Rules of Lightning and Surge Protection
Lightning strokes, which figure to 200 kA or 300 kV, cause hazards for the equipment or location, so lightning protection is vital for operation.
Let us start with the original note to what is lightning and why lightning protection is really important. Principle phenomenon behind lightning is always that charges accumulated through the cloud along with the earth are equal and opposite. This forms a non-uniform potential gradient surface up. If the gradient is larger as opposed to potential with the surface, the breakdown occurs plus a "streamer" flows in the cloud towards the earth.
A primary stroke takes place when the lightning hits the energy systems directly that this immense potential may cause destruction from the equipment or perhaps the facility. On the other hand, an indirect stroke occurs from the lightning discharges inside the proximity of the power line or from electrostatic discharge about the conductor because of the charged clouds.
The key power system elements requiring lightning protection are power feeds, security systems, telephone lines, data and control systems and RF cables.
Types of Lightning Protection. The rolling sphere strategy is useful for identifying the precise placement of the lightning and surge protection devices close to the equipment under operation.
Protection from the power line against direct strokes is thru a ground wire or protector tube. The former produces electrostatic screening, that's suffering from the capacitances with the cloud to line and the line to ground. The second forms an arc between the electrodes, causing gas deionisation.
Rooftop/Frame Protection. It's interesting to make note of that the building and rooftop frame or cladding is preferably metal than insulation type.
Installing of a finial towards the top of the electricity tower needs to have the very least distance of merely one.5 m above the highest antenna or lights. This type of rooftop or building frame is made of reinforced steel for protection purpose.
Wooden towers without downconductors might cause a fire hazard, because they route the incoming charges to ground. In principal, for non-metallic roofs, proper downconductors should be installed in the appropriate location and height.
Device Protection. Antenna lightning protection is given through spark gap, the gas discharge tube and quad-wavelength shorted stub. The first method uses ball points so that if a strike occurs, high potential forms between them as well as the ground. The other method causes gas deionisation through arc formation between your electrodes. The final method works on the coax transmission line throughout the transmission line in order that system bandwidth is narrow.
A lightning arrester is often a device offering lightning protection by regulating spark gaps. These devices classification may cover anything from rod gap, horn gap and valve type to metal oxide lightning arresters.
Earthing and Bonding Solutions. Now learn about how earthing and bonding solutions for lightning protection needs to be afforded. The appearance of earth rods, terminals or clamps ought to be in a way to route the incoming transients to earth to minimise step and touch potentials. The geometric measurements chosen should conform to the IEEE and NFPA standards. Any earthing system really should have proper bonding, as ground potential rise cannot be compensated. Again, the volume of interconnects and spacing needs to be designed per the lightning standards.
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