Lightning strokes, which total 200 kA or 300 kV, cause hazards on the equipment or location, so lightning protection is essential for operation.
Why don’t we focus on the initial note to what is lightning and why lightning protection can be so important. Principle phenomenon behind lightning is charges accumulated through the cloud and also the earth are equal and opposite. This forms a non-uniform potential gradient surface up. In the event the gradient is greater compared to potential of the surface, the breakdown occurs plus a “streamer” flows through the cloud towards the earth.
A direct stroke takes place when the lightning hits the energy systems directly how the immense potential can cause destruction of the equipment or facility. In contrast, an indirect stroke occurs from the lightning discharges in the proximity of the power line or from electrostatic discharge about the conductor due to the charged clouds.
The main power system elements requiring lightning protection are power feeds, alarm systems, telephone lines, data and control systems and RF cables.
Strategies to Lightning Protection. The rolling sphere method is useful for identifying the actual positioning of the lightning and surge protection devices close to the equipment under operation.
Protection with the power line against direct strokes is by a ground wire or
protector tube. The first kind produces electrostatic screening, that’s
suffering from the capacitances of the cloud to line as well as the line to
ground. Rogues forms an arc between your electrodes, causing gas deionisation.
Rooftop/Frame Protection. It’s interesting to notice the building and
rooftop frame or cladding is preferably metal than insulation type.
Setting
up a finial at the top of the power tower really should have the absolute
minimum distance of a single.5 m above the highest antenna or lights. A real
rooftop or building frame is constructed of reinforced steel for cover 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 needs to be installed at the appropriate location
and height.
Device Protection. Antenna lightning protection is supplied
through spark gap, the gas discharge tube and quad-wavelength shorted stub. The
very first method uses ball points to ensure that if a strike occurs, high
potential forms between them along with the ground. The other method causes gas
deionisation through arc formation relating to the electrodes. The very last
method uses a coax transmission line throughout 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 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 needs to be afforded. The style of
earth rods, terminals or clamps must be in a way 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 needs to have proper bonding, as ground potential rise cannot be
compensated. Again, the amount of interconnects and spacing must be designed per
the lightning standards.
To get more information about coc tiep dia
chong set you can check the best resource.
Kim Thu Set 