connections and foresee the possibility of inspection of connections at any time.
Connect the grounding device to the lightning rod with the help of welding. The grounding device is laid at the depth of 0,5 m from the ground surface at the distance of 1 m from the support of catenary wire lightning protection system.
The own structure of the catenary wire lightning protection system support acts as a down conductor in accordance with p.3.2.2.5 IS 153-34.21.122-2003. Electric continuity between the different parts is provided for a long term.
The grounding device is organized at the nearest territory outside the protective zone of underground communications; its precise location is defined when building it.
Arrangement of the grounding device, see the layouts of the present project.
Carry out installation of lightning protection and grounding according to EIC, ed. 7, AD 34.21.122-87 "Instructions for lightning protection of buildings and structures" and IS 153-34.21.122-2003 "Instructions for lightning protection of buildings, structures and industrial communications", GOST 21130-75 "Electrotechnical products. Grounding clamps and signs. Design and dimensions".
Calculation of grounding device resistance:
Vertical electrode resistance:
where p - soil resistivity, ohm-m;
L - vertical electrode length, m;
d - vertical electrode diameter, m;
T - burial - the distance from the ground surface to the ground electrode, m;
Horizontal electrode resistance:
where ρ - soil resistivity, Ohm* m;
b - horizontal electrode tape width ,m;
Lгор - horizontal electrode length, m.
where t - deepening of the electrode top, m
Impedance of the grounding device:
where n - number of kits;
Kисп - utilization ratio.
The design resistance of the grounding device is 4.16 ohms, which is less than the permissible resistance of 10 ohms.
The list of required materials:
| № п/п | Fig. | Product item | Name | Quantity | Weight, unit, kg |
| 1. |  |
ZZ-001-065 | ZANDZ Copper-bonded threaded grounding rod (D14; 1,5 m) | 12 | 1,9 |
| 2. |  |
ZZ-002-061 | ZANDZ Threaded coupler | 8 | 0,08 |
| 3. |  |
GL-11703A | ZANDZ Starting tip | 6 | 0,07 |
| 4. |  |
ZZ-004-060 | ZANDZ Driving head for a breaker hammer | 3 | 0,09 |
| 5. |  |
ZZ-005-064 | ZANDZ Clamp for connecting conductor (up to 40 mm) | 6 | 0,31 |
| 6. |  |
ZZ-006-000 | ZANDZ Conductive grease | 2 | 0,19 |
| 7. |  |
ZZ-007-030 | ZANDZ Water-proof tape | 6 | 0,442 |
| 8. |  |
ZZ-008-000 | ZANDZ Driving head for a breaker hammer (SDS max) | 1 | 0,48 |
| 9. |  |
GL-11402 | GALMAR Inspection pit | 6 | 2,6 |
| 10. |  |
GL-11075 | GALMAR copper bonded tape 30x4 mm | 30 | 0,98 (in meters) |
| 11. |  |
ZZ-204-001 | ZANDZ Galvanized steel ground wire (50 mm2) | 85 | - |
| 12. |  |
ZZ-204-115 | ZANDZ Base of catenary wire protection system with one node of wire fixation (suspension height - 15 m) | 2 | - |
Appendix: the project is available in DWG and PDF formats
Files in the formats DWG and PDF are available for downloading only for authorized users.
Do you need to make the project on grounding and lightning protection? Order it by contacting the ZANDZ Technical Center!
Related Articles:
Lightning Protection Design for a Railroad Terminal and Station
A series of webinars on the modern methods of lightning protection with LEC representatives
Typical Design "Lightning Protection and Grounding for a School"
A series of webinars about ZANDZ.com Expert Club