2015-08-21
185
Lightning-proof and protection from atmospheric electric is ensured by:
- installing lightning-rod;
- installing metallic grounded cells around outside objects;
- grounding facilities inside the building;
- making electric connection among close metallic elements of the building, such as pipelines, and grounding them.
Protection from lightning stroke is made with separate lightning-rods or ropes set on building.
Lightning-rods are selected in accordance to building’s plan. Lightning-rods of objects referred to category I are not set on the building however they should have dielectric stand 8 m above the building, grounding resistance up to 10 ohm and be situated 8 m as nearest. Grounding resistance is to be 20 ohm as maximum in category III.
To protect buildings and structures referred to categories II and III from lightning stroke lightning-rods are set separately or on the building as not insolated rods and ropes, or as metallic cell made from wire of 6-8 mm in diameter.
Connecting nearly situated metallic components of building, such as pipelines, in the places where less 10 cm is between them along every 20 - 25 m prevents electric induction. Resistance of that connection should be 0.03 ohm as maximum.
Grounding metallic parts of communication and other systems prevents transferring high electric potential inside building.
Fire safety systems
