Rotators' camps are built for the servicing personnel near oil and gas fields. Such structures should be protected from lightnings and grounded. The facility is conventional according to regulatory documents and does not imply any specific requirements for the lightning protection, but it is important to protect the structure. The ZANDZ Technical Center has received a request to calculate the lightning protection for a rotators' camp in the Yamal-Nenetsk Autonomous District. Let us continue with more detailed review of our offered solution.
Calculation of lightning protection for the rotators' camp in the Yamal-Nenetsk Autonomous District
Facility: rotators' camp in the Yamal-Nenetsk Autonomous District
Figure 1. Facility plan.
Task: To calculate the lightning protection system for the rotators' camp in the Yamal-Nenetsk Autonomous District
Solutions to meet the requirements to the lightning protection system for the rotators' camp in the Yamal-Nenetsk Autonomous District:
- 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" (hereinafter referred to as SO) and RD 34.21.122-87 "Guidelines for the lightning protection of buildings and structures" (hereinafter referred to as the RD).
- According to RD, the facility is considered as the 3rd category lightning protection facility. The system reliability shall be at least 0.9.
- The facility lightning protection is made via using 2 m lightning masts installed on roof ridges (GL-11521SS).
- A copper-plated steel wire (copper coating thickness of 70 μm min.), d8 mm (GL 11149) is used as a down conductor.
- The down conductors are installed using holder GL-11564A on the roof ridge, using holder GL-11747A on the roof pitches, and using holder 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 vertical copper-plated steel electrodes with the length of 3 m are used as the grounding devices at the downdrops of the current conductors. The copper-plated steel strip with a cross-section of 30x4 mm, combining 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.
- According to EIC-7 issue, par.1.7.55 - Grounding devices for protective grounding of electrical installations for buildings and structures and the 2nd and 3rd categories lightning protection of these buildings and structures, as a rule, shall be common.
- If there are concrete-steel constructions, they shall be connected to down conductors/grounding device.
- Connection to the grounding device is carried out using ZZ-005-064 clamps.
Results of calculation performed using the software developed by the Krzhizhanovsky Energy Institute (OAO ENIN):
lightning discharge density into the ground is 4 strikes/sq. km per year.
Total number of strikes into the system is 0.071 (once every 14 years).
The total number of breakouts into the system is 0.0067 (once every 149 years).
The probability of a breakout into the system's facilities is 0.095.
The system reliability is 0,905.
Ground terminal resistance calculation:
Ом - Ohm
Верт - Vert
Гор - Hor
ЗУ - GA
The design resistance of the grounding arrangement is 1,78 Ohm.
Figure 2 shows hardware layout.
Table 1 includes the list of required hardware and materials.
Условные обозначения - Key
Молниеприемник-мачта высотой 2 м на конек - 2 m lightning arrester mast for rood ridge
Проволока стальная омедненная диаметром 8 мм - Steel copper-plated wire, dia 8 mm
Универсальный зажим-держатель для проводника - Multipurpose holder clamp for conductor
Фальцевая клемма для крепления к металлическим конструкциям - Flange terminal for securing to metal structures
Зажим-хомут - Collar clamp
Полоса стальная омедненная сечением 30х4мм - Steel copper-plated bar, cross-section 30 x 4 mm
Зажим для подключения проводника - Clamp for conductor connecting
Опуск токоотвода - Current collector downdrop
… заземлитель длиной 3 м … 3 m grounding electrode
Figure 2. Layout of the equipment for the lightning protection of the rotators' camp in the Yamal-Nenetsk Autonomous District
Table 1. List of materials needed for all building sections.
Do you have any questions about lightning protection of the rotators' camp? Please, contact the ZANDZ Technical Center!
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