Introduction:
Lightning strike is a natural phenomenon of sudden discharge of charges from highly concentrated cloud or any objects. Lightning cannot be avoided but the damages can be reduced by proper preventive measures. Tank farms consist of metal tanks of different sizes and the inflammable materials are stored in this tank of different quantity. In such farms, the sudden increase in temperature due to the passage of lightning impulse current may also result in accidents. Hence for such highly sensitive areas, the lightning protection system will be isolated from the structure to be protected which is generally termed as an Isolated Lightning Protection System.
Isolated lightning protection system:
- In an isolated LPS, the air terminal and down conductors are isolated from the structure to be protected.
- An isolated lightning protection system is preferred for structures on which the effect sudden temperature rise on the down conductor or the electromagnetic due to lightning impulse currents may cause fire accidents or explosions.
- For the structures which contain explosive materials, isolated lightning protection system is preferred.
- In an Isolates LPS, the air terminal is generally installed on a free standing mast adjacent to the structure to be protected in order to maintain electrical separation.
- The separate distance between the air termination or down conductor and the structural metal parts, may be calculated as per IS/IEC 62305-3.
Catenary wires can also be used as air terminals in an isolated LPS.
Follow Us