Lightning protection and grounding of a container filling station

Very often you can find container filling stations on the road (CFS). They may be under roof or under the open air. It is unsafe to be near such a station during a thunderstorm, because at a lightning strike, an explosion will definitely happen! One of our clients set our Technical center a task to secure the station and the staff from such a fate in the village Vostochny. Let's study the solution of this problem in more detail!

Picture of CFS example

Task:

It is necessary to perform lightning protection and grounding.
Object: Container filling station (CFS).
Dimensions of the platform with the container:

Length: 5270 mm;
width: 3340 mm;
height: 3300 mm.

Power supply - 380 V.
Type of soil: clay loam (soil resistivity - 100 Ohm * m).

Solution:

The calculations were performed in accordance with the EIC 7th ed., IS 153-34.21.122-2003 "Instructions for lightning protection of buildings, structures, and industrial communications" (hereinafter IS) and AD 34.21.122-87 "Instruction for lightning protection of buildings and structures" (hereinafter AD).

CFS refer to special objects, presenting danger to the immediate surrounding, in terms of lightning protection in accordance with the IS and to category 2 according to the AD.

According to EIC-7, p. 1.7.103. The total spreading resistance of the ground electrodes (including natural) of all repeated groundings of the PEN conductor of each overhead line at any time of the year should not exceed 10 ohms at line voltage of 380 V of the three-phase power supply or 220 V of a single-phase power source.

Set of measures:

Installation of a rod air terminal-mast,15 meters high. The distance from the air terminal to the CFS not less than 3 m according to the AD, p.2.3.
The grounding device is designed as a contour around the object with the installation of 4 electrodes L = 3 m, D = 14 mm, united by a horizontal conductor.

Calculation of grounding device resistance:

Calculation of grounding device resistance

The design resistance of the grounding device is 7.734 ohms, which is less than the permissible resistance of 10 ohms.

Results of calculation of the protection zones in accordance with the IS:

Air terminal-mast ZZ-201-015: h = 15 m;
Height of the cone according to the IS chart. 3.4: h0 = 0,8 · h = 12 m;
The radius of the cone according to the IS chart. 3.4: r0 = 0,8 · h = 12 m.

The radius of the horizontal cross-section rx at the height of hx = 3.3 m for the protection zone of required security is determined by:

Calculation of grounding device resistance-2

protection zone from a direct lightning strike is shown in Fig.1.

Arrangement of lightning protection and grounding equipment, protection zone

Figure 1 - Arrangement of lightning protection and grounding equipment, protection zone

Зона защиты – protection zone
молниеприемник-мачта высотой 15 м – air-terminal mast 15 m high
Проволока омедненная стальная диаметром 10 мм – copper bonded steel wire, diameter 10 mm
Электрод- electrode

The list of equipment and required materials:

№	Fig.	Product item	Name	Quantity, pcs.
1		ZZ-201-015	ZANDZ Vertical lightning rod 15m (galvanized steel;. with embedded details under the foundation)	1
2		ZZ-001-065	ZANDZ Copper-bonded threaded ground rod (D14; 1,5 m)	8
3		ZZ-002-061	ZANDZ Threaded coupler	5
4		ZZ-003-061	ZANDZ Starting tip	4
5		ZZ-004-060	ZANDZ Driving stud for a breaker hammer	2
6		ZZ-006-000	ZANDZ Conductive grease	1
7		ZZ-008-000	ZANDZ Cup for a breaker hammer (SDS max)	1
8		ZZ-005-064	ZANDZ Clamp for connecting conductor (up to 40 mm)	5
9		ZZ-007-030	ZANDZ Waterproof tape	2
10		ZZ-500-103	ZANDZ Grounding conductor (3m; S25, single-core, with a tip for the bolt D8)	1
11		GL-11150-20	GALMAR Copper-bonded wire (D 10 mm / S 50 mm²; coil 20 meters)	2