Rules of Lightning and Surge ProtectionLightning strokes, which total 200 kA or 300 kV, cause hazards to the equipment or location, so lightning protection is important for operation.
Why don't we begin with your initial note as to what is lightning and why lightning protection can be so important. The basic phenomenon behind lightning is always that charges accumulated from your cloud along with the earth are equal and opposite. This forms a non-uniform potential gradient surface via a flight. When the gradient is larger than the potential of the surface, the breakdown occurs and a "streamer" flows through the cloud for the earth.
A direct stroke happens when the lightning hits the electricity systems directly that this immense potential will cause destruction with the equipment or even the facility. In comparison, an indirect stroke occurs from the lightning discharges in the proximity of the power line or from electrostatic discharge around the conductor due to charged clouds.
The primary power system elements requiring lightning protection are power feeds, home alarm systems, telephone lines, data and control systems and RF cables.
Methods of Lightning Protection. The rolling sphere strategy is employed for identifying the exact keeping 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 first kind produces electrostatic screening, that is impacted by the capacitances in the cloud to line and the line to ground. Rogues forms an arc involving the electrodes, causing gas deionisation.
Rooftop/Frame Protection. It is interesting to note that the building and rooftop frame or cladding is preferably metal than insulation type.
Setting up a finial near the top of the ability tower should have a nominal amount distance of merely one.5 m across the highest antenna or lights. This kind of rooftop or building frame is made from reinforced steel for protection purpose.
Wooden towers without downconductors could cause a fireplace hazard, as they route the incoming charges to ground. In principal, for non-metallic roofs, proper downconductors needs to be installed at 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 very first method uses ball points to ensure if a strike occurs, high potential forms bewteen barefoot and shoes and the ground. The 2nd method causes gas deionisation through arc formation involving the electrodes. The final method uses a coax transmission line throughout the transmission line so that system bandwidth is narrow.
A lightning arrester is really a device offering lightning protection by regulating spark gaps. The unit classification may vary 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 must be afforded. The design of earth rods, terminals or clamps needs to be you might say to route the incoming transients to earth to minimise step and touch potentials. The geometric measurements chosen should comply with the IEEE and NFPA standards. Any earthing system needs to have proper bonding, as ground potential rise can't be compensated. Again, the amount of interconnects and spacing should be designed per the lightning standards.
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