The Chemical Workshop is used to organize water treatment processes and control the water-chemical regime of the power plant equipment. There are no special requirements for lightning protection of workshops according to regulatory documents. It is important to ensure the required reliability of lightning protection. A request with a wish to protect the Chemical Workshop by means of interception discharge rods has been recently delivered to the ZANDZ Technical Center Let us continue with more detailed review of our offered solution.
Calculation of lightning protection of a chemical workshop
Object: chemical workshop
Figure 1 – Object layout.
Task: Perform calculations of the lightning protection system of a Chemical Workshop.
Protection of the buildings and structures against lightning strikes is provided by using lightning dischargers. The lightning discharger – is a device which is elevated over the facility, through which the lightning current goes into the ground bypassing the protected facility. It consists of a interception rod, which is specially designated to arrest the lightning discharge, a conductor cable and a ground electrode.
Solutions to fulfil the requirements for the lightning protection system of a Chemical Workshop:
The lightning protection is made in accordance with Electrical Installations Code (EIC)., Rev. 7, SO 153-34.21.122-2003 "Guidelines for the lightning protection of buildings, structures and industrial infrastructure" (further – SO) and WD 34.21.122-87 "Guidelines for the lightning protection of buildings and structures" (further – WD).
- The facility belongs to the III class according to WD. The system reliability shall be at least 0.9.
- Lightning protection of the facility is performed using 14 interception rods of tower type with a height of 2 m (GL-21101G) attached to the wall by fasteners. 0.5 meters of the interception rod is reserved for mounting.
- Steel copper-clad wire, D8 mm (GL-11149) (copper coating thickness of at least 70 microns) is used as main conductor cable.
- The installation of main conductor cable is carried out using the fastener GL-11703A - on vertical surfaces. The accepted pitch of terminals is 0.8-1.0 m.
- The universal terminal GL-11551A is used to connect rolled products along the length and in joints.
- All metal elements located on the roof must be connected to the main conductor cable with the terminals GL-11545. Stairs, railings, are attached using the terminal-clamp GL-11514N.
- The existing grounding arrangement.
- Connection to the grounding arrangement is made through the terminals ZZ-005-064.
Figure 2 shows hardware layout.
Table 1 includes the list of required hardware and materials.
Рисунок 2 - Расположение оборудования для молниезащиты химического цеха.
Условные обозначения - Conventional symbols
Молниеприемник-мачта высотой 2 м на держателях к стене (GL-21101G) - Interception rod tower 2 m high, fastened to the wall (GL-21101G)
Проволока стальная омедненная диаметром 8 мм (GL-11149) - Copper-clad steel wire with a diameter of 8 mm (GL-11149)
Универсальный зажим-соединитель для проволоки (GL-11551A) - Universal Wire Connection Terminal (GL-11551A)
Фальцевая клемма для крепления к металлическим конструкциям (GL-11545A) - Folding terminal for attachment to the metalworks (GL-11545A)
Зажим-хомут (GL-11514) - Terminal-clamp (GL-11514)
Зажим для подключения проводника (ZZ-005-064) - Main conductor connection terminal (ZZ-005-064)
Опуск токоотвода - Main conductor cable downdrop
Figure 2 – layout of hardware for lightning protection of a Chemical Workshop.
|1.||GL-21101G||Vertical interception rod GALMAR (interception rod tower) (2 meters)||14|
|2.||ZZ-203-001||ZANDZ wall fastening for interception rod (stainless steel)||14|
|3.||GL-20022||The interception rod tower terminal GALMAR GL-21101G/GL-21102G/GL-21103G for main conductors (stainless steel)||14|
|4.||GL-11149-50||Copper-clad wire GALMAR (D 8 mm/S 50 mm²; 50-meter bundle)||9|
|5.||GL-11551A||Terminal GALMAR for main conductors connection (painted galvanized steel)||60|
|6.||GL-11703A||Conductor front terminal GALMAR providing 15mm elevation of the main conductor over the terminal (painted galvanized steel)||450|
|7.||GL-11545A||Main conductor rain water gutter terminal GALMAR (painted galvanized steel)||10|
|8.||GL-11514N||GALMAR terminal for fastening the main conductor to a drain pipe (tinned copper strip + stainless steel terminal)||10|
|9.||ZZ-005-064||ZANDZ Conductor connection terminal (up to 40 mm)||10|
Do you have any questions about lightning protection of workshops or other facilities? Please, contact the ZANDZ Technical Center!