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Concepts of Lightning and Surge Protection

Concepts of Lightning and Surge Protection

Lightning strokes, which amount to 200 kA or 300 kV, cause hazards for the equipment or location, so lightning protection is vital for operation.

Let's commence with the initial note in regards to what is lightning and why lightning protection is really important. Principle phenomenon behind lightning is always that charges accumulated in the cloud as well as the earth are equal and opposite. This forms a non-uniform potential gradient surface via a flight. In the event the gradient is larger compared to potential in the surface, the breakdown occurs and a "streamer" flows in the cloud for the earth.

A primary stroke occurs when the lightning hits the electricity systems directly that the immense potential will result in destruction with the equipment or even the facility. In comparison, an indirect stroke occurs from the lightning discharges from the proximity of the power line or from electrostatic discharge around the conductor due to charged clouds.

The main power system elements requiring lightning protection are power feeds, security systems, telephone lines, data and control systems and RF cables.

Strategies to Lightning Protection. The rolling sphere technique is used for identifying the precise keeping of the lightning and surge protection devices close to the equipment under operation.

Protection in the power line against direct strokes is thru a ground wire or protector tube. The previous produces electrostatic screening, that is suffering from the capacitances of the cloud to line as well as the line to ground. The second forms an arc relating to the electrodes, causing gas deionisation.

Rooftop/Frame Protection. It can be interesting to notice that the building and rooftop frame or cladding is preferably metal than insulation type.

Installing of a finial near the top of the energy tower should have a nominal amount distance of a single.5 m higher than the highest antenna or lights. A real rooftop or building frame consists of reinforced steel for cover purpose.

Wooden towers without downconductors could potentially cause a hearth hazard, because they route the incoming charges to ground. In principal, for non-metallic roofs, proper downconductors needs to be installed with the appropriate location and height.

Device Protection. Antenna lightning protection is provided through spark gap, the gas discharge tube and quad-wavelength shorted stub. The 1st method uses ball points to ensure if your strike occurs, high potential forms together as well as the ground. The 2nd method causes gas deionisation through arc formation involving the electrodes. The last method uses a coax transmission line over the transmission line so that system bandwidth is narrow.

A lightning arrester is a device offering lightning protection by regulating spark gaps. These devices classification may range from rod gap, horn gap and valve type to metal oxide lightning arresters.

Earthing and Bonding Solutions. Now let us discuss how earthing and bonding solutions for lightning protection must be afforded. The design of earth rods, terminals or clamps should be you might say to route the incoming transients to earth to minimise step and touch potentials. The geometric measurements chosen should adhere to the IEEE and NFPA standards. Any earthing system must have proper bonding, as ground potential rise can not be compensated. Again, the quantity of interconnects and spacing ought to be designed per the lightning standards.

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