Is lightning protection really needed for a mushroom farm? In order to answer this question we will study the components of mushroom manufacturing complex.
A mushroom farm of a full cycle contains the following structures: growing site, substrate manufacture site, warehouse and dock.
The major part of electronic and special equipment, as well as ventilation and conditioning equipment is located in growing and manufacture sites, therefore, they are more subject to lightning. Growing cycle, stocking, shipment must be continuous, that is why, each structure must be protected from lightning in order to prevent from financial loses and down time.
See how our ZANDZ Technical center designed mushroom farm lightning protection. We will show you the offered solution on the example of a substrate manufacture site.
Calculation of lightning protection and grounding for a mushroom farm.
Calculations of lightning protection for a mushroom farm are made in accordance with the following documents:
- "Electrical Installation Code" EIC 7th ed. (hereinafter - EIC).
- "Instructions for organization of lightning protection of buildings, structures and industrial communications" IS 153-34.21.122-2003 (hereinafter IS).
- "Instructions for lightning protection of buildings and structures" AD 34.21.122-87 (hereinafter - AD).
Lightning arresters are used for protection of structures from lightning strikes. A lightning arrester usually consists of a lightning rod, intercepting the lightning strike, a down conductor and a ground electrode. All these elements allow to safely drain lightning current into the ground without a damage for the protected object.
The local lore museum refers to traditional objects from the point of view of lightning protection in accordance with IS and to the third category of lightning protection in accordance with AD.
Lightning protection system description for a mushroom farm
The set of measures to provide the required lightning protection is offered by the following solutions:
- Lightning protection of the object is performed in the form of a lightning protection mesh with the help of a steel copper-bonded wire 8 mm in diameter laid with the pitch of not more than 12x12 m. The mesh is made the way so the current would have at least two different ways to the ground electrode.
- Installation of 3 rod lightning rods 7 m high, fixed to the wall, is carried out for the protection of erection between the axes 3-4. It is taken into account that 1, 5 m of the lightning rods height is used for fixation.
- Down conductors from the mesh to the ground electrode are laid with the distance not less than 25 m along the perimeter of the building.
- Fixation of down conductors is performed (installation distance 0.6-1 m):
- To connect rolled metal over the length and in the mesh nodes, a universal clamp GL-11551A is used.
- All metal elements placed on the roof (stairs, boots, railing) must be connected to lightning protection mesh with the help of ZZ-005-064 clamps.
The set of measures on the provision of the necessary requirements to the grounding device is presented by the following solutions:
- Installation of a grounding device consisting of a horizontal electrode (copper bonded tape 4x30 mm), 0.5 meter deep laid along the perimeter of the building 1 m from the foundation.
- In accordance with clause 2.13 of the AD, a circuit without installation of vertical electrodes is enough.
- Interconnection of horizontal electrodes is carried out by using clamp ZZ-005-064.
- The down conductor is connected to the galvanized tape protruding from the ground with the help of GL-11562A clamp.
- The structure of the grounding device corresponds to item 1.7.55 of EIC. Grounding devices for protective grounding and lightning protection grounding are common.
The layout of elements in the lightning protection system and the grounding device is shown in Figure 1.
Figure 1. Plan with the layout of lightning protection elements and grounding device
Components for lightning protection and grounding of the mushroom farm
Do you have any questions on grounding and lightning protection of a mushroom farm? Please contact our ZANDZ Technical center!