Sanford Callesen posted an update 2 months, 2 weeks ago
Lightning strokes, which total 200 kA or 300 kV, cause hazards for the equipment or location, so lightning protection is vital for operation.
Let’s focus on the first note as to what is lightning and why lightning protection is indeed important. The fundamental phenomenon behind lightning is the fact that charges accumulated from the cloud as well as the earth are equal and opposite. This forms a non-uniform potential gradient surface in the air. If the gradient is greater compared to the potential from the surface, the breakdown occurs along with a "streamer" flows in the cloud towards the earth.
A direct stroke happens when the lightning hits the ability systems directly the immense potential will result in destruction in the equipment or facility. As opposed, an indirect stroke occurs from the lightning discharges in the proximity from the power line or from electrostatic discharge for the conductor as a result of charged clouds.
The principle 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 method is used for identifying the exact keeping the lightning and surge protection devices at the equipment under operation.
Protection from the power line against direct strokes is via a ground wire or protector tube. The first kind produces electrostatic screening, that’s afflicted with the capacitances of the cloud to line as well as the line to ground. Rogues forms an arc between the electrodes, causing gas deionisation.
Rooftop/Frame Protection. It really is interesting to notice that the building and rooftop frame or cladding is preferably metal than insulation type.
Installation of a finial on top of the energy tower really should have a nominal amount distance of 1.5 m across the highest antenna or lights. This type of rooftop or building frame consists of reinforced steel for defense purpose.
Wooden towers without downconductors could potentially cause a fire hazard, as they route the incoming charges to ground. In principal, for non-metallic roofs, proper downconductors must be installed with the appropriate location and height.
Device Protection. Antenna lightning protection emerges through spark gap, the gas discharge tube and quad-wavelength shorted stub. The initial method uses ball points in order that if a strike occurs, high potential forms between them as well as the ground. The next method causes gas deionisation through arc formation relating to the electrodes. The very last method works on the coax transmission line through the transmission line to ensure that system bandwidth is narrow.
A lightning arrester is often a device offering lightning protection by regulating spark gaps. The unit classification may range from rod gap, horn gap and valve type to metal oxide lightning arresters.
Earthing and Bonding Solutions. Now let’s find how earthing and bonding solutions for lightning protection ought to be afforded. The style of earth rods, terminals or clamps should be in ways to route the incoming transients to earth to minimise step and touch potentials. The geometric measurements chosen should abide by the IEEE and NFPA standards. Any earthing system should have proper bonding, as ground potential rise is not compensated. Again, the number of interconnects and spacing needs to be designed per the lightning standards.
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